This research was supported by NASA (NNX15AC17G to CMD), and by NASA cooperative agreement NCC 9-58 (E000010 to CMD, NBPF02802 and NBPF04201 to RDH) with the National Space Biomedical Research Institute.

Laboratory animal care was according to Public Health Service (PHS) Policy on the Humane Care and Use of Laboratory Animals. All procedures were carried out in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. The Institutional Animal Care and Use Committee of the Johns Hopkins University approved the protocol and all procedures. Johns Hopkins also maintains accreditation of their program by the Association for the Assessment and Accreditation of Laboratory Animal Care (AAALAC).
1. Animals
<ol>
	<li>Use adult male Long Evans rats (approximately 10 - 12 weeks old at the start of behavioral training), although other strains are suitable, including inbred rats.</li>
	<li>Upon arrival in the colony, house rats singly in approved caging and rooms, due to the food restriction needs described below. Acclimate animals to the housing situation as well as handling for several days prior to starting the food restriction procedure (approximately 7 days).</li>
	<li>Provide rat chow ad libitum for 1 - 2 weeks to allow rats to achieve a &#34;free-feeding&#34; weight. Once at this weight, restrict food access to reduce rats&#39; weights, over 1 - 2 weeks, to 85 - 90% of the free-feeding weight. Maintain animals at 85 - 90% of their free-feeding weights during behavioral training and testing. Start with 15 - 18 g of food per day and adjust this amount based on whether or not a rate is maintaining its target weight. 
	NOTE: Food restriction normally requires approval of one&#39;s institutional ACUC or other regulatory body prior to starting the restriction.</li>
	<li>Weigh animals daily and record the weight on weight sheets. Ensure weighing is done at the same time and on the same scale each day prior to the start of any behavioral training or feeding. 
	NOTE: Only start pretraining (below) when the animals have achieved their target weights. This practice allows for immediate corrections to food amounts for animals that are either under or over their target weights. It also provides a method to determine if rats are maintaining weights at 24-h intervals. Also avoid weighing rats at different times of the day; it will result in dramatic differences in weight, incorrect feedings, and poor behavioral performances.</li>
	<li>Provide fresh water at all times in the home cage by the use of glass or plastic bottles with rubber stopper tops and sipper tubes.</li>
	<li>When sessions are not conducted (e.g., weekends, holidays), feed the rats their normal allotment of rat chow to maintain weight stability. Weigh rats to determine if more food is needed to maintain weight during these times.</li>
</ol>
2. Equipment and Software
<ol>
	<li>Use standard modular operant chambers equipped with one nose poke key, a house light, and a pellet dispenser (i.e., feeder).</li>
	<li>Place the modular nose poke key on either side of the centrally located pellet dispenser; ensuring that this placement remains consistent in other operant chambers and across studies. Here, the nose poke key is on the left hand side of the pellet dispenser.</li>
	<li>Place the modular house light high on the back wall of the chamber so as to not interfere with other behaviors.</li>
	<li>Use rat food pellets (e.g., Noyes 45-mg pellets or similar) for reinforcement. The feeder model determines food pellet size, but most rat feeders use 45-mg food pellets (mouse feeders typically use 20-mg food pellets). Use standard chow pellets, but other pellets can be purchased (e.g., sucrose) for different experimental manipulations.</li>
	<li>Control stimulus presentations, nose poke response inputs, reinforcement delivery, and data collection via an interface connected to a computer. Contact the authors for specific information regarding behavioral programs written with a programming language specifically designed for behavioral testing (see Table of Materials and Reagents). 
	NOTE: It is important to record independent and dependent variables on a trial-by-trial basis, including animals&#39; response types (e.g., correct responses, premature responses, misses), the response latency, and number of trials presented. When using different strains, sexes or species, these variables can be easily altered to maximize training in almost any type of rodent.</li>
</ol>
3. Pretraining
<ol>
	<li>Assign each animal to an operant chamber where it will be tested each day, and at approximately the same time of day, throughout the experiment.</li>
	<li>Weigh the rat and place it in its specific operant chamber with food pellets in the pellet dispenser. Place 10 - 20 food pellets in the receptacle for the rat to eat.</li>
	<li>For pretraining, set the following parameters to low, fixed values: foreperiod value = 2 s, timeout value = 2 s, limited hold = 10 s.</li>
	<li>Start the computer program to control presentation of the house light, nosepoke key illumination, and automatic food pellet delivery. 
	NOTE: It is best to have the behavioral program set to a level that allows for frequent reinforcements for the majority of responses produced by the animal, such that the nose poke key is illuminated for a relatively long duration of time (e.g., 10 s). This increases the likelihood that the rat will poke the key while it is illuminated, resulting in the delivery of a food reinforcer by the computer program.</li>
	<li>Once the rat finishes the food pellets, start the shaping process by reinforcing the rat when it approaches the food receptacle or the nose poke key. Here, manually shape each rat, which means that an experimenter watches the rat&#39;s behavior (by leaving the sound attenuating cubicle doors open) and delivers pellets from the feeder as quickly as possible after the rat emits the desired behavior. Deliver pellets from a button on the feeder itself, through a hand-held switch that is wired to the feeder, or through the computer software used to control the behavioral contingencies by clicking on the appropriate output on the interface.</li>
	<li>Using the method of shaping by successive approximations, provide a food reinforcer for behavior changes that are successive approximations to the final desired behavior23. For example, once the rat is reliably retrieving food pellets from the food receptacle, start reinforcing only movement towards or around the nose poke key, and no longer reinforce approaches to the food receptacle. Here, shape rats to move to the left after retrieving a food pellet, since the nose poke key is located to the left of the food receptacle in the operant chambers. 
	NOTE: Even though the experimenter is delivering food reinforcers during the beginning of pretraining, the computer program is still running and controlling the house light, nosepoke key, and feeder. If a rat pokes the key, the computer program will reinforce it automatically. Experimenter-reinforced behaviors are only those leading the rat to poke the illuminated key, such as sniffing the key or around it, moving the head near the key or towards it, etc.</li>
	<li>Determine the amount of food earned during the pretraining session by counting the number of pellets delivered manually plus any pellets delivered automatically by the computer software (i.e., pellets delivered because the rat poked the illuminated key). Multiply this number by 0.045 g to determine total food earned (e.g., 30 pellets x 0.045 g = 1.35 g).</li>
	<li>Remove the rat and place it back in its home cage. Subtract, by hand, the amount of food earned (see 3.7) in the behavioral session from the rat&#39;s daily food allotment. Feed the remainder of the food allotment to the rat after the behavioral training session. Feed at a minimum of 30 min after the conclusion of the behavioral session to avoid home cage food reinforcement immediately after nonproductive sessions.</li>
	<li>Clean the operant chamber daily with a gentle disinfectant (e.g., soap and water). Use 70% EtOH sparingly, given that it can damage the operant chambers. Check the nose poke key daily in order to maintain proper working condition and clean with disinfectant when needed, since a key that sticks or gets locked in place will disrupt an animal&#39;s performance if not repaired quickly.</li>
	<li>Shape each rat in this manner until the rat emits 40 - 50 correct computer-reinforced (not manually or experimenter-reinforced) responses on the illuminated key, retrieves each food pellet, and returns to and pokes the nose poke key without additional shaping. Typically, rats require approximately 2 - 3 30-min sessions to reach these criteria (see Figure 2). 
	NOTE: Manual delivery of food pellets is not needed after the rat is reliably poking the key and receiving food reinforcement delivered by the computer program.</li>
