We want to express our gratitude to the Biomedical Sciences PhD Program at the National Autonomous University of Mexico and to the support provided by Consejo Nacional de Humanidades, Ciencias y Tecnolog&#237;as (CONAHCYT), No. CVU: 11025222. This work was partially supported by the UNAM-DGAPA-PAPIIT grant IN207423. We thank Andrea Mondrag&#243;n Garc&#237;a and Jos&#233; Enrique Ram&#237;rez S&#225;nchez for their technical support.

All experiments were conducted according to the Mexican Official Standard of Technical Specifications for the Production and Use of Laboratory Animals (NOM-062-ZOO-1999) and in full compliance with the guidelines set forth by the Internal Committee for the Care and Use of Laboratory Animals (CICUAL) at the National Autonomous University of Mexico (UNAM).
1. Animals
<ol>
	<li>To follow this protocol, individually house 27 C57BLC/6 male mice, aged 1 month and weighing 16-20 g, in cages under controlled environmental conditions: a 12-12 h light-dark cycle (06:00 on, 18:00 off), maintaining the temperature at 21 &#177; 22 &#176;C and humidity levels at 70 &#177; 10%. 
	NOTE: In this study, we exclusively used male mice to eliminate the effects of female hormones during binge-type intake. However, in another study18, we applied the same model to female mice and observed no differences in binge intake.</li>
</ol>
2. Habituation
<ol>
	<li>Provide the 30-day-old mice with ad libitum access to standard chow and water. Place them in individual cages to facilitate measuring water and food consumption.</li>
	<li>Provide an enriched environment, including a paper tube, to all the mice and provide wood shavings as bedding.</li>
	<li>Measure body weight, food, and water consumption every 24 h for 7 days.</li>
</ol>
3. Binge eating model
<ol>
	<li>On day 7 of the habituation period, randomly assign the rodents (N= 27) into one of the following three groups.</li>
	<li>Provide all subjects with access to the HPF (nutritional content per 100: 480 kcal, 19g of fat, 70 g of carbohydrates, 5.1 g of protein, 0.13 g of salt) for 2 h (from 16:00 to 18:00) to minimize neophobia toward the HPF.</li>
	<li>Continue the specified feeding conditions for each group consistently for a period of 26 days.
	<ol>
		<li>Chow Group (CG) n = 9: provide ad libitum access to standard chow and water.</li>
		<li>Continuous Group (CoG) n = 9; provide ad libitum access to standard chow, HPF, and water.</li>
		<li>Intermittent Group (IG) n = 9: provide ad libitum access to standard chow and water but give them HPF only on specific days (1, 3, 5, 8, 10, 12, 15, 17, 19, 22, 24, and 26) for 2 h (from 16:00 to 18:00 h).</li>
	</ol>
	</li>
	<li>From the first session to session 26, measure body weight, standard chow intake, palatable food intake, and water consumption for all subjects at 16:00 h and again at 18:00 h.</li>
</ol>
4. Specifical instructions
<ol>
	<li>Place the standard chow on the cage racks and the HPF in small plastic containers. In each session, randomly place these containers at the corners of the cages (left posterior, right posterior, right anterior, and left anterior).</li>
	<li>Replenish water (280-300 mL) and standard chow (10-15 g) on Mondays, Wednesdays, and Fridays.</li>
	<li>Replace the HPF (4-4.5 g) daily for the CoG. For the IG, place the HPF (4-4.5 g) on Mondays, Wednesdays, and Fridays at 16:00 h. Randomly distribute the HPF by color (brown, blue, red, orange, green, and yellow), with no preference observed for any color.</li>
	<li>On day 7 of habituation, give the mice assigned to the CoG group the HPF at 16:00 h. Measure all the animals for standard chow intake, body weight, and water consumption.</li>
</ol>
5. Data analysis
<ol>
	<li>For 24 h intake measurements, record the values at 16:00 h on the previous day and 16:00 h on the current day. For instance, to evaluate the consumption of day 2, subtract the values for standard chow, the HPF, water, and body weight from day 1 from those of day 2 for the same parameters.</li>
	<li>For 2 h intake measurements, record the values at 16:00 h and 18:00 h on the same day. For example, subtract the values for standard chow, the HPF, water, and body weight at 16:00 h from those at 18:00 h for the same parameters.</li>
	<li>Collect all data daily at two time points (16:00 h and 18:00 h), input them into a spreadsheet, and perform kcal calculations.
	<ol>
		<li>To calculate the kcal, convert the grams consumed of standard chow and HPF to kcal based on the energy value of each food using a proportion (e.g., standard chow: 3.02 kcal/g; HPF: 4.80 kcal/g).</li>
	</ol>
	</li>
	<li>Analyze and plot the data using the software of choice.
	<ol>
		<li>For statistical analysis, use the Kruskal-Wallis and Mann-Whitney U tests.</li>
	</ol>
	</li>
</ol>
6. Open field test
NOTE: A 22-day, 14:00 h, open field test was conducted according to the protocol described by Kraeuter and colleagues19. This protocol consists of placing the animals in the center of a black acrylic sheet box. The floor of the arena was white, and the grid was black. Behavior was recorded and quantified with a video tracking system. The system recorded the distance, speed, and time the animals spent in the center or periphery of the arena.
