The authors have nothing to disclose.

All procedures and behavioral testing were approved by MacEwan University&#8217;s Animal Research Ethics Board under protocol number 06-11-12, which is in compliance with the Canadian Council for Animal Care&#8217;s guidelines for the care and use of experimental animals.
1. Prepare Dosing Tanks, Solutions, and Administration Schedule
<ol>
	<li>Prepare an administration schedule such that the animals are dosed in the same environment and during the same time of day to avoid any confounds of time or biasing to visual stimuli.</li>
	<li>Obtain as many identical, 1.5 L, clear polypropylene spawning tanks as necessary for the number of group sizes. Use groups of 8 fish per tank, which allows for 2 groups of fish to be tested per day later on in the procedure (see step 3). Use one holding tank and one dosing tank per group (2x total number of groups).
	<ol>
		<li>Place 400 &#181;m spawning inserts in all holding tanks. Fill the tanks with habitat water or reverse osmosis water at the correct temperature (for zebrafish, 25-28 &#176;C) that is consistent with the temperature fish are normally housed at. 
		NOTE: There can be undesired chemical interactions between some drugs and the chemical components of buffered habitat water. In this situation, use reverse osmosis water buffered with minimal or no aquarium salts for drug administration, as well as for the control groups.</li>
		<li>Ensure that the tanks are in a neutral environment to avoid conditioning fish to external visual stimuli during dosing.</li>
	</ol>
	</li>
	<li>Prepare the drug solution. Mix the appropriate amount of the drug with habitat water in the spawning tanks. Prepare the 0.2% ethanol solution by combining 3 ml of a high grade ethanol (95% non-denatured ethanol) with 1,497 ml of water. Prepare the 1.4% ethanol solution by combining 21 ml of ethanol with 1,479 ml of water.</li>
</ol>
2. Netting Fish and Ethanol Administration Procedure
<ol>
	<li>Carefully net fish from their habitat tanks and transfer into the appropriate holding tank containing the spawning insert. Ideally, house the fish in the spawning insert to eliminate netting altogether.</li>
	<li>With all fish in their respective holding tanks, gently lift the spawning insert out of the holding tank and place it into the appropriate drug solution tank (Figure 1A).
	<ol>
		<li>Record the dosing time as required. Use 30 min in the ethanol solution for the procedure described here.</li>
		<li>If possible, have assistants help with the transfer of all experimental groups to the drug solution simultaneously to ensure precise dosing time. Alternatively, transfer one group at a time and keep track of individual groups&#8217; dosing times (Figure 1A).</li>
	</ol>
	</li>
	<li>At the end of the requisite dosing period, remove the fish from the ethanol solution by carefully lifting the spawning insert out of the drug solution and placing gently back into the holding tank.</li>
	<li>Gently net the fish in the holding tanks and place them back into their habitats until the next scheduled dosing time, or place the spawning insert back into the holding tank to eliminate netting.</li>
	<li>As mentioned previously, if possible within the parameters of animal housing equipment, house the animals in the same tank and spawning insert that is used as the holding tank. This will eliminate netting altogether during the administration procedure.</li>
</ol>
3. Behavioral Testing
<ol>
	<li>Obtain a light/dark arena 9.5 cm wide by 55 cm long and 9.5 cm deep with a white waterproof floor (Figure 1B). Affix white and black waterproof non-reflective paper to the inside walls of the arena using velcro, with half of the arena covered in white and half covered in black. Fill the arena to a depth of 5 cm with habitat water at a temperature of 25-28 &#176;C. Maintain this temperature throughout testing.</li>
	<li>Minimalize external visual stimuli by constructing a white three-sided enclosure for the arena to be situated in. Ensure the testing area has diffuse overhead lighting that does not cause reflections on the water surface, yet is sufficiently bright for the movement tracking software, or post-hoc manual quantification from video images.</li>
	<li>Place the arena in the enclosure and set the recording and movement analysis parameters of the behavior tracking software. Set the trial duration to 5-15 min, depending on the research question. 
	NOTE: Here, we used 5 min.</li>
	<li>Transport the group of fish to be tested to the research area in the habitat tank and place them outside of the arena enclosure. Acclimate the fish for 10 min.</li>
	<li>Gently net a fish from the appropriate group and place in the center of the light/dark arena, being sure to release the fish when it is positioned parallel to the long axis of the arena to avoid biasing the fish to the light or dark zone.</li>
	<li>Begin recording behavior immediately after the animal is released. Watch for any software problems with tracking the fish or for fish jumping or freezing. Rotate the arena 180&#176; after half of the subjects have been tested to prevent any confounds due to biases resulting from which end of the arena is oriented toward the open end of the enclosure.</li>
	<li>After the trial has ended, gently net and remove the fish from the arena to a holding tank or habitat tank.</li>
</ol>
4. Analysis
<ol>
	<li>Examine time spent in light versus dark zones. For each group and each fish, obtain the relative time spent in the light and dark zones and analyze using a one sample t-test (or Wilcoxon signed rank test for nonparametric data; difference from (half of the total trial time) 150 sec) to determine if groups significantly prefer one area over the other.</li>
	<li>To compare preferences, calculate a preference index by subtracting the time spent in the light zone from the time spent in the dark zone and compare differences between groups. t-tests can be used to compare two groups. Compare multiple groups with a one-way analysis of variance utilizing Tukey&#8217;s HSD post hoc test where necessary (or Kruskal-Wallis test with Dunn&#8217;s multiple comparison post hoc test for nonparametric data).</li>
	<li>Compare velocity, number of zone transitions, meandering, and immobility across groups. Use one-way analysis of variance utilizing Tukey&#8217;s HSD post hoc test where necessary (or Kruskal-Wallis test with Dunn&#8217;s multiple comparison post hoc test for nonparametric data).</li>
</ol>

