Name: key elements of photo attraction bioassay for insect studies or monitoring programs
Uploaded: 2018-07-26T12:30:00
Description: Watch this Scientific Journal Video about Key Elements of Photo Attraction Bioassay for Insect Studies or Monitoring Programs at JoVE.com

1. Bioassay Components
<ol>
	<li>Terrestrial arena construction
	<ol>
		<li>Use metal flashing material strips of 2.54 cm length. Bend each strip into a half circle having a diameter of 15.24 cm (Figure 1).</li>
		<li>Connect the ends of each half circle and form a cloverleaf shape from the four pieces. Connect a locking nut and a #10 machine screw to the ends of each half circle to hold them together.</li>
		<li>Drill a hole at the midpoint of each semicircle 0.79 cm from...

<ol>
	<li>Briscoe, A. D., Chittka, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+evolution+of+color+vision+in+insects.">The evolution of color vision in insects.</a> Annu. Rev. Entomol. 46, 471-510 (2001).</li><li>Srinivasan, M. V., Chahl, J. S., Nagle, M. G., Zhang, S. W., Srinivasan, M. V., Venkatesh, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Embodying+natural+vision+into+machines.">Embodying natural vision into machines.</a> From living eyes to seeing machines. , 249-265 (1997).</li><li>Srinivasan, M., Moore, R. J. D., Thurrowgood, S., Soccol, D., Bland, D., Barth, F. G., Humphrey, J. A. C., Srinivasan, M. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+Biology+to+engineering:+insect+vision+and+applications+to+robotics.">From Biology to engineering: insect vision and applications to robotics.</a> Frontiers in sensing. , 19-39 (2012).</li><li>Allan, S. A., Day, J. F., Edman, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visual+ecology+of+biting+flies.">Visual ecology of biting flies.</a> Annu.Rev. Entomol. 32, 297-316 (1987).</li><li>Brown, A. W. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studies+of+the+responses+of+the+female+Aedes+mosquito+Part+V.+The+role+of+visual+factors.">Studies of the responses of the female Aedes mosquito Part V. The role of visual factors.</a> Bull. Entomol. Res. 44, 567-574 (1953).</li><li>Brown, A. W. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Studies+on+the+responses+of+the+female+Aedes+mosquito+Part+VI.+The+attractiveness+of+coloured+cloths+and+Canadian+species.">Studies on the responses of the female Aedes mosquito Part VI. The attractiveness of coloured cloths and Canadian species.</a> Bull. Entomol. Res. 45, 67-78 (1954).</li><li>Snyder, D., Cernicchiaro, N., Cohnstaedt, L. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sugar-feeding+status+alters+biting+midge+photoattraction.">Sugar-feeding status alters biting midge photoattraction.</a> Med. Vet. Entomol. 30, 31-38 (2016).</li><li>Menzel, R., Shmida, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+ecology+of+flower+colours+and+the+natural+colour+vision+of+insect+pollinators:+The+Israeli+flora+as+a+study+case.">The ecology of flower colours and the natural colour vision of insect pollinators: The Israeli flora as a study case.</a> Biological Reviews. 68, 81-120 (1993).</li><li>Walker, W. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Responses+of+selected+thysanoptera+to+colored+surfaces.">Responses of selected thysanoptera to colored surfaces.</a> Environ. Entomol. 3, 295-304 (1974).</li><li>Lelito, J. P., Fraser, I., Mastro, V. C., Tumlinson, J. H., Baker, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+visual-cue-based+stickytraps+for+monitoring+of+emerald+ash+borers,+Agrilus+planipennis+(Col.,+Buprestidae).">Novel visual-cue-based stickytraps for monitoring of emerald ash borers, Agrilus planipennis (Col., Buprestidae).</a> J. Appl. Entomol. 132, 668-674 (2008).</li><li>Diclaro, J. W., Cohnstaedt, L. W., Pereira, R. M., Allan, S. A., Koehler, P. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Behavioral+and+Physiological+Response+of+Musca+domestica+to+Colored+Visual+Targets.">Behavioral and Physiological Response of Musca domestica to Colored Visual Targets.</a> J. Med. Entomol. 49 (1), 94D100 (2012).</li><li>Steverding, D., Troscianko, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+role+of+blue+shadows+in+the+visual+behaviour+of+tsetse+flies.">On the role of blue shadows in the visual behaviour of tsetse flies.</a> Proc. R. Soc. Lond. B. 271, 16-17 (2004).</li><li>Cohnstaedt, L. W., Gillen, J. I., Munstermann, L. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light-emitting+diode+technology+improves+insect+trapping.">Light-emitting diode technology improves insect trapping.</a> J. Am. Mosq. Control Assoc. 24, 331-334 (2008).</li><li>Duehl, A. J., Cohnstaedt, L. W., Arbogast, R. T., Teal, P. E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluating+light+attraction+to+increase+trap+efficiency+for+Tribolium+castaneum+(Coleoptera:+Tenebrionidae).">Evaluating light attraction to increase trap efficiency for Tribolium castaneum (Coleoptera: Tenebrionidae).</a> J. Economic Entomol. 104, 1430-1435 (2011).</li><li>Schmid, R. B., Snyder, D., Cohnstaedt, L. W., McCornack, B. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hessian+Fly+(Diptera:+Cecidomyiidae)+Attraction+to+Different+Wavelengths+and+Intensities+of+Light-EmittingDiodes+in+the+Laboratory.">Hessian Fly (Diptera: Cecidomyiidae) Attraction to Different Wavelengths and Intensities of Light-EmittingDiodes in the Laboratory.</a> Environ. Entomol. 46 (4), 895-900 (2017).</li><li>Cohnstaedt, L. W., Snyder, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Design+features+of+a+proposed+insecticidal+sugar+trap+for+biting+midges.">Design features of a proposed insecticidal sugar trap for biting midges.</a> Vet. Ital. 52 (3-4), 265-269 (2016).</li></ol>