</ol>
4. rPVT Training
<ol>
	<li>Once shaped, start the rat at a fixed, relatively short foreperiod interval and TO value (e.g., 2 s) on the next 30-min session until the rat completes 8 out of 10 correct trials. For each of these trials during the training, illuminate the nose poke key for a period of time long enough for a rat to make a response. Here, keep the key illuminated for 9 seconds; this response window is also called the limited hold (LH).</li>
	<li>Use a relatively short time out (TO; e.g., 2 s) as a punishment for premature responses, or responding prior to the illumination of the nose poke key. During the TO, rats have no opportunity to earn food. Here, the TO and foreperiod value are the same duration during these training sessions and change at the same rate.</li>
	<li>Once the rat completes 8 out of 10 correct trials, increase the foreperiod and TO by 0.1 s (i.e., to 2.1), while shortening the LH by 0.1 s (i.e., to 8.9). It is best to use a computer program that can automatically make these adjustments during a session. 
	NOTE: When training mice on the rPVT, a longer ITI is employed since mice require more time to consume food pellets. Here, use a 30 s ITI for training and testing male C57BL/6J. Additionally, since a mouse may weigh ~ 20 g, it will consume significantly fewer pellets during a session. Therefore, shorten a typical session by having it end when a maximum of 50 pellets are earned; the criterion for increasing the foreperiod and TO is also changed to be 4 out of 5 correct trials before increasing the foreperiod and TO by 0.1 s.</li>
	<li>Once the 30 min session is over, record the final foreperiod the rat reached during the training session (e.g., 4.2 s), either in a spreadsheet or by hand on a data sheet, and the amount of food earned, which is calculated by multiplying the number of correct trials times 0.045 g (e.g., 100 correct trials x 0.045 g = 4.5 g). Subtract this food amount from the rat&#39;s daily allotment and feed the rat the remaining food in the home cage. 
	NOTE: The daily data files record the final foreperiod reached by each rat. The calculation to determine the amount of food earned in the session can be done automatically by the computer program or by hand using the equation above. Food earned is subtracted by hand from each rat&#39;s the daily food allotment.</li>
	<li>On the following day, start the 30 min training session with a foreperiod that is 300 ms lower than the value the rat ended on in the previous session. For example, if the rat ended at 4.2 s, this session starts at 3.9 s. Continue increasing the foreperiod by 0.1 s as the rat completes 8 out of 10 correct trials at each foreperiod, until rats reach a foreperiod of 10 s. In this way, rats will experience all of the possible foreperiods. 
	NOTE: When rats reach a foreperiod of 9.7 - 10 s, the TO remains at 8 s and the LH is 1.5 s.</li>
	<li>At the end of each session, check the rat&#39;s daily performance during this time by examining the percentage of correct trials, premature trials, and misses. Rats commonly maintain an average of 40 - 90% correct responses during these training sessions, with the average percent correct increasing steadily across training. Here, export the daily data for each rat to a spreadsheet that calculates these percentages in order to track daily session performance.</li>
	<li>Once the rat reaches a foreperiod of 10 s, start the next subsequent 30 min session with the foreperiods presented at random intervals, starting with foreperiods between 7 - 10 s. Ensure that the TO and LH remain at 8 and 1.5 s, respectively. Here, the computer program controlling the behavioral contingencies automatically switches from presenting ascending foreperiods to variable foreperiods once each rat reaches the 8 out of 10 criterion at the 10 s foreperiod.</li>
	<li>Once the rat maintains at least 70% correct with randomly presented foreperiods between 7 - 10 sec, change the program to present foreperiods at random intervals, starting with foreperiods between 5 - 10 s. Examine each rat&#39;s daily performance during this time because this change often happens within a session.</li>
	<li>After the rat maintains 70% correct, change the program again to present the full range of foreperiods (3 - 10 s) at random intervals during the 30 min session. In a manner similar to 4.8, examine each rat&#39;s daily performance during this time because this change often happens within a session. 
	NOTE: The computer software controlling the behavioral contingencies automatically makes these changes based on each rat&#39;s performance (e.g., 4.7 - 4.9). It is important to only make the change in 4.9 when a rat&#39;s success rate is high (&#62;70% correct), since rats frequently adopt the strategy of responding randomly in time, instead of properly waiting and attending to the stimulus. If a rat&#39;s success rat is low, repeat 4.7 - 4.9.</li>
	<li>For the Acquisition Criteria, define the baseline performances as stable when, on 4 out of 5 daily sessions within a week, rats&#39; percentage of correct responses is 75% or greater during a session and the percentage of premature responses is less than 30%.</li>
</ol>
5. Data Analysis for Basic Response Measures
<ol>
	<li>To assess behavioral performances during acquisition, use repeated-measures ANOVAs, with the repeated factor of either Session, Time on Task Value, or Foreperiod Value for each performance measure described below. 
	NOTE: Here, the studies use both within- and between-subjects designs, where we compare all animals to their own baselines after an experimental condition and compare experimental animals to control animals following the same manipulation. When stable behavioral baselines are achieved, use of within-subjects designs will limit the number of rats needed.</li>
	<li>Define premature responses as responses prior to the onset of the key light or within the first 150 ms of the key light being on.</li>
	<li>Define correct responses as responses made after the key light comes on, with a minimal latency greater than 150 ms, and a maximal latency of the response window length; here, 1,500 ms.</li>
	<li>Define misses (or omissions) as trials on which the subject fails to make a response.</li>
	<li>Define response latencies as the elapsed time (in ms) from light onset to depression of the nose poke key; also called reaction time (RT).</li>
	<li>Define total trials as the number of premature responses plus correct responses plus misses. 
	NOTE: In human PVT performances, premature responding and lapses in attention can be quite rare, and investigators most often report only the actual raw frequencies of these measures. However, this is not the case in performances with rats. To allow for comparisons between different versions of the rPVT in the literature, rats&#39; performance measures are presented here as a percentage of total trials. Use of a computer program that can record and label each of these items on a trial-by-trial basis for subsequent analysis is preferred, since rats will complete over 200 trials per 30 min session and will often meet the criteria to move to another step in the training procedure within a session.</li>
</ol>
6. Additional Computed Performance Measures
<ol>
	<li>For a 30 min behavioral session, define lapses as correct responses in which the RT was greater than twice the mean reaction time for each rat&#39;s session (done after a session); also include missed trials in the lapse calculation. 
	NOTE: In the human PVT, lapses are typically defined as reaction times (RT) &#62; 500 ms4. For rodents, it is best to perform post-hoc comparisons to each rat&#39;s mean RT - acquired from the trial-by-trial analysis described above - instead of comparing them to a threshold value, due to the variability in RTs from individual rats. This method is similar to lapses in other published versions of the rPVT15,16. Here and in other published versions, lapses also include missed trials (lapses = responses with RTs &#62; twice the mean RT for a session, plus misses) because missed trials in the human PVT are recorded as lapses, as well.</li>
	<li>Determine the estimated false alarm rate by calculating the percentage of premature responses that occur during the actual 3 - 10 s interval when a stimulus could have appeared. 
	NOTE: This measure uses a subset of premature responses that occur only during a time when the stimulus could occur, i.e., premature responses that occur within the 3 - 10 s foreperiod window. This measure does not include premature responses prior to the 3 s because the stimulus light would never be illuminated during that time. Here, this subset of premature responses is automatically sorted from all premature responses in a spreadsheet computer program.</li>
</ol>