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Modeling human disease in zebrafish.</a> Journal of Clinical Investigation. 122 (7), 2337-2343 (2012).</li><li>Miller, N., Greene, K., Dydinski, A., Gerlai, R. <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+nicotine+and+alcohol+on+zebrafish+(+Danio+rerio)+shoaling.">Effects of nicotine and alcohol on zebrafish ( Danio rerio) shoaling.</a> Behavioural brain research. , (2012).</li><li>Bencan, Z., Sledge, D., Levin, E. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Buspirone,+chlordiazepoxide+and+diazepam+effects+in+a+zebrafish+model+of+anxiety.">Buspirone, chlordiazepoxide and diazepam effects in a zebrafish model of anxiety.</a> Pharmacology Biochemistry and Behavior. 94 (1), 75-80 (2009).</li><li>Holcombe, A., Howorko, A., Powell, R. A., Schalomon, M., Hamilton, T. 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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=Understanding+behavioral+and+physiological+phenotypes+of+stress+and+anxiety+in+zebrafish.">Understanding behavioral and physiological phenotypes of stress and anxiety in zebrafish.</a> Behavioural brain research. 205 (1), 38-44 (2009).</li><li>Gebauer, D. L., 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+anxiolytics+in+zebrafish:+Similarities+and+differences+between+benzodiazepines,+buspirone+and+ethanol.">Effects of anxiolytics in zebrafish: Similarities and differences between benzodiazepines, buspirone and ethanol.</a> Pharmacology Biochemistry and Behavior. 99 (3), 480-486 (2011).</li><li>Serra, M. 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T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anxiolytic+effects+of+nicotine+in+zebrafish.">Anxiolytic effects of nicotine in zebrafish.</a> Physiology &amp; Behavior. 90 (1), 54-58 (2007).</li><li>Gerlai, R., Chatterjee, D., Pereira, T., Sawashima, T., Krishnannair, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acute+and+chronic+alcohol+dose:+population+differences+in+behavior+and+neurochemistry+of+zebrafish.">Acute and chronic alcohol dose: population differences in behavior and neurochemistry of zebrafish.</a> Genes, Brain and Behavior. 8 (6), 586-599 (2009).</li><li>Mathur, P., Berberoglu, M. 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I., 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=Tolerance+and+withdrawal+in+goldfish+exposed+to+ethanol.">Tolerance and withdrawal in goldfish exposed to ethanol.</a> Physiology &amp; Behaviour. 87 (3), 460-468 (2006).</li><li>Hamilton, T. J., Holcombe, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tresguerres,+M.CO2-induced+ocean+acidification+increases+anxiety+in+rockfish+via+alteration+of+GABAA+receptor+functioning.">Tresguerres, M.CO2-induced ocean acidification increases anxiety in rockfish via alteration of GABAA receptor functioning.</a> Proceedings of the Royal Society B. , (2014).</li><li>Ramsay, J. M., Feist, G. W., Varga, Z. M., Westerfield, M., Kent, M. L., Schreck, C. 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The authors acknowledge Joshua Gallup for use of his photography equipment used for Figure 1. This work was supported by a Natural Sciences and Engineering Research Council (NSERC) Canada Discovery grant (to T.J.H.).