Photo-attraction bioassays are an important tool to determine the optimal attractive color(s) and minimize the options for field trials of these colors. However, several factors must be considered when optimizing the bioassay for a specific insect including: Single Light vs. competitive light experiments, brightness, optimal spectral range, ambient light interference, state of the insects, and natural behaviors that may limit the possible responses.
Most insects have some phototaxis, ...

Almost all entomological surveillance depends on olfaction or visual attractants and often both. Volatile olfactory attractants may disperse throughout the environment resulting in a large attractive area. However, visual attractants may have a more limited range because of the invertebrate compound eye resolving images1,2,3. Therefore, visual attractants must be optimized to the insect of interest to maximize attraction and the trap designed to take advantage of the target insect&#39;s natural behaviors.
Visual attraction is based on wavelengths from the sun or other sources of light that are absorbed or reflected by an object&#39;s surface; organisms view this absorption/refraction of wavelengths as color. Insect vision has been found to include blue, green, and ultraviolet (UV) wavelengths1. Insects use their vision to aid in finding mates, food, and shelter4. Insects can visually define object sizes, colors, shapes, movements and contrasts5,6. Nocturnally active insects are generally attracted to light of differing contrast and intensity4, whereas diurnal insects can resolve colors and images, in addition to contrast because of greater photon availability during the day. Monitoring traps use the insect&#39;s visual cues to their advantage to optimize attraction and capture7.
The most common method of evaluating photo-attraction was observation of insect movement towards various colored shapes such as flowers8&#160;or objects (such as sticky cards9,10). Visual bioassays using colonized insects can help identify the optimal range of wavelengths and/or intensities, which reduces the number of field trials. Visual bioassays such as the &#34;Two-Sided Light Tunnel&#34; were designed for testing flies11. The problem with two sided light tunnels are that they do not account for insects that are not collected. Most insects will get stuck on internal corners and along edges in arenas. Also only two colors can be tested at one time. Other assays include the methods of Steverding &#38; Troscianko (2004)12, which narrowed tsetse fly attraction to broad bands (&#177;50 nm) of light colors. Light emitting diodes (LEDs) have been incorporated into traps to improve insect attraction by optimizing the wavelengths of emitted light1,13,14. Optimizing the visual attraction of these traps or monitoring devices will improve insect collection efficiency by using the insect&#39;s innate behaviors to lure insects. In this way, bioassay results are used to optimize existing trapping technology. The &#34;Terrestrial Arthropod Trap&#34; that improved the industry standard dome-type trap for red flour beetle surveillance (US patent# US8276314B2)) and the &#34;Method and Compositions for Improved Light Traps&#34; that incorporated of light emitting diodes into aerial insect traps (US patent# US2009/0025275A1). The two patents use LED technology that was optimized using the bioassay results to significantly improve insect traps.
This study describes a photo attraction bioassay arena and methods that allow investigators to evaluate the insect response to narrow wavelengths as a competitive or single attractive color. Equipment and experimental modifications are presented for nocturnal, diurnal, terrestrial, and aerial insects.