<ol>
	<li>Dinges, D. F., Orne, M. T., Whitehouse, W. G., Orne, E. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temporal+placement+of+a+nap+for+alertness:+contributions+of+circadian+phase+and+prior+wakefulness.">Temporal placement of a nap for alertness: contributions of circadian phase and prior wakefulness.</a> Sleep. 10, 313-329 (1987).</li><li>Dinges, D. F., Powell, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microcomputer+analyses+of+performance+on+a+portable,+simple+visual+RT+task+during+sustained+operations.">Microcomputer analyses of performance on a portable, simple visual RT task during sustained operations.</a> Behav Res Method Inst Comp. 17, 652-655 (1985).</li><li>Kribbs, N. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+one+night+without+nasal+CPAP+treatment+on+sleep+and+sleepiness+in+patients+with+obstructive+sleep+apnea.">Effects of one night without nasal CPAP treatment on sleep and sleepiness in patients with obstructive sleep apnea.</a> Am Rev Respir Dis. 147, 1162-1168 (1993).</li><li>Basner, M., Dinges, D. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Maximizing+sensitivity+of+the+psychomotor+vigilance+test+(PVT)+to+sleep+loss.">Maximizing sensitivity of the psychomotor vigilance test (PVT) to sleep loss.</a> Sleep. 34, 581-591 (2011).</li><li>Basner, M., Mollicone, D., Dinges, D. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Validity+and+Sensitivity+of+a+Brief+Psychomotor+Vigilance+Test+(PVT-B)+to+Total+and+Partial+Sleep+Deprivation.">Validity and Sensitivity of a Brief Psychomotor Vigilance Test (PVT-B) to Total and Partial Sleep Deprivation.</a> Acta Astronaut. 69, 949-959 (2011).</li><li>Dinges, D. F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cumulative+sleepiness,+mood+disturbance,+and+psychomotor+vigilance+performance+decrements+during+a+week+of+sleep+restricted+to+4-5+hours+per+night.">Cumulative sleepiness, mood disturbance, and psychomotor vigilance performance decrements during a week of sleep restricted to 4-5 hours per night.</a> Sleep. 20, 267-277 (1997).</li><li>Drummond, S. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+neural+basis+of+the+psychomotor+vigilance+task.">The neural basis of the psychomotor vigilance task.</a> Sleep. 28, 1059-1068 (2005).</li><li>Jewett, M. E., Dijk, D. J., Kronauer, R. E., Dinges, D. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dose-response+relationship+between+sleep+duration+and+human+psychomotor+vigilance+and+subjective+alertness.">Dose-response relationship between sleep duration and human psychomotor vigilance and subjective alertness.</a> Sleep. 22, 171-179 (1999).</li><li>Lim, J., Dinges, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sleep+deprivation+and+vigilant+attention.">Sleep deprivation and vigilant attention.</a> Ann N Y Acad Sci. 1129, 305-322 (2008).</li><li>Van Dongen, H. P., Dinges, D. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sleep,+circadian+rhythms,+and+psychomotor+vigilance.">Sleep, circadian rhythms, and psychomotor vigilance.</a> Clin Sports Med. 24 (2), 237-249 (2005).</li><li>Van Dongen, H. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Caffeine+eliminates+psychomotor+vigilance+deficits+from+sleep+inertia.">Caffeine eliminates psychomotor vigilance deficits from sleep inertia.</a> Sleep. 24 (7), 813-819 (2001).</li><li>Blatter, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gender+and+age+differences+in+psychomotor+vigilance+performance+under+differential+sleep+pressure+conditions.">Gender and age differences in psychomotor vigilance performance under differential sleep pressure conditions.</a> Behav Brain Res. 168 (2), 312-317 (2006).</li><li>Lim, J., Dinges, D. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sleep+deprivation+and+vigilant+attention.">Sleep deprivation and vigilant attention.</a> Annals of the New York Academy of Sciences. 1129, 305-322 (2008).</li><li>Basner, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mars+520-d+mission+simulation+reveals+protracted+crew+hypokinesis+and+alterations+of+sleep+duration+and+timing.">Mars 520-d mission simulation reveals protracted crew hypokinesis and alterations of sleep duration and timing.</a> Proc Natl Acad Sci U S A. 110, 2635-2640 (2013).</li><li>Christie, M. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microdialysis+elevation+of+adenosine+in+the+basal+forebrain+produces+vigilance+impairments+in+the+rat+psychomotor+vigilance+task.">Microdialysis elevation of adenosine in the basal forebrain produces vigilance impairments in the rat psychomotor vigilance task.</a> Sleep. 31, 1393-1398 (2008).</li><li>Christie, M. A., McKenna, J. T., Connolly, N. P., McCarley, R. W., Strecker, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=24+hours+of+sleep+deprivation+in+the+rat+increases+sleepiness+and+decreases+vigilance:+introduction+of+the+rat-psychomotor+vigilance+task.">24 hours of sleep deprivation in the rat increases sleepiness and decreases vigilance: introduction of the rat-psychomotor vigilance task.</a> J. Sleep Res. 17, 376-384 (2008).</li><li>Oonk, M., Davis, C. J., Krueger, J. M., Wisor, J. P., Van Dongen, H. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sleep+deprivation+and+time-on-task+performance+decrement+in+the+Rat+Psychomotor+Vigilance+Task.">Sleep deprivation and time-on-task performance decrement in the Rat Psychomotor Vigilance Task.</a> Sleep. 38, 445-451 (2015).</li><li>Loomis, S., McCarthy, A., Edgar, D., Tricklebank, M., Gilmour, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Behavioural+evidence+that+modafinil+and+amphetamine+do+not+produce+equivalent+qualities+of+wake+promotion+in+sleep-restricted+rats.">Behavioural evidence that modafinil and amphetamine do not produce equivalent qualities of wake promotion in sleep-restricted rats.