Previous studies involving drug administration in zebrafish have simply relied on netting fish to transport them from their home tank into the drug solution12,16. Netting is not always consistent and often takes longer than expected due to the escape response of the zebrafish, which has significant individual variability. Traditional transfer methods, while useful, can be improved upon by decreasing the amount of total time the fish spend outside of water, as well as decreasing the amount of variability in tra...

The zebrafish (Danio rerio) is a small teleost species originating in India that is a useful model organism for behavioral1 and medical research2,3. Zebrafish are also commonly used in the testing of various pharmacological substances in order to characterize their impact on behavior. Various dosages and schedules of drug administration have been used to investigate the behavior of the zebrafish after the administration of compounds such as stimulants4, anxiolytics5 and ethanol6-8.
Our lab has investigated the effects of differing schedules of ethanol administration on zebrafish anxiety and locomotion in the well-validated light/dark assay9,20, also commonly referred to as the scototaxic assay. A new method of ethanol administration was developed to increase efficiency for repetitive, daily administration over a long period of time (21 days)6. Previously used methods were practical, however, we sought to develop a method that reduced netting, with its associated time costs, and allowed simultaneous, precisely timed administration of the drug of interest to large numbers of fish. In traditional research using ethanol, zebrafish are netted and transferred from one tank to another containing the appropriate mixture of ethanol and water10-12. While this method is widely accepted, netting zebrafish may increase the variability in the time taken to introduce and remove the fish from the drug solution. Therefore, the exact exposure to the compound of interest may vary over the course of an experiment involving repeated dosing. A method that reduces sources of error stemming from variability in transport times is thus desirable. With our method we are able to move all fish simultaneously, resulting in identical dosing time in each fish. Following ethanol exposure (described here), zebrafish can be tested in any number of behavioral assays, including those that assess anxiety. Dosing groups of fish using the new method has practical uses beyond the ability to accurately replicate and standardize dosing between subjects and across groups of fish. The advent of new software that allows for the tracking of multiple fish at once may see researchers utilize our methods to ensure replicability and accuracy in their experiments. Considering the widespread use of zebrafish as a model organism for behavioral neuroscience, this method will increase efficiency and practicality in future pharmacological studies.
In the present paradigm, a repeated dosing schedule was employed that approximately mirrors human drinking schedules. Fish were randomly assigned to one of three groups: control, daily-moderate, or weekly-binge. The dosing schedule was 21 days in duration, chosen because it significantly exceeded exposure times in previous studies7. Control fish received zero alcohol, daily-moderate fish received 0.2% alcohol once per day, and weekly-binge fish received 1.4% alcohol once per week. The light/dark task was used to assess anxiety after 2 days of withdrawal. This is a relatively simple test to administer which uses a rectangular arena in which the walls on one side are white and on the other side are dark9. Adult zebrafish robustly prefer the dark side of the arena under control conditions6,9,13. Increased anxiety is operationally defined as significantly more time spent in the dark zone, and decreased anxiety can be assumed when the fish spends relatively more time spent in the light zone. With motion-tracking software, other informative variables can also be quantified, including average velocity, immobility, meandering, and zone transitions14.
The dosing method developed in our laboratory can apply to any research in which water-soluble compounds are administered to one or more zebrafish. Many other pharmacological agents which may benefit from this methodology are currently being tested in zebrafish. Commonly tested compounds include nicotine, chlordiazepoxide, buspirone, and scopolamine, which are dissolved in a similar manner to ethanol; by mixing the appropriate amount of the chemical into water. Therefore, the general scope of this procedure is much wider and not limited to ethanol. Furthermore, after dosing with drugs for multiple days, the light/dark task is only one of many behavioral tests that could be employed. After drug administration or during withdrawal, other popular assays that can be utilized include the novel tank diving test15 and tests of social behavior such as shoaling16. The following procedure will outline an efficient method of repeatedly transferring groups of fish or individual fish into solutions containing a pharmacological compound of interest. Additionally, the process of testing anxiety with the light/dark test in groups of fish who are in withdrawal after being exposed to long schedules of alcohol administration will be described.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Three Shelf benchtop housing system</td>
			<td>Aquatic Habitats</td>
			<td>N/A</td>
			<td><a href="http://aquatichabitats.com/research-systems/z-hab-system/">http://aquatichabitats.com/research-systems/z-hab-system/</a></td>
		</tr>
		<tr>
			<td>1.5L Spawning tank w/400 micron baffle</td>
			<td>Aquatic Habitats</td>
			<td>N/A</td>
			<td><a href="http://aquatichabitats.com/consumables/tanks-lids-and-baffles/info/nursery-tank-and-baffles/">http://aquatichabitats.com/consumables/tanks-lids-and-baffles/info/nursery-tank-and-baffles/</a></td>
		</tr>
		<tr>
			<td>Pure Grain Ethanol</td>
			<td>Luxco, INC</td>
			<td>N/A</td>
			<td><a href="http://www.fishersci.com/ecomm/servlet/fsproductdetail?storeId=10652&amp;aid=3759149&amp;store=Scientific">http://www.luxco.com/public/brands/brands.asp?brandid=21</a></td>
		</tr>
		<tr>
			<td>Ethovision XT Motion tracking software</td>
			<td>Noldus Information Technology</td>
			<td></td>
			<td><a href="http://www.noldus.com/animal-behavior-research/products/ethovision-xt">http://www.noldus.com/animal-behavior-research/products/ethovision-xt</a></td>
		</tr>
		<tr>
			<td>Pipette</td>
			<td>Eppendorf Canada</td>
			<td></td>
			<td><a href="http://www.eppendorf.ca/int/index.php?l=211&amp;pb=e396f9e705e754a3&amp;action=products&amp;contentid=1&amp;catalognode=9477.">http://www.eppendorf.ca/int/index.php?l=211&#38;pb=e396f9e705e754a3&#38;action=products&#38;contentid=1&#38;catalognode=9477.&#160;</a></td>
		</tr>
		<tr>
			<td>Light/Dark Arena</td>
			<td>Custom</td>
			<td></td>
			<td>Construct as per procedure description. 9.5cm wide, 9.5cm deep, 55cm long</td>
		</tr>
	</tbody>
</table>