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key elements of photo attraction bioassay for insect studies or monitoring programs

Optimized visual attractants will increase insect trapping efficiency by using the target insect&#39;s innate behaviors (positive photo-taxis) as a means to lure the insect into a population control or monitoring trap. Light emitting diodes (LEDs) have created customizable lighting options with specific wavelengths (colors), intensities, and bandwidths, all of which can be customized to the target insects. Photo-attraction behavioral bioassays can use LEDs to optimize the attractive color(s) for an insect species down to specific life history stages or behaviors (mating, feeding, or seeking shelter). Researchers must then confirm the bioassay results in the field and understand the limited attractive distance of the visual attractants.
The cloverleaf bioassay arena is a flexible method to assess photo attraction while also assessing a range of natural insect behaviors such as escape and feeding responses. The arena can be used for terrestrial or aerial insect experiments, as well as diurnal, and nocturnal insects. Data collection techniques with the arena are videotaping, counting contact with the lights, or physically collecting the insects as they are attracted towards the lights. The assay accounts for insects that make no-choice and the arenas can be single (noncompetitive) color or multiple (competitive) colors. The cloverleaf design causes insects with strong thigmotaxis to return to the center of the arena where they can view all the options in a competitive LED tests. The cloverleaf arena presented here has been used with mosquitoes, bed bugs, Hessian fly, house flies, biting midges, red flour beetles, and psocids. Bioassays are used to develop accurate and effective insect traps to guide the development and optimization of insect traps used to monitor pest population fluctuations for disease vector risk assessments, the introduction of invasive species, and/or be used for population suppression.

The terrestrial arena has been used to improve pest monitoring traps for red flour beetles14 and the aerial arenas for hessian flies15 and biting midges7. Although the cloverleaf arenas were similar, the conditions for each insect species were different and accommodated the evaluation of nocturnal or diurnal insects that can crawl or fly. More importantly these lab studies translated into field applications for monito...

Watch this Scientific Journal Video about Key Elements of Photo Attraction Bioassay for Insect Studies or Monitoring Programs at JoVE.com

Key Elements of Photo Attraction Bioassay for Insect Studies or Monitoring Programs

Photo-attraction bioassay arenas are used to determine the optimal light color(s) to maximize insect attraction; however bioassays and methods are specific to target insect behaviors and habitats. Customizable equipment and modifications are explained for nocturnal or diurnal and terrestrial or aerial insects.

Optimized visual attractants will increase insect trapping efficiency by using the target insect&#39;s innate behaviors (positive photo-taxis) as a means ...

This method can help answer key questions in insect surveillance and control, by improving the attraction of existing traps and incorporating colors or lights into the design of future monitoring and control traps. The main advantage of this technique is the initial evaluation of attractive colors and insect behaviors in the lab, prior to the costly and time consuming tests in the field. Insects have innate behaviors or instincts that should be used to make monitoring and trapping more effective.The bioassay arena is designed to be a flexible method to evaluate behaviors in any insect species, prior to field trials. This protocol uses an aerial arena, but a terrestrial arena design is also available. The critical difference between the aerial and terrestrial arena's is the use of vertical space, which changes the size of the arena.When selecting an arena type for an experiment consider the insect species being studied. The aerial arena has the ability to capture insects in a collection container, whereas the terrestrial arena is a two dimensional object and really is designed for recording visits to the lights. To begin, disassemble and clean the aerial arena with an odorless, non abrasive soap and warm water.Then dry the arena and allow it to finish air drying. Before each experiment record the pertinent environmental conditions, and monitor any trends that occur from experiment to experiment. First, use four supports and black linen cloth to set up a pedestal.Then place the arena baseplate on top of the pedestal and assemble each piece of the arena on the baseplate. Next, place the cloverleaf arena around the central release point in the baseplate. Then install the LEDs into the LED holders of the four collection containers, and set up the electrical equipment to control the lights.To prepare the arena for a competitive experiment, position LED lights with distinct characteristics on each cloverleaf. The arena set up is the most important and critical factor, because simple changes in the arena can alter the insect's behaviors. Therefore, many factors can be changed or altered to address insect behaviors, such as photo attraction.Behaviors with feeding, so blood fed, or sugar fed or starved. Different life history stages or different physiological responses. Next, to control for potential effect of light interference or environmental preferences, rotate the light positions after every replicate.Refer to the text protocol for further information on filming devices. First place the clear lid over the arena, parallel to the baseplate. Then introduce immobilized midges to the arena.After the experimental period record the pertinent environmental conditions. Finally, after euthanizing the midges count the responders in each collection container. In this study the movement of red flower beetles was evaluated in a competitive style terrestrial arena for five minutes, and filmed with an infrared camera.Test colors included blue, and three wavelengths of UV light. The trial data indicated that the beetles were most attracted to near UV light with a wavelength of 390 nanometers. The movement of Hessian flies was also evaluated in a competitive style aerial arena with a diurnal setting.The lights were most attracted to lights in green wavelengths with high intensities. Female flies preferred the green spectra of 502 and 525 nanometers. While both sexes preferred the high intensity 16 watts per square meter light.Biting midges were also tested in the aerial arena under nocturnal conditions, to determine optimal attractive colors. The highest proportions of midges were attracted to UV light, with the brightest lights being the most attractive. Once mastered, the photo attraction bioassay can be used to rapidly assess insect behavior, prior to costly and labor intensive field trials.