</a> Sleep Medicine. 14, 185 (2013).</li><li>Deurveilher, S., Bush, J. E., Rusak, B., Eskes, G. A., Semba, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Psychomotor+vigilance+task+performance+during+and+following+chronic+sleep+restriction+in+rats.">Psychomotor vigilance task performance during and following chronic sleep restriction in rats.</a> Sleep. 38, 515-528 (2015).</li><li>Davis, C. M., Roma, P. G., Hienz, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+rodent+model+of+the+human+psychomotor+vigilance+test:+Performance+comparisons.">A rodent model of the human psychomotor vigilance test: Performance comparisons.</a> J Neurosci Methods. 259, 57-71 (2016).</li><li>Lim, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+brain+fatigue+from+sustained+mental+workload:+an+ASL+perfusion+study+of+the+time-on-task+effect.">Imaging brain fatigue from sustained mental workload: an ASL perfusion study of the time-on-task effect.</a> Neuroimage. 49, 3426-3435 (2010).</li><li>Tucker, A. M., Basner, R. C., Stern, Y., Rakitin, B. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+variable+response-stimulus+interval+effect+and+sleep+deprivation:+an+unexplored+aspect+of+psychomotor+vigilance+task+performance.">The variable response-stimulus interval effect and sleep deprivation: an unexplored aspect of psychomotor vigilance task performance.</a> Sleep. 32, 1393-1395 (2009).</li><li>Skinner, B. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The behavior of organisms: an experimental analysis. , (1938).</li><li>Warm, J. S., Parasuraman, R., Matthews, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vigilance+requires+hard+mental+work+and+is+stressful.">Vigilance requires hard mental work and is stressful.</a> Hum Factors. 50, 433-441 (2008).</li><li>Blatter, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gender+and+age+differences+in+psychomotor+vigilance+performance+under+differential+sleep+pressure+conditions.">Gender and age differences in psychomotor vigilance performance under differential sleep pressure conditions.</a> Behav Brain Res. 168, 312-317 (2006).</li><li>Raymann, R. J., Van Someren, E. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Time-on-task+impairment+of+psychomotor+vigilance+is+affected+by+mild+skin+warming+and+changes+with+aging+and+insomnia.">Time-on-task impairment of psychomotor vigilance is affected by mild skin warming and changes with aging and insomnia.</a> Sleep. 30, 96-103 (2007).</li><li>Beijamini, F., Silva, A. G., Peixoto, C. A., Louzada, F. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+gender+on+psychomotor+vigilance+task+performance+by+adolescents.">Influence of gender on psychomotor vigilance task performance by adolescents.</a> Braz J Med Biol Res. 41, 734-738 (2008).</li><li>Davis, C. M., DeCicco-Skinner, K. L., Hienz, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deficits+in+Sustained+Attention+and+Changes+in+Dopaminergic+Protein+Levels+following+Exposure+to+Proton+Radiation+Are+Related+to+Basal+Dopaminergic+Function.">Deficits in Sustained Attention and Changes in Dopaminergic Protein Levels following Exposure to Proton Radiation Are Related to Basal Dopaminergic Function.</a> PLoS One. 10, 0144556 (2015).</li><li>Stebbins, W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Response+latency+as+a+function+of+amount+of+reinforcement.">Response latency as a function of amount of reinforcement.</a> J Exp Anal Behav. 5, 305-307 (1962).</li><li>Stebbins, W. C., Lanson, R. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Response+latency+as+a+function+of+reinforcement+schedule.">Response latency as a function of reinforcement schedule.</a> J Exp Anal Behav. 5, 299-304 (1962).</li><li>Christie, M. A., McCarley, R. W., Strecker, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Twenty-four+hours,+or+five+days,+of+continuous+sleep+deprivation+or+experimental+sleep+fragmentation+do+not+alter+thirst+or+motivation+for+water+reward+in+rats.">Twenty-four hours, or five days, of continuous sleep deprivation or experimental sleep fragmentation do not alter thirst or motivation for water reward in rats.</a> Behav Brain Res. 214, 180-186 (2010).</li><li>Koban, M., Sita, L. V., Le, W. W., Hoffman, G. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sleep+deprivation+of+rats:+the+hyperphagic+response+is+real.">Sleep deprivation of rats: the hyperphagic response is real.</a> Sleep. 31, 927-933 (2008).</li><li>Moody, D. B., Stebbins, W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Animal Psychophysics, The Design and Conduct of Sensory Experiments. , 277-302 (1970).</li><li>Pfingst, B. E., Hienz, R. D., Kimm, J., Miller, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reaction-time+procedure+for+measurement+of+hearing+I.+Suprathreshold+functions.">Reaction-time procedure for measurement of hearing I. Suprathreshold functions.</a> J Acoust Soc Am. 57, 421-430 (1975).</li><li>Stebbins, W. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Auditory+reaction+time+and+the+derivation+of+equal+loudness+contours+for+the+monkey.">Auditory reaction time and the derivation of equal loudness contours for the monkey.</a> J Exp Anal Behav. 9, 135-142 (1966).</li><li>Hienz, R. D., Weerts, E. M., VandeBerg, J. L., Williams-Blanger, S., Tardif, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Baboon in Biomedical Research. , (2009).</li><li>May, B. J., Huang, A. Y., Aleszczyk, C. M., Hienz, R. D., Klump, G. M., Dooling, R. J., Fay, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Methods of Comparative Acoustics. , 95-108 (1995).</li></ol>