a novel method of drug administration to multiple zebrafish (danio rerio) and the quantification of withdrawal

Anxiety testing in zebrafish is often studied in combination with the application of pharmacological substances. In these studies, fish are routinely netted and transported between home aquaria and dosing tanks. In order to enhance the ease of compound administration, a novel method for transferring fish between tanks for drug administration was developed. Inserts that are designed for spawning were used to transfer groups of fish into the drug solution, allowing accurate dosing of all fish in the group. This increases the precision and efficiency of dosing, which becomes very important in long schedules of repeated drug administration. We implemented this procedure for use in a study examining the behavior of zebrafish in the light/dark test after administering ethanol with differing 21 day schedules. In fish exposed to daily-moderate amounts of alcohol there was a significant difference in location preference after 2 days of withdrawal when compared to the control group. However, a significant difference in location preference in a group exposed to weekly-binge administration was not observed. 
This protocol can be generalized for use with all types of compounds that are water-soluble and may be used in any situation when the behavior of fish during or after long schedules of drug administration is being examined. The light/dark test is also a valuable method of assessing withdrawal-induced changes in anxiety.

To maintain accuracy and control in pharmacological studies with zebrafish it is important to time the duration of ethanol administration consistently and accurately as described above. Our procedure can increase the ease and throughput of the dosing procedure. The administration of ethanol on either a weekly-binge or daily-moderate schedule resulted in altered anxiety levels, measured with the light/dark test, compared to controls. When tested two days after the last dosing, zebrafish in the control group (who received ...