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Research

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Behavior

A Procedure to Study the Effect of Prolonged Food Restriction on Heroin Seeking in Abstinent Rats

In human drug addicts, exposure to drug-associated cues or environments that were previously associated with drug taking can trigger relapse during abstinence. Moreover, various environmental challenges can exacerbate this effect, as well as increase ongoing drug intake.
The procedure we describe here highlights the impact of a common environmental challenge, food restriction, on drug craving that is expressed as an augmentation of drug seeking in abstinent rats.
Rats are implanted with chronic intravenous i.v. catheters, and then trained to press a lever for i.v. heroin over a period of 10-12 days. Following the heroin self-administration phase the rats are removed from the operant conditioning chambers and housed in the animal care facility for a period of at least 14 days. While one group is maintained under unrestricted access to food (sated group), a second group (FDR group) is exposed to a mild food restriction regimen that results in their body weights maintained at 90% of their nonrestricted body weight. On day 14 of food restriction the rats are transferred back to the drug-training environment, and a drug-seeking test is run under extinction conditions (i.e.&#160;lever presses do not result in heroin delivery).
The procedure presented here results in a highly robust augmentation of heroin seeking on test day in the food restricted rats. In addition, compared to the acute food deprivation manipulations we have used before, the current procedure is a more clinically relevant model for the impact of caloric restriction on drug seeking. Moreover, it might be closer to the human condition as the rats are not required to go through an extinction-training phase before the drug-seeking test, which is an integral component of the popular reinstatement procedure.

A procedure that allows a demonstration of robust augmentation of drug seeking in food-restricted rats is described. Following heroin self-administration training, rats go through an abstinence period, in a drug-free environment, during which they are mildly food restricted. Drug seeking is then tested in the drug-associated environment.

In human drug addicts, exposure to drug-associated cues or environments that were previously associated with drug taking can trigger relapse during ...

Early Metamorphic Insertion Technology for Insect Flight Behavior Monitoring

Early Metamorphosis Insertion Technology (EMIT) is a novel methodology for integrating microfabricated neuromuscular recording and actuation platforms on insects during their metamorphic development. Here, the implants are fused within the structure and function of the neuromuscular system as a result of metamorphic tissue remaking. The implants emerge with the insect where the development of tissue around the electronics during pupal development results in a bioelectrically and biomechanically enhanced tissue interface. This relatively more reliable and stable interface would be beneficial for many researchers exploring the neural basis of the insect locomotion with alleviated traumatic effects caused during adult stage insertions. In this article, we implant our electrodes into the indirect flight muscles of Manduca sexta. Located in the dorsal-thorax, these main flight powering dorsoventral and dorsolongitudinal muscles actuate the wings and supply the mechanical power for up and down strokes. Relative contraction of these two muscle groups has been under investigation to explore how the yaw maneuver is neurophysiologically coordinated. To characterize the flight dynamics, insects are often tethered with wires and their flight is recorded with digital cameras. We also developed a novel way to tether Manduca sexta on a magnetically levitating frame where the insect is connected to a commercially available wireless neural amplifier. This set up can be used to limit the degree of freedom to yawing &#8220;only&#8221; while transmitting the related electromyography signals from dorsoventral and dorsolongitudinal muscle groups.