<ol>
	<li>Preparation of the test room and open field apparatus
	<ol>
		<li>For the arena, use a square chamber of 60 cm (length) x 60 cm (width) x 20 cm (height) made of black nonporous plastic.</li>
		<li>Clean the device before and between uses with 70% vol/vol ethanol to remove odor cues.</li>
		<li>Place the camera above the apparatus for optimal exploration view.</li>
		<li>To minimize stress, maintain temperature and humidity like the normal housing conditions. If the mice are moved from one housing room to another for the experiment, acclimate them to the new room for at least 1 h each day before use.</li>
	</ol>
	</li>
	<li>Performing the open field test
	<ol>
		<li>To remove a single mouse from the cage, gently grasp its tail and place it in the center of the open field maze. Activate the video tracking software using the autostart feature, which detects the investigator and begins recording as soon as the investigator is no longer in focus of the camera.</li>
		<li>Allow the mouse to move freely along the maze for 5 min. During this time, the tracking software will record the movement.</li>
		<li>At the end of the trial period, remove the animal from the arena and return it to its home cage.</li>
		<li>Before cleaning the maze, visually count the feces deposited and record them for later analysis.</li>
		<li>Remove all fecal pellets and clean any urine stains. Spray the apparatus floor and walls with 70% ethanol, then wipe with a clean paper towel. Allow the ethanol solution to dry completely.</li>
		<li>After testing all animals, return to the vivarium, clean the arena, and organize all used materials.</li>
	</ol>
	</li>
	<li>Data analysis 
	NOTE: The video tracking software facilitates the extraction of a range of data, such as the animals&#39; average speed, the distance traveled, and the time spent in the center and periphery of the apparatus.
	<ol>
		<li>Select the distance traveled and the time spent by the animals in the center and the periphery of the apparatus.</li>
		<li>Export the data from the tracking software into a spreadsheet or other preferred format for further statistical analysis.</li>
		<li>Analyze the data with the software of choice.</li>
	</ol>
	</li>
</ol>

Investigating Binge Eating Disorder with a Palatable Food Access Mouse Model

<ol>
	<li>. Obesity and overweight Available from: <a target="_blank" href="https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight">https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight</a> (2022)</li><li>McCuen-Wurst, C., 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=Disordered+eating+and+obesity:+between+binge-eating+disorder,+night-eating+syndrome,+and+weight-related+comorbidities.">Disordered eating and obesity: between binge-eating disorder, night-eating syndrome, and weight-related comorbidities.</a> Ann N Y Acad Sci. 1411 (1), 96-105 (2018).</li><li>Veling, H., 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=Stop+signals+decrease+choices+for+palatable+foods+through+decreased+food+evaluation.">Stop signals decrease choices for palatable foods through decreased food evaluation.</a> Front Psychol. 4, 875 (2013).</li><li>Pascual-Ausique, D., S&#225;nchez-Carracedo, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+complex+systems+approach+to+eating+disorders:+Towards+a+better+understanding+of+heterogeneity+and+treatment.">A complex systems approach to eating disorders: Towards a better understanding of heterogeneity and treatment.</a> Appetite. 107, 152-161 (2016).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Diagnostic and statistical manual of mental disorders. , (2013).</li><li>Torres, S., 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=Emotion-focused+cognitive+behavioral+therapy+in+comorbid+obesity+with+binge+eating+disorder:+A+pilot+study+of+feasibility+and+long-term+outcomes.">Emotion-focused cognitive behavioral therapy in comorbid obesity with binge eating disorder: A pilot study of feasibility and long-term outcomes.</a> Front Psychol. 11, 343 (2020).</li><li>Pipe, 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=Binge+eating+disorder+is+hidden+behind+a+wall+of+anxiety+disorders.">Binge eating disorder is hidden behind a wall of anxiety disorders.</a> J Psychiatry Neurosci. 46 (2), E208-E209 (2021).</li><li>Corwin, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bingeing+rats:+a+model+of+intermittent+excessive+behavior.">Bingeing rats: a model of intermittent excessive behavior.</a> Appetite. 46 (1), 11-15 (2006).</li><li>Lardeux, S., 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=Intermittent-access+binge+consumption+of+sweet+high-fat+liquid+does+not+require+opioid+or+dopamine+receptors+in+the+nucleus+accumbens.">Intermittent-access binge consumption of sweet high-fat liquid does not require opioid or dopamine receptors in the nucleus accumbens.</a> Behav Brain Res. 292, 194-208 (2015).</li><li>Kreisler, A. D., 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=Extended+vs.+brief+intermittent+access+to+palatable+food+differently+promote+binge-like+intake,+rejection+of+less+preferred+food,+and+weight+cycling+in+female+rats.">Extended vs. brief intermittent access to palatable food differently promote binge-like intake, rejection of less preferred food, and weight cycling in female rats.