Watch this Scientific Journal Video about A Novel Method of Drug Administration to Multiple Zebrafish Danio rerio and the Quantification of Withdrawal at JoVE.com

A Novel Method of Drug Administration to Multiple Zebrafish Danio rerio and the Quantification of Withdrawal

A novel method for reducing variability when exposing fish to drugs is explained. Fish exposed to various patterns of ethanol exposure were found to have altered anxiety levels during withdrawal in a light/dark scototaxic assay.

A Novel Method of Drug Administration to Multiple Zebrafish (Danio rerio) and the Quantification of Withdrawal

Anxiety testing in zebrafish is often studied in combination with the application of pharmacological substances. In these studies, fish are routinely ...

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12.0K Views.  MacEwan University. A novel method for reducing variability when exposing fish to drugs is explained. Fish exposed to various patterns of ethanol exposure were found to have altered anxiety levels during withdrawal in a light/dark scototaxic assay.

Video: A Novel Method of Drug Administration to Multiple Zebrafish Danio rerio and the Quantification of Withdrawal

Novel Apparatus and Method for Drug Reinforcement

Animal models of reinforcement have proven to be useful for understanding the neurobiological mechanisms underlying drug addiction. Operant drug self-administration and conditioned place preference (CPP) procedures are expansively used in animal research to model various components of drug reinforcement, consumption, and addiction in humans. For this study, we used a novel approach to studying drug reinforcement in rats by combining traditional CPP and self-administration methodologies. We assembled an apparatus using two Med Associate operant chambers, sensory stimuli, and a Plexiglas-constructed neutral zone. These modifications allowed our experiments to encompass motivational aspects of drug intake through self-administration and drug-free assessment of drug/cue conditioning strength with the CPP test. In our experiments, rats self-administered cocaine (0.75 mg/kg/inj, i.v.) during either four (e.g., the "short-term") or eight (e.g., the "long-term") alternating-day sessions in an operant environment containing distinctive sensory cues (e.g., olfactory and visual). On the alternate days, in the other (differently-cued) operant environment, saline was available for self-infusion (0.1 ml, i.v.). Twenty-four hours after the last self-administration/cue-pairing session, a CPP test was conducted. Consistent with typical CPP findings, there was a significant preference for the chamber associated with cocaine self-administration. In addition, in animals undergoing the long-term experiment, a significant positive correlation between CPP magnitude and the number of cocaine-reinforced lever responses. In conclusion, this apparatus and approach is time and cost effective, can be used to examine a wide array of topics pertaining to drug abuse, and provides more flexibility in experimental design than CPP or self-administration methods alone.

Operant drug self-administration and conditioned place preference (CPP) procedures are expansively used in research to model various components of drug reinforcement, consumption, and addiction in humans. In this report, we combined traditional CPP and self-administration methods as a novel approach to studying drug reinforcement and addiction in rats.

Animal models of reinforcement have proven to be useful for understanding the neurobiological mechanisms underlying drug addiction.  Operant drug ...

Assessment of Ultrasonic Vocalizations During Drug Self-administration in Rats

Drug self-administration procedures are commonly used to study behavioral and neurochemical changes associated with human drug abuse, addiction and relapse. Various types of behavioral activity are commonly utilized as measures of drug motivation in animals. However, a crucial component of drug abuse relapse in abstinent cocaine users is "drug craving", which is difficult to model in animals, as it often occurs in the absence of overt behaviors. Yet, it is possible that a class of ultrasonic vocalizations (USVs) in rats may be a useful marker for affective responses to drug administration, drug anticipation and even drug craving. Rats vocalize in ultrasonic frequencies that serve as a communicatory function and express subjective emotional states. Several studies have shown that different call frequency ranges are associated with negative and positive emotional states. For instance, high frequency calls ("50-kHz") are associated with positive affect, whereas low frequency calls ("22-kHz") represent a negative emotional state. This article describes a procedure to assess rat USVs associated with daily cocaine self-administration. For this procedure, we utilized standard single-lever operant chambers housed within sound-attenuating boxes for cocaine self-administration sessions and utilized ultrasonic microphones, multi-channel recording hardware and specialized software programs to detect and analyze USVs. USVs measurements reflect emotionality of rats before, during and after drug availability and can be correlated with commonly assessed drug self-administration behavioral data such lever responses, inter-response intervals and locomotor activity. Since USVs can be assessed during intervals prior to drug availability (e.g., anticipatory USVs) and during drug extinction trials, changes in affect associated with drug anticipation and drug abstinence can also be determined. In addition, determining USV changes over the course of short- and long-term drug exposure can provide a more detailed interpretation of drug exposure effects on affective functioning.