We present a novel surgical procedure to implant electrodes in Manduca sexta during its early metamorphic stages. This technique allows mechanically stable and electrically reliable coupling with the neuromuscular tissue to study flight neurophysiology dynamics. We also present a novel magnetic levitation platform for tethered studies of insect yaw.

Early Metamorphosis Insertion Technology (EMIT) is a novel methodology for integrating microfabricated neuromuscular recording and actuation platforms on ...

A Procedure to Observe Context-induced Renewal of Pavlovian-conditioned Alcohol-seeking Behavior in Rats

Environmental contexts in which drugs of abuse are consumed can trigger craving, a subjective Pavlovian-conditioned response that can facilitate drug-seeking behavior and prompt relapse in abstinent drug users. We have developed a procedure to study the behavioral and neural processes that mediate the impact of context on alcohol-seeking behavior in rats. Following acclimation to the taste and pharmacological effects of 15% ethanol in the home cage, male Long-Evans rats receive Pavlovian discrimination training (PDT) in conditioning chambers. In each daily (Mon-Fri) PDT session, 16 trials each of two different 10 sec auditory conditioned stimuli occur. During one stimulus, the CS+, 0.2 ml of 15% ethanol is delivered into a fluid port for oral consumption. The second stimulus, the CS-, is not paired with ethanol. Across sessions, entries into the fluid port during the CS+ increase, whereas entries during the CS- stabilize at a lower level, indicating that a predictive association between the CS+ and ethanol is acquired. During PDT each chamber is equipped with a specific configuration of visual, olfactory and tactile contextual stimuli. Following PDT, extinction training is conducted in the same chamber that is now equipped with a different configuration of contextual stimuli. The CS+ and CS- are presented as before, but ethanol is withheld, which causes a gradual decline in port entries during the CS+. At test, rats are placed back into the PDT context and presented with the CS+ and CS- as before, but without ethanol. This manipulation triggers a robust and selective increase in the number of port entries made during the alcohol predictive CS+, with no change in responding during the CS-. This effect, referred to as context-induced renewal, illustrates the powerful capacity of contexts associated with alcohol consumption to stimulate alcohol-seeking behavior in response to Pavlovian alcohol cues.

A procedure to study the capacity of an alcohol associated environmental context to trigger the renewal of alcohol-seeking behavior in rats is described.

Environmental contexts in which drugs of abuse are consumed can trigger craving, a subjective Pavlovian-conditioned response that can facilitate ...

Testing for Odor Discrimination and Habituation in Mice

This video demonstrates a technique to establish the presence of a normally functioning olfactory system in a mouse. The test helps determine whether the mouse can discriminate between non-social odors and social odors, whether the mouse habituates to a repeatedly presented odor, and whether the mouse demonstrates dishabituation when presented with a novel odor. Since many social behavior tests measure the experimental animal&#8217;s response to a familiar or novel mouse, false positives can be avoided by establishing that the animals can detect and discriminate between social odors. There are similar considerations in learning tests such as fear conditioning that use odor to create a novel environment or olfactory cues as an associative stimulus. Deficits in the olfactory system would impair the ability to distinguish between contexts and to form an association with an olfactory cue during fear conditioning. 
In the odor habitation/dishabituation test, the mouse is repeatedly presented with several odors. Each odor is presented three times for two minutes. The investigator records the sniffing time directed towards the odor as the measurement of olfactory responsiveness. A typical mouse shows a decrease in response to the odor over repeated presentations (habituation). The experimenter then presents a novel odor that elicits increased sniffing towards the new odor (dishabituation). After repeated presentation of the novel odor the animal again shows habituation. This protocol involves the presentation of water, two or more non-social odors, and two social odors. In addition to reducing experimental confounds, this test can provide information on the function of the olfactory systems of new knockout, knock-in, and conditional knockout mouse lines.

This manuscript describes a protocol to examine the olfactory system of rodents. The olfactory habituation/dishabituation test will allow investigators to determine whether a mouse habituates to a repeatedly presented odor and whether the mouse demonstrates dishabituation when presented a novel odor.

This video demonstrates a technique to establish the presence of a normally functioning olfactory system in a mouse. The test helps determine whether the ...