The authors have nothing to disclose.

The methodology described herein results in rPVT performances in rats that compare favorably in many aspects to the typical PVT performance reported in the human literature. Using the present techniques, one can quickly train rats to perform the rPVT, and the performances obtained with these techniques are characterized by clear discriminations (i.e., high levels of correct responding, low levels of both premature responding and lapses). Further, the reaction time distributions obtained with the rPVT are quite s...

The human psychomotor vigilance test (PVT) is a widely used, well-validated tool for measuring vigilance and sustained attention in humans, and was originally developed by Dinges et al. 1-3 for assessing the stability in reaction times and attention (e.g., errors in terms of premature responses and lapses in attention), both within sessions as a whole and across time within individual sessions. Over the years, the human PVT has been modified and updated4-11 to track temporal changes in various aspects attention, and has been demonstrated to be sensitive to changes in sleep deprivation and fatigue, and is affected by drug use and age of subjects12,13. The PVT is a seemingly simple procedure in which a subject briefly touches a screen when a stimulus (typically an LED number display) appears randomly in time, typically after 2 - 10 s. In the human version, the number display is incremented in ms and stopped when the screen is touched, thus indicating the subject&#39;s reaction time (RT). Decreases in vigilance are indicated by 1) slowed reaction times, 2) an increase in lapses (termed &#34;errors of omission&#34; in the human literature, and usually defined as RTs that are &#62; 500 ms in length), and 3) an increase in premature responding (termed &#34;errors of commission&#34; or &#34;false starts&#34; in the human literature). Other measures can also be obtained with the PVT for examining such variables as gender and age differences; for a review of these measures, see Basner and Dinges4. Finally, the PVT has been employed in the general area of human risk assessment, and has been successfully used under a wide range of operational areas that include the military, aviation and railway industries, first responders, and extreme environments such as NASA&#39;s Extreme Environment Missions Operations (NEEMO), the international Mars500 Project14, and on the International Space Station (ISS). On the ISS, the PVT is called the &#34;Reaction Self-Test&#34; and is employed to provide astronauts with individualized fatigue-related feedback (e.g., changes in RTs or lapses in attention).
The human PVT has been in use for decades, as have rodent versions of simple reaction time tasks (which are somewhat similar). It has been only recently, however, that a direct rodent counterpart to the human PVT has been reported in the literature. Christie and colleagues described a version of the human PVT for rats, and reported decreases in vigilance following sleep deprivation15,16. Additional recent studies have reported versions of the rPVT17-19. These reports have described changes in sustained attention following various sleep deprivation techniques; however, the data from these studies have also reported high levels of premature responding (e.g., in some cases, more than 40% of the total number of responses); such performances are quite unlike any PVT performances with humans. Such a large difference in rodent vs. human performances are likely due to differences in specific parameters employed in the human vs. the rodent versions of the PVT; for example, the Christie et al. study employed a randomly varying 3 - 7 s foreperiod, while a human PVT normally employs a 2 - 10 s foreperiod (although see Basner et al.5 for a 3-min version of the human PVT that uses a 1 - 4 s foreperiod). The use of relatively short foreperiod values can often result in animals &#34;timing&#34; their responses, and thus can promote, via accidental reinforcement, increased numbers of premature responses, as have been reported in the current rodent rPVT studies.
The version of the rPVT described here is based on our previously published article20, and provides a detailed description of the techniques and procedures involved. It differs from previously published versions of the rPVT in the following respects: 1) rats were trained with variable foreperiod values of 3 - 10 s, and 2) rats had to respond quickly, since only responses within a short response window (also termed a &#34;limited hold&#34;) following stimulus onset were reinforced (1.5 s in the present study; 3.0 s in the previous published versions of the rPVT). Using these modifications as well as brief timeouts for incorrect responding resulted in greater levels of stimulus control, as indicated by significant improvements in accuracy and reduced levels of premature responding. The present report also describes predictable changes in performance variables (e.g., lapses in attention, RTs) that parallel those seen in humans when examining vigilance decrements21, and when examining other performance measures including the human &#34;time on task&#34; effect and the response-stimulus interval (RSI) effect that is observed in the human PVT22.
The final version of the rPVT described here begins by turning on a house light (see Figure 1). After a variable interval (foreperiod) of 3 - 10 s elapses, the nose-poke key is illuminated for a maximum of 1.5 s. (To insure an equal distribution of foreperiods durations, values are randomly generated without replacement from a list of 36 possible values that range from 3 to 10 s, based on 200 ms increments.) Illumination of the nosepoke key is the signal for an animal to respond, and a response that occurs between 150 to 1,500 ms following the light onset is reinforced with a 45-mg pellet. After a reinforced response, both the nose-poke key light and the house light are turned off and a 1 s inter-trial interval (ITI; house light off) ensues. Nose-pokes at before light onset produce an 8 s timeout (TO) from the experimental contingencies that is signaled by extinguishing the house light. If no responses occur within the 1.5 s response window, both the nosepoke light and house light are turned off, and a 1 s ITI ensues. The next scheduled foreperiod value for the subsequent trial begins after either the 1 s ITI or the 8 s TO, whichever occurred during the prior trial. Sessions are conducted daily (5 days/week), normally consist of about 200 trials, and end after 30 min. This results with each trial having a duration of about 7.5 s, on average.
Shaping stable baseline performance on the rPVT is accomplished by 1) initially adapting a rat to take food pellets out of the food tray in the chamber, 2) hand-shaping a rat to respond on a nose poke key by reinforcing successive approximations to the final nose poke response, and 3) conducting daily sessions where the parameters of the rPVT procedure (i.e., foreperiod, ITI, TO, and key-illumination times) are gradually adjusted over a session, depending on how well each rat is performing during each session (described in detail below).