Drug self-administration and ultrasonic vocalizations (USV) are used as behavioral assessments in animal research, but rarely in combination. The purpose of this article is to describe the advantages of recording USVs during drug self-administration procedures to assess affective responses to drug experience.

Drug self-administration procedures are commonly used to study behavioral and neurochemical changes associated with human drug abuse, addiction and ...

Microdialysis of Ethanol During Operant Ethanol Self-administration and Ethanol Determination by Gas Chromatography

Operant self-administration methods are commonly used to study the behavioral and pharmacological effects of many drugs of abuse, including ethanol. However, ethanol is typically self-administered orally, rather than intravenously like many other drugs of abuse. The pharmacokinetics of orally administered drugs are more complex than intravenously administered drugs. Because understanding the relationship between the pharmacological and behavioral effects of ethanol requires knowledge of the time course of ethanol reaching the brain during and after drinking, we use in vivo microdialysis and gas chromatography with flame ionization detection to monitor brain dialysate ethanol concentrations over time. 
Combined microdialysis-behavioral experiments involve the use of several techniques. In this article, stereotaxic surgery, behavioral training and microdialysis, which can be adapted to test a multitude of self-administration and neurochemical centered hypotheses, are included only to illustrate how they relate to the subsequent phases of sample collection and dialysate ethanol analysis. Dialysate ethanol concentration analysis via gas chromatography with flame-ionization detection, which is specific to ethanol studies, is described in detail. Data produced by these methods reveal the pattern of ethanol reaching the brain during the self-administration procedure, and when paired with neurochemical analysis of the same dialysate samples, allows conclusions to be made regarding the pharmacological and behavioral effects of ethanol.

A method to determine the time course of ethanol concentration in the brains of rats during operant ethanol self-administration is described. Gas chromatography with flame ionization detection is used to quantify ethanol in the dialysate samples, because it has the sensitivity required for the small volumes that are generated.

Operant self-administration methods are commonly used to study the behavioral and pharmacological effects of many drugs of abuse, including ethanol.  ...

Stab Wound Injury of the Zebrafish Adult Telencephalon: A Method to Investigate Vertebrate Brain Neurogenesis and Regeneration

Adult zebrafish have an amazing capacity to regenerate their central nervous system after injury. To investigate the cellular response and the molecular mechanisms involved in zebrafish adult central nervous system (CNS) regeneration and repair, we developed a zebrafish model of adult telencephalic injury.
In this approach, we manually generate an injury by pushing an insulin syringe needle into the zebrafish adult telencephalon. At different post injury days, fish are sacrificed, their brains are dissected out and stained by immunohistochemistry and/or in situ hybridization (ISH) with appropriate markers to observe cell proliferation, gliogenesis, and neurogenesis. The contralateral unlesioned hemisphere serves as an internal control. This method combined for example with RNA deep sequencing can help to screen for new genes with a role in zebrafish adult telencephalon neurogenesis, regeneration, and repair.

To shed light on the cellular and molecular mechanisms of zebrafish adult neurogenesis and regeneration, we developed a protocol for invasive surgery causing mechanical injuries in the zebrafish adult telencephalon and subsequent monitoring of changes in the stabbed hemisphere by immunohistochemistry or in situ hybridization.

Adult zebrafish have an amazing capacity to regenerate their central nervous system after injury. To investigate the cellular response and the molecular ...