A Method for Evaluating the Reinforcing Properties of Ethanol in Rats without Water Deprivation, Saccharin Fading or Extended Access Training

Operant oral self-administration methods are commonly used to study the reinforcing properties of ethanol in animals. However, the standard methods require saccharin/sucrose fading, water deprivation and/or extended training to initiate operant responding in rats. This paper describes a novel and efficient method to quickly initiate operant responding for ethanol that is convenient for experimenters and does not require water deprivation or saccharin/sucrose fading, thus eliminating the potential confound of using sweeteners in ethanol operant self-administration studies. With this method, Wistar rats typically acquire and maintain self-administration of a 20% ethanol solution in less than two weeks of training. Furthermore, blood ethanol concentrations and rewards are positively correlated for a 30 min self-administration session. Moreover, naltrexone, an FDA-approved medication for alcohol dependence that has been shown to suppress ethanol self-administration in rodents, dose-dependently decreases alcohol intake and motivation to consume alcohol for rats self-administering 20% ethanol, thus validating the use of this new method to study the reinforcing properties of alcohol in rats.

This protocol describes a novel and efficient method to quickly initiate operant responding for ethanol in rats that, contrary to standard methods, does not require water deprivation or saccharin/sucrose fading to initiate responding.

Operant oral self-administration methods are commonly used to study the reinforcing properties of ethanol in animals. However, the standard methods ...

Battery of Behavioral Tests Assessing General Locomotion, Muscular Strength, and Coordination in Mice

Behavioral testing is used in pre-clinical trials to assess the phenotypic effects and outcomes that a particular disease or treatment has on the animal&#39;s wellbeing and health. There are numerous behavioral tests that may be applied. We selected a test for general locomotion, the open field test (OFT); a test for muscular strength, the mesh test (MT); and a test for coordination, the rotarod test (RR). Testing can be accomplished on a weekly or monthly basis. As a test for general locomotion, the OFT works by objectively monitoring movement parameters while the mouse is in an open field apparatus. The field is generally a 2&#39; x 2&#39; box, and the movements are recorded through laser sensing or through video capture. The mouse is placed in the center of the open field and allowed to move freely for the test. The MT uses the latency for a mouse to fall off an inverted screen as a measure of muscular strength. A mouse is placed on a screen, which is inverted over a clear box, and is timed for their latency to fall. Three trials are performed, with the best of the three trials scored for that day. A score of 60 s is the maximum time a mouse is left inverted. Mice are given a 5-min rest period between mesh test trials. Lastly, an accelerated protocol on the RR assesses motor coordination and endurance. During a trial, a mouse walks on a rotating rod as it increases in speed from 4 rpm to 40 rpm over 5 min. The trial ends when the mouse touches the magnetized pressure sensor upon falling. Each mouse undergoes three trials, and the best trial is scored for that day. This combined behavioral data allows for the global assessment of mobility, coordination, strength, and movement of the test animals. At least two out of the three behavioral testing measures must show improvement for an animal to qualify as having overall improved motor function.

Behavioral testing is used in pre-clinical trials to assess the phenotypic effects of a disease or treatment on an animal's wellbeing. In order to globally assess motor functioning, we selected tests for general locomotion, muscular strength, and coordination: the open field test, the mesh test, and the rotarod test, respectively.

Behavioral testing is used in pre-clinical trials to assess the phenotypic effects and outcomes that a particular disease or treatment has on the ...

Using Laser Doppler Imaging and Monitoring to Analyze Spinal Cord Microcirculation in Rat

Laser Doppler flowmetry (LDF) is a noninvasive method for blood flow (BF) measurement, which makes it preferable for measuring microcirculatory alterations of the spinal cord. In this article, our goal was to use both Laser Doppler imaging and monitoring to analyze the change of BF after spinal cord injury. Both the laser Doppler image scanner and the probe/monitor were being employed to obtain each readout. The data of LDPI provided a local distribution of BF, which gave an overview of perfusion around the injury site and made it accessible for comparative analysis of BF among different locations. By intensely measuring the probing area over a period of time, a combined probe was used to simultaneously measure the BF and oxygen saturation of the spinal cord, showing overall spinal cord perfusion and oxygen supply. LDF itself has a few limitations, such as relative flux, sensitivity to movement, and biological zero signal. However, the technology has been applied in clinical and experimental study due to its simple setup and rapid measurement of BF.

Here we present a combination of laser Doppler perfusion imaging (LDPI) and laser Doppler perfusion monitoring (LDPM) to measure spinal cord local blood flows and oxygen saturation (SO2), as well as a standardized procedure for introducing spinal cord trauma on rat.