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the rodent psychomotor vigilance test (rpvt): a method for assessing neurobehavioral performance in rats and mice

The human Psychomotor Vigilance Test (PVT) is a widely used procedure for measuring changes in fatigue and sustained attention. The present article describes a rodent version of the PVT&#8212;termed the &#34;rPVT&#34;&#8212;that measures similar aspects of attention (i.e., performance accuracy, motor speed, premature responding, and lapses in attention). Data are presented that demonstrate both the short- and long-term usefulness of the rPVT when employed with laboratory rats. Rats easily learn the rPVT, and learning to perform the basic procedure takes less than two weeks of training. Once acquired, rat performances in the rPVT show a high degree of similarity to these same performance measures in the human PVT, including similarities in, lapses in attention, reaction times, vigilance decrements across session time (i.e., the human &#34;time-on-task&#34; effects), and the response-stimulus interval (RSI) effect described for humans. Thus the rPVT can be an extremely valuable tool for assessing the effects of a wide range of variables on sustained attention quite similar to human PVT performances, and thus can be useful for developing novel treatments for neurobehavioral dysfunctions.

Baseline Rat rPVT Performances
With the parameters detailed here, 86.7% of the 122 male rats reached the final rPVT parameters within an average of 9.0 (SD = 10.13; n = 122) computer-automated training sessions (described in 4.1 - 4.9 rPVT Training; in our experience, only approximately 2% of rats will not acquire the rPVT). Using the current methodology, rats averaged 73.4% correct responding, 18.6% lapses in attention, and 10.6% ...

Watch this Scientific Journal Video about The Rodent Psychomotor Vigilance Test rPVT: A Method for Assessing Neurobehavioral Performance in Rats and Mice at JoVE.com

The Rodent Psychomotor Vigilance Test rPVT: A Method for Assessing Neurobehavioral Performance in Rats and Mice

A rat version of the human Psychomotor Vigilance Test (PVT) is described that measures aspects of attention similar to those measured with the human PVT, including aspects of human vigilance such as performance accuracy, motor speed, premature responding, and lapses in attention.

The Rodent Psychomotor Vigilance Test (rPVT): A Method for Assessing Neurobehavioral Performance in Rats and Mice

The human Psychomotor Vigilance Test (PVT) is a widely used procedure for measuring changes in fatigue and sustained attention. The present article ...

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12.0K Views.  The Johns Hopkins University School of Medicine. A rat version of the human Psychomotor Vigilance Test (PVT) is described that measures aspects of attention similar to those measured with the human PVT, including aspects of human vigilance such as performance accuracy, motor speed, premature responding, and lapses in attention.

Video: The Rodent Psychomotor Vigilance Test rPVT: A Method for Assessing Neurobehavioral Performance in Rats and Mice

The Successive Alleys Test of Anxiety in Mice and Rats

The plus-maze was derived from the early work of Montgomery. He observed that rats tended to avoid the open arms of a maze, preferring the enclosed ones. Handley, Mithani and File et al. performed the first studies on the plus-maze design we use today, and in 1987 Lister published a design for use with mice. 
Time spent on, and entries into, the open arms are an index of anxiety; the lower these indices, the more anxious the mouse is. Alternatively, a mouse that spends most of its time in the closed arms is classed as anxious. 
One of the problems of the plus-maze is that, while time spent on, and entries into, the open arms is a fairly unambiguous measure of anxiety, time in the central area is more difficult to interpret, although time spent here has been classified as &#x201C;decision making&#x201D;. In many tests central area time is a considerable part of the total test time.
Shepherd et al. produced an ingenious design to eliminate the central area, which they called the &#x201C;zero maze&#x201D;. However, although used by several groups, it has never been as widely adopted as the plus-maze. 
In the present article I describe a modification of the plus-maze design that not only eliminates the central area but also incorporates elements from other anxiety tests, such as the light-dark box and emergence tests. It is a linear series of four alleys, each having increasing anxiogenic properties. It has given similar results to the plus-maze in general. Although it may not be more sensitive than the plus-maze (more data is needed before a firm conclusion can be reached on this point), it provides a useful confirmation of plus-maze results which would be useful when, for example, only a single example of a mutant mouse was available, as, for example, in ENU-based mutagenesis programs.

The plus-maze measures anxiety-like behaviour in rodents. There are two opposite closed and two opposite open arms; anxious rodents avoid the open arms. The central area is neither completely open nor closed, so time spent here is ambiguous and difficult to interpret. Here a modification of the plus-maze protocol eliminating this area is described.

The plus-maze was derived from the early work of Montgomery. He observed that rats tended to avoid the open arms of a maze, preferring the enclosed ones.  ...

Contextual and Cued Fear Conditioning Test Using a Video Analyzing System in Mice

The contextual and cued fear conditioning test is one of the behavioral tests that assesses the ability of mice to learn and remember an association between environmental cues and aversive experiences. In this test, mice are placed into a conditioning chamber and are given parings of a conditioned stimulus (an auditory cue) and an aversive unconditioned stimulus (an electric footshock). After a delay time, the mice are exposed to the same conditioning chamber and a differently shaped chamber with presentation of the auditory cue. Freezing behavior during the test is measured as an index of fear memory. To analyze the behavior automatically, we have developed a video analyzing system using the ImageFZ application software program, which is available as a free download at http://www.mouse-phenotype.org/. Here, to show the details of our protocol, we demonstrate our procedure for the contextual and cued fear conditioning test in C57BL/6J mice using the ImageFZ system. In addition, we validated our protocol and the video analyzing system performance by comparing freezing time measured by the ImageFZ system or a photobeam-based computer measurement system with that scored by a human observer. As shown in our representative results, the data obtained by ImageFZ were similar to those analyzed by a human observer, indicating that the behavioral analysis using the ImageFZ system is highly reliable. The present movie article provides detailed information regarding the test procedures and will promote understanding of the experimental situation.

This article presents a protocol for a contextual and cued fear conditioning test using a video analyzing system to assess fear learning and memory in mice.

The contextual and cued fear conditioning test is one of the behavioral tests that assesses the ability of mice to learn and remember an association ...