Assessment of Neuronal Viability Using Fluorescein Diacetate-Propidium Iodide Double Staining in Cerebellar Granule Neuron Culture

Primary cultured Cerebellar Granule Neurons (CGNs) have been widely used as an in vitro model in neuroscience and neuropharmacology research. However, the co-existence of glial cells and neurons in CGN culture might lead to biases in the accurate assessment of neuronal viability. Fluorescein diacetate (FDA) and Propidium Iodide (PI) double staining has been used to measure cell viability by simultaneously evaluating the viable and dead cells. We used FDA-PI double staining to improve the sensitivities of the colorimetric assays and to evaluate neuronal viability in CGNs. Furthermore, we added blue fluorescent DNA stains (e.g., Hoechst) to improve the accuracy. This protocol describes how to improve the accuracy of assessment of neuronal viability by using these methods in CGN culture. Using this protocol, the number of glial cells can be excluded by using fluorescence microscopy. A similar strategy can be applied to distinguish the unwanted glial cells from neurons in various mixed cell cultures, such as primary cortical culture and hippocampal culture.

This protocol describes how to accurately measure neuronal viability using Fluorescein diacetate (FDA) and Propidium Iodide (PI) double staining in cultured cerebellar granule neurons, a primary neuronal culture used as an in vitro model in neuroscience and neuropharmacology research.

Primary cultured Cerebellar Granule Neurons (CGNs) have been widely used as an in vitro model in neuroscience and neuropharmacology research. However, the ...

A Novel Method to Model Chronic Traumatic Encephalopathy in Drosophila

Chronic Traumatic Encephalopathy (CTE) is an established neurodegenerative disease that is closely associated with exposure to repetitive mild Traumatic Brain Injury (mTBI). The mechanisms responsible for its complex pathological changes remain largely elusive, despite a recent consensus to define the neuropathological criteria. Here, we describe a novel method to develop a model of CTE in Drosophila melanogaster&#160;(Drosophila&#160;)&#160;in an attempt to identify the key genes and pathways that lead to the characteristic hyperphosphorylated tau accumulation and neuronal death in the brain. Adjustable-strength impacts to inflict mild closed injury are delivered directly to the fly head, subjecting the head to rapid acceleration and deceleration. Our method eliminates the potential problems inherent with other Drosophila mTBI models (e.g.,animal death might be induced by damage to other parts of the body or to internal organs). The less labor- and cost-intensive animal care, short life span, and extensive genetic tools make the fruit fly ideal to study CTE pathogenesis and make it possible to perform large-scale, genome-wide forward genetic and pharmacological screens. We anticipate that the ongoing characterization of the model will generate important mechanistic insights on disease prevention and therapeutic approaches.

A Novel Method to Model Chronic Traumatic Encephalopathy in Drosophila

Here, we describe a new approach to inflict closed-head traumatic brain injury in Drosophila melanogaster. Our method has the advantage of directly delivering repetitive impacts with adjustable strength to the head alone. Further exploration of the invertebrate system will help to illuminate the pathogenesis of chronic traumatic encephalopathy.

Chronic Traumatic Encephalopathy (CTE) is an established neurodegenerative disease that is closely associated with exposure to repetitive mild Traumatic ...

Assay Development for High Content Quantification of Sod1 Mutant Protein Aggregate Formation in Living Cells

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that can be caused by inherited mutations in the gene encoding copper-zinc superoxide dismutase 1 (SOD1). The structural instability of SOD1 and the detection of SOD1-positive inclusions in familial-ALS patients supports a potential causal role for misfolded and/or aggregated SOD1 in ALS pathology. In this study, we describe the development of a cell-based assay designed to quantify the dynamics of SOD1 aggregation in living cells by high content screening approaches. Using lentiviral vectors, we generated stable cell lines expressing wild-type and mutant A4V SOD1 tagged with yellow fluorescent protein and found that both proteins were expressed in the cytosol without any sign of aggregation. Interestingly, only SOD1 A4V stably expressed in HEK-293, but not in U2OS or SH-SY5Y cell lines, formed aggregates upon proteasome inhibitor treatment. We show that it is possible to quantify aggregation based on dose-response analysis of various proteasome inhibitors, and to track aggregate-formation kinetics by time-lapse microscopy. Our approach introduces the possibility of quantifying the effect of ALS mutations on the role of SOD1 in aggregate formation as well as screening for small molecules that prevent SOD1 A4V aggregation.