Laser Doppler flowmetry (LDF) is a noninvasive method for blood flow (BF) measurement, which makes it preferable for measuring microcirculatory ...

The Unpredictable Chronic Mild Stress Protocol for Inducing Anhedonia in Mice

Depression is a highly prevalent and debilitating condition, only partially addressed by current pharmacotherapies. The lack of response to treatment by many patients prompts the need to develop new therapeutic alternatives and to better understand the etiology of the disorder. Pre-clinical models with translational merits are rudimentary for this task. Here we present a protocol for the unpredictable chronic mild stress (UCMS) method in mice. In this protocol, adolescent mice are chronically exposed to interchanging unpredictable mild stressors. Resembling the pathogenesis of depression in humans, stress exposure during the sensitive period of mice adolescence instigates a depressive-like phenotype evident in adulthood. UCMS can be used for screenings of antidepressants on the variety of depressive-like behaviors and neuromolecular indices. Among the more prominent tests to assess depressive-like behavior in rodents is the sucrose preference test (SPT), which reflects anhedonia (core symptom of depression). The SPT will also be presented in this protocol. The ability of UCMS to induce anhedonia, instigate long-term behavioral deficits and enable reversal of these deficits via chronic (but not acute) treatment with antidepressants strengthens the protocol&#39;s validity compared to other animal protocols for inducing depressive-like behaviors.

Here we present the unpredictable chronic mild stress protocol in mice. This protocol induces a long-term depressive-like phenotype and enables to assess the efficacy of putative antidepressants in reversing the behavioral and neuromolecular depressive-like deficits.

Depression is a highly prevalent and debilitating condition, only partially addressed by current pharmacotherapies. The lack of response to treatment by ...

A Wind Tunnel for Odor Mediated Insect Behavioural Assays

Olfaction is the most important sensory mechanism by which many insects interact with their environment and a wind tunnel is an excellent tool to study insect chemical ecology. Insects can locate point sources in a three-dimensional environment through the sensory interaction and sophisticated behavior. The quantification of this behavior is a key element in the development of new tools for pest control and decision support. A wind tunnel with a suitable flight section with laminar air flow, visual cues for in-flight feedback and a variety of options for the application of odors can be used to measure complex behaviour which subsequently may allow the identification of attractive or repellent odors, insect flight characteristics, visual-odor interactions and interactions between attractants and odors lingering as background odors in the environment. A wind tunnel holds the advantage of studying the odor mediated behavioural repertoire of an insect in a laboratory setting. Behavioural measures in a controlled setting provide the link between the insect physiology and field application. A wind tunnel must be a flexible tool and should easily support the changes to setup and hardware to fit different research questions. The major disadvantage to the wind tunnel setup described here, is the clean odor background which necessitates special attention when developing a synthetic volatile blend for field application.

Here, we describe the construction and use of a wind tunnel for odor mediated behavioural assays with insects. The wind tunnel design facilitates the release of odor sources by several methods, with and without visual stimuli. Wind tunnel experiments are important methods to identify behaviorally active volatile chemicals.

Olfaction is the most important sensory mechanism by which many insects interact with their environment and a wind tunnel is an excellent tool to study ...

Lexical Decision Task for Studying Written Word Recognition in Adults with and without Dementia or Mild Cognitive Impairment

Older adults are slower at recognizing visual objects than younger adults. The same is true for recognizing that a letter string is a real word. People with Alzheimer&#39;s disease (AD) or Mild Cognitive Impairment (MCI) demonstrate even longer responses in written word recognition than elderly controls. Despite the general tendency towards slower recognition in aging and neurocognitive disorders, certain characteristics of words influence word recognition speed regardless of age or neuropathology (e.g., a word&#8217;s frequency of use). We present here a protocol for examining the influence of lexical characteristics on word recognition response times in a simple lexical decision experiment administered to younger and older adults and people with MCI or AD. In this experiment, participants are asked to decide as quickly and accurately as possible whether a given letter string is an actual word or not. We also describe mixed-effects models and principal components analysis that can be used to detect the influence of different types of lexical variables or individual characteristics of participants on word recognition speed.

This article describes how to implement a simple lexical decision experiment to assess written word recognition in neurologically healthy participants and in individuals with dementia and cognitive decline. We also provide a detailed description of reaction time analysis using principal components analysis (PCA) and mixed-effects modeling.

Older adults are slower at recognizing visual objects than younger adults. The same is true for recognizing that a letter string is a real word. People ...