Assessing Functional Performance in the Mdx Mouse Model

Duchenne muscular dystrophy (DMD) is a severe and progressive muscle wasting disorder for which no cure is available. Nevertheless, several potential pharmaceutical compounds and gene therapy approaches have progressed into clinical trials. With improvement in muscle function being the most important end point in these trials, a lot of emphasis has been placed on setting up reliable, reproducible, and easy to perform functional tests to pre clinically assess muscle function, strength, condition, and coordination in the mdx mouse model for DMD. Both invasive and noninvasive tests are available. Tests that do not exacerbate the disease can be used to determine the natural history of the disease and the effects of therapeutic interventions (e.g. forelimb grip strength test, two different hanging tests using either a wire or a grid and rotarod running). Alternatively, forced treadmill running can be used to enhance disease progression and/or assess protective effects of therapeutic interventions on disease pathology. We here describe how to perform these most commonly used functional tests in a reliable and reproducible manner. Using these protocols based on standard operating procedures enables comparison of data between different laboratories.

Assessing Functional Performance in the Mdx Mouse Model

The primary outcome measure in clinical trials for neuromuscular disorders is generally improved muscle function. Therefore, assessing the effect of potential therapeutic compounds on muscle performance pre clinically in mouse models is of great importance. We here describe several functional tests to address this.

Duchenne muscular dystrophy (DMD) is a severe and progressive muscle wasting disorder for which no cure is available. Nevertheless, several potential ...

Operant Procedures for Assessing Behavioral Flexibility in Rats

Executive functions consist of multiple high-level cognitive processes that drive rule generation and behavioral selection. An emergent property of these processes is the ability to adjust behavior in response to changes in one&#8217;s environment (i.e., behavioral flexibility). These processes are essential to normal human behavior, and may be disrupted in diverse neuropsychiatric conditions, including schizophrenia, alcoholism, depression, stroke, and Alzheimer&#8217;s disease. Understanding of the neurobiology of executive functions has been greatly advanced by the availability of animal tasks for assessing discrete components of behavioral flexibility, particularly strategy shifting and reversal learning. While several types of tasks have been developed, most are non-automated, labor intensive, and allow testing of only one animal at a time. The recent development of automated, operant-based tasks for assessing behavioral flexibility streamlines testing, standardizes stimulus presentation and data recording, and dramatically improves throughput. Here, we describe automated strategy shifting and reversal tasks, using operant chambers controlled by custom written software programs. Using these tasks, we have shown that the medial prefrontal cortex governs strategy shifting but not reversal learning in the rat, similar to the dissociation observed in humans. Moreover, animals with a neonatal hippocampal lesion, a neurodevelopmental model of schizophrenia, are selectively impaired on the strategy shifting task but not the reversal task. The strategy shifting task also allows the identification of separate types of performance errors, each of which is attributable to distinct neural substrates. The availability of these automated tasks, and the evidence supporting the dissociable contributions of separate prefrontal areas, makes them particularly well-suited assays for the investigation of basic neurobiological processes as well as drug discovery and screening in disease models.

The ability to assess executive functions such as behavioral flexibility in rats is useful for investigating the neurobiology of cognition in both intact animals and disease models. Here we describe automated tasks for assessing strategy shifting and reversal learning, which are particularly sensitive to disruptions in prefrontal cortical networks.

Executive functions consist of multiple high-level cognitive processes that drive rule generation and behavioral selection. An emergent property of these ...

The Modified Hole Board - Measuring Behavior, Cognition and Social Interaction in Mice and Rats

This protocol describes the modified hole board (mHB), which combines features from a traditional hole board and open field and is designed to measure multiple dimensions of unconditioned behavior in small laboratory mammals (e.g., mice, rats, tree shrews and small primates). This paradigm is a valuable alternative for the use of a behavioral test battery, since a broad behavioral spectrum of an animal&#8217;s behavioral profile can be investigated in one single test.
The apparatus consists of a box, representing the &#8216;protected&#8217; area, separated from a group compartment. A board, on which small cylinders are staggered in three lines, is placed in the center of the box, representing the &#8216;unprotected&#8217; area of the set-up. The cognitive abilities of the animals can be measured by baiting some cylinders on the board and measuring the working and reference memory. Other unconditioned behavior, such as activity-related-, anxiety-related- and social behavior, can be observed using this paradigm. Behavioral flexibility and the ability to habituate to a novel environment can additionally be observed by subjecting the animals to multiple trials in the mHB, revealing insight into the animals&#8217; adaptive capacities.
Due to testing order effects in a behavioral test battery, na&#239;ve animals should be used for each individual experiment. By testing multiple behavioral dimensions in a single paradigm and thereby circumventing this issue, the number of experimental animals used is reduced. Furthermore, by avoiding social isolation during testing and without the need to food deprive the animals, the mHB represents a behavioral test system, inducing if any, very low amount of stress.

This protocol describes the modified hole board, which is a behavioral test set-up that comprises the characteristics of an open field and a traditional hole board. This set-up enables the differential analysis of unconditioned behavior of small laboratory mammals as well as the analysis of cognitive abilities.

This protocol describes the modified hole board (mHB), which combines features from a traditional hole board and open field and is designed to measure ...

A Method to Test the Effect of Environmental Cues on Mating Behavior in Drosophila melanogaster

An individual's sexual drive is influenced by genotype, experience and environmental conditions. How these factors interact to modulate sexual behaviors remains poorly understood. In Drosophila melanogaster, environmental cues, such as food availability, affect mating activity offering a tractable system to investigate the mechanisms modulating sexual behavior. In D. melanogaster, environmental cues are often sensed via the chemosensory gustatory and olfactory systems. Here, we present a method to test the effect of environmental chemical cues on mating behavior. The assay consists of a small mating arena containing food medium and a mating couple. The mating frequency for each couple is continuously monitored for 24 h. Here we present the applicability of this assay to test environmental compounds from an external source through a pressurized air system as well as manipulation of the environmental components directly in the mating arena. The use of a pressurized air system is especially useful to test the effect of very volatile compounds, while manipulating components directly in the mating arena can be of value to ascertain a compound's presence. This assay can be adapted to answer questions about the influence of genetic and environmental cues on mating behavior and fecundity as well as other male and female reproductive behaviors.

A Method to Test the Effect of Environmental Cues on Mating Behavior in Drosophila melanogaster

We demonstrate an assay to analyze the environmental and genetic cues that influence mating behavior in the fruit fly Drosophila melanogaster.

An individual's sexual drive is influenced by genotype, experience and environmental conditions. How these factors interact to modulate sexual behaviors ...