We describe a method to quantify the aggregation of misfolded proteins. Our protocol details lentiviral induced stable cell line generation, automated confocal imaging, and image analysis of protein aggregates. As an illustrative application, we studied the effect of small molecules in promoting SOD1 aggregation in a time- and dose-dependent manner.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that can be caused by inherited mutations in the gene encoding copper-zinc ...

A Rat Model of Central Fatigue Using a Modified Multiple Platform Method

In this article, we introduced a rat model of central fatigue using the modified multiple platform method (MMPM). The Multiple Platform box was designed as a water tank with narrow platforms on the bottom. The model rats were put into the tank and stood on the platforms for 14 h (18:00 - 8:00) per day for a consecutive 21 days, with a blank control group set for contrast. At the end of modeling, rats in the model group showed an obvious fatigued appearance. To assess the model, we performed several behavioral tests, including the open field test (OFT), the elevated plus maze (EPM) test, and the exhaustive swimming (ES) test. The results showed that anxiety, spatial cognition impairment, poor muscle performance, and declined voluntary activity presented in model rats confirm the diagnosis of&#160;central fatigue. Changes of the central neurotransmitters also verified the result. In conclusion, the model successfully simulated central fatigue, and future study with the model may help reveal the pathological mechanism of the disease.

Here, we present a protocol to introduce a rat model of central fatigue using the modified multiple platform method (MMPM).

In this article, we introduced a rat model of central fatigue using the modified multiple platform method (MMPM). The Multiple Platform box was designed ...

A Volumetric Method for Quantification of Cerebral Vasospasm in a Murine Model of Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a subtype of hemorrhagic stroke. Cerebral vasospasm that occurs in the aftermath of the bleeding is an important factor determining patient outcome and is therefore frequently taken as a study endpoint. However, in small animal studies on SAH, quantification of cerebral vasospasm is a major challenge. Here, an ex vivo method is presented that allows quantification of volumes of entire vessel segments, which can be used as an objective measure to quantify cerebral vasospasm. In a first step, endovascular casting of the cerebral vasculature is performed using a radiopaque casting agent. Then, cross-sectional imaging data are acquired by micro computed tomography. The final step involves 3-dimensional reconstruction of the virtual vascular tree, followed by an algorithm to calculate center lines and volumes of the selected vessel segments. The method resulted in a highly accurate virtual reconstruction of the cerebrovascular tree shown by a diameter-based comparison of anatomical samples with their virtual reconstructions. Compared with vessel diameters alone, the vessel volumes highlight the differences between vasospastic and non-vasospastic vessels shown in a series of SAH and sham-operated mice.

The goal of this article is to present a method that allows a 3-dimensional reconstruction of the cerebrovascular tree in mice after micro computed tomography and determination of volumes of entire vessel segments that can be used to quantify cerebral vasospasm in murine models of subarachnoid hemorrhage.

Subarachnoid hemorrhage (SAH) is a subtype of hemorrhagic stroke. Cerebral vasospasm that occurs in the aftermath of the bleeding is an important factor ...

Autoradiography as a Simple and Powerful Method for Visualization and Characterization of Pharmacological Targets

In vitro autoradiography aims to visualize the anatomical distribution of a protein of interest in tissue from experimental animals as well as humans. The method is based on the specific binding of a radioligand to its biological target. Therefore, frozen tissue sections are incubated with radioligand solution, and the binding to the target is subsequently localized by the detection of radioactive decay, for example, by using photosensitive film or phosphor imaging plates. Resulting digital autoradiograms display remarkable spatial resolution, which enables quantification and localization of radioligand binding in distinct anatomical structures. Moreover, quantification allows for the pharmacological characterization of ligand affinity by means of dissociation constants (Kd), inhibition constants (Ki) as well as the density of binding sites (Bmax) in selected tissues. Thus, the method provides information about both target localization and ligand selectivity. Here, the technique is exemplified with autoradiographic characterization of the high-affinity &#947;-hydroxybutyric acid (GHB) binding sites in mammalian brain tissue, with special emphasis on methodological considerations regarding the binding assay parameters, the choice of the radioligand and the detection method.

The method of autoradiography is routinely used to study binding of radioligands to tissue sections for determination of qualitative or quantitative pharmacology.

In vitro autoradiography aims to visualize the anatomical distribution of a protein of interest in tissue from experimental animals as well as humans. The ...