Novel Object Recognition Test for the Investigation of Learning and Memory in Mice

The object recognition test (ORT) is a commonly used behavioral assay for the investigation of various aspects of learning and memory in mice. The ORT is fairly simple and can be completed over 3 days: habituation day, training day, and testing day. During training, the mouse is allowed to explore 2 identical objects. On test day, one of the training objects is replaced with a novel object. Because mice have an innate preference for novelty, if the mouse recognizes the familiar object, it will spend most of its time at the novel object. Due to this innate preference, there is no need for positive or negative reinforcement or long training schedules. Additionally, the ORT can also be modified for numerous applications. The retention interval can be shortened to examine short-term memory, or lengthened to probe long-term memory. Pharmacological intervention can be used at various times prior to training, after training, or prior to recall to investigate different phases of learning (i.e., acquisition, early or late consolidation, or recall). Overall, the ORT is a relatively low-stress, efficient test for memory in mice, and is appropriate for the detection of neuropsychological changes following pharmacological, biological, or genetic manipulations.

The object recognition test (ORT) is a simple and efficient assay for evaluating learning and memory in mice. The methodology is described below.

The object recognition test (ORT) is a commonly used behavioral assay for the investigation of various aspects of learning and memory in mice. The ORT is ...

The Knob Supination Task: A Semi-automated Method for Assessing Forelimb Function in Rats

Tasks that accurately measure dexterity in animal models are critical to understand hand function. Current rat behavioral tasks that measure dexterity largely use video analysis of reaching or food manipulation. While these tasks are easy to implement and are robust across disease models, they are subjective and laborious for the experimenter. Automating traditional tasks or creating new automated tasks can make the tasks more efficient, objective, and quantitative. Since rats are less dexterous than primates, central nervous system (CNS) injury produces more subtle deficits in dexterity, however, supination is highly affected in rodents and crucial to hand function in primates. Therefore, we designed a semi-automated task that measures forelimb supination in rats. Rats are trained to reach and grasp a knob-shaped manipulandum and turn the manipulandum in supination to receive a reward. Rats can acquire the skill within 20 &plusmn; 5 days. While the early part of training is highly supervised, much of the training is done without direct supervision. The task reliably and reproducibly captures subtle deficits after injury and shows functional recovery that accurately reflects clinical recovery curves. Analysis of data is performed by specialized software through a graphical user interface that is designed to be intuitive. We also give solutions to common problems encountered during training, and show that minor corrections to behavior early in training produce reliable acquisition of supination. Thus, the knob supination task provides efficient and quantitative evaluation of a critical movement for dexterity in rats.

This manuscript describes a semi-automated task that quantifies supination in rats. Rats reach, grasp, and supinate a spherical manipulandum. The rat is rewarded with a pellet if the turn angle exceeds a criterion set by the user. This task increases throughput, sensitivity to injury, and objectivity compared to traditional tasks.

Tasks that accurately measure dexterity in animal models are critical to understand hand function. Current rat behavioral tasks that measure dexterity ...

A New Method for Inducing a Depression-Like Behavior in Rats

Contagious depression is a phenomenon that is yet to be fully recognized and this stems from insufficient material on the subject. At the moment, there is no existing format for studying the mechanism of action, prevention, containment, and treatment of contagious depression. The purpose of this study, therefore, was to establish the first animal model of contagious depression.
Healthy rats can contract depressive behaviors if exposed to depressed rats. Depression is induced in rats by subjecting them to several manipulations of chronic unpredictable stress (CUS) over 5 weeks, as described in the protocol. A successful sucrose preference test confirmed the development of depression in the rats. The CUS-exposed rats were then caged with na&#239;ve rats from the contagion group (1 na&#239;ve rat/2 depressed rats in a cage) for an additional 5 weeks. 30 social groups were created from the combination of CUS-exposed rats and na&#239;ve rats.
This proposed depression-contagion protocol in animals consists mainly of cohabiting CUS-exposed and healthy rats for 5 weeks. To ensure that this method works, a series of tests are carried out - first, the sucrose preference test upon inducing depression to rats, then, the sucrose preference test, alongside the open field and forced-swim tests at the end of the cohabitation period. Throughout the experiment, rats are given tags and are always returned to their cages after each test.
A few limitations to this method are the weak differences recorded between the experimental and control groups in the sucrose preference test and the irreversible traumatic outcome of the forced swim test. These may be worth considering for suitability before any future application of the protocol. Nonetheless, following the experiment, na&#239;ve rats developed contagion depression after 5 weeks of sharing the same cage with the CUS-exposed rats.

This protocol describes a new model by which healthy rats could contract depression over a given time periodthrough contagion by exposure to chronic unpredictable stressed (CUS) rats.

Contagious depression is a phenomenon that is yet to be fully recognized and this stems from insufficient material on the subject. At the moment, there is ...

Assessing the Coherence of Parents' Short Narratives Regarding their Child Using the Five-Minute Speech Sample Procedure

Valid and efficient measures for assessing the quality of parent-child relationships are needed to facilitate research and evidence-based practice with parents. This paper focuses on such a method, namely Five-Minute Speech Sample-Coherence (FMSS-Coherence). In this method, a parent is asked to speak for five uninterrupted minutes about her/his child and their relationship. The resulted narrative is coded for coherence, namely the extent to which the parent provides&#160;in the narrative&#160;a clear, consistent, multidimensional and well-supported portrayal of the child. FMSS-Coherence is based on attachment research that shows that the coherence of parents&#8217; narratives is indicative of the quality of the parent-child relationship and child adjustment. It overcomes the limitations of attachment narrative measures which are typically labor intensive. FMSS-Coherence is less nuanced than extant attachment narrative measures. Yet, studies of families from different cultural backgrounds, across different child ages and in the context of typically developing children as well as children with special needs suggest that coherence can be reliably evaluated using the FMSS procedure. Furthermore, parents&#8217; FMSS-Coherence is associated with parenting quality and children&#8217;s socio-emotional adjustment. Thus, it holds promise for researchers and practitioners who seek a relatively time- and cost-effective method for assessing the coherence of parents&#8217; narratives regarding their child.

This paper introduces a method for assessing the coherence of parents' short narratives regarding their child and their relationship using the five-minute speech sample procedure.

Valid and efficient measures for assessing the quality of parent-child relationships are needed to facilitate research and evidence-based practice with ...