</a> Physiol Behav. 177, 305-316 (2017).</li><li>Romano, 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=Oleoylethanolamide+decreases+frustration+stress-induced+binge-like+eating+in+female+rats:+a+novel+potential+treatment+for+binge+eating+disorder.">Oleoylethanolamide decreases frustration stress-induced binge-like eating in female rats: a novel potential treatment for binge eating disorder.</a> Neuropsychopharmacology. 45 (11), 1931-1941 (2020).</li><li>Ormaechea, P., Boakes, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unpredictability+of+access+to+a+high+fat/high+sugar+food+can+increase+rats&#180;intake.">Unpredictability of access to a high fat/high sugar food can increase rats&#180;intake.</a> Physiol Behav. 266, 114182 (2023).</li><li>Hildebrandt, B. A., Ahmari, S. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Breaking+it+down:+Investigation+of+binge+eating+components+in+animal+models+to+enhance+translation.">Breaking it down: Investigation of binge eating components in animal models to enhance translation.</a> Front Psychiatry. 12, 728535 (2021).</li><li>Yasoshima, Y., Shimura, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+mouse+model+for+binge-like+sucrose+overconsumption:+Contribution+of+enhanced+motivation+for+sweetener+consumption.">A mouse model for binge-like sucrose overconsumption: Contribution of enhanced motivation for sweetener consumption.</a> Physiol Behav. 138, 154-164 (2015).</li><li>Fazzino, T. 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=Hyper-palatable+foods:+Development+of+a+quantitative+definition+and+application+to+the+US+Food+System+database.">Hyper-palatable foods: Development of a quantitative definition and application to the US Food System database.</a> Obesity (Silver Spring). 27 (11), 1761-1768 (2019).</li><li>Rosenthal, N., Brown, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+mouse+ascending:+perspectives+for+human-disease+models.">The mouse ascending: perspectives for human-disease models.</a> Nat Cell Biol. 9 (9), 993-999 (2007).</li><li>Yao, Z., 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=A+high-resolution+transcriptomic+and+spatial+atlas+of+cell+types+in+the+whole+mouse+brain.">A high-resolution transcriptomic and spatial atlas of cell types in the whole mouse brain.</a> Nature. 624 (7991), 317-332 (2023).</li><li>Barrera, E., 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=Sex+differences+of+C57BL/6+mice+affect+the+binge-eating+model.">Sex differences of C57BL/6 mice affect the binge-eating model.</a> Neuroscience. , (2024).</li><li>Kraeuter, A. K., Guest, P. C., Sarnyai, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+open+field+test+for+measuring+locomotor+activity+and+anxiety-like+behavior.">The open field test for measuring locomotor activity and anxiety-like behavior.</a> Methods Mol Biol. 1916, 99-103 (2019).</li><li>Avena, N., 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=Evidence+for+sugar+addiction:+behavioral+and+neurochemical+effects+of+intermittent,+excessive+sugar+intake.">Evidence for sugar addiction: behavioral and neurochemical effects of intermittent, excessive sugar intake.</a> Neurosci Biobehav Rev. 32 (1), 20-39 (2008).</li><li>Czyzyk, T. 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=A+model+of+binge-like+eating+behavior+in+mice+that+does+not+require+food+deprivation+or+stress.">A model of binge-like eating behavior in mice that does not require food deprivation or stress.</a> Obesity (Silver Spring). 18 (9), 1710-1717 (2010).</li><li>Mukherjee, 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=The+impact+of+binge-like+palatable+food+intake+on+the+endogenous+glucagon-like+peptide-1+system+in+female+rats.">The impact of binge-like palatable food intake on the endogenous glucagon-like peptide-1 system in female rats.</a> Behav Brain Res. 428, 113869 (2022).</li><li>Sidlo, J., Zaviacic, M., Kvasnicka, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Night+and+day+differences+in+the+food-intake+of+laboratory+rats+Wistar+and+Koletsky+strains.">Night and day differences in the food-intake of laboratory rats Wistar and Koletsky strains.</a> Bratisl Lek Listy. 96 (12), 655-657 (1995).</li><li>Corwin, R. L., Wojnicki, H. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Binge+eating+in+rats+with+limited+access+to+vegetable+shortening.">Binge eating in rats with limited access to vegetable shortening.</a> Curr Protoc Neurosci. Chapter 9 (Unit9.23B), (2006).</li><li>Bailoo, J. D., 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+cage+enrichment+on+behavior,+welfare+and+outcome+variability+in+female+mice.">Effects of cage enrichment on behavior, welfare and outcome variability in female mice.</a> Front Behav Neurosci. 12, 232 (2018).</li><li>Neff, E. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+point+on+thermoneutrality+for+mice.">A point on thermoneutrality for mice.</a> Lab Animal. 49, 169 (2020).</li><li>Osorio, M. 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=Not+feeling+the+heat?+Effects+of+dietary+protein+on+satiation+and+satiety+in+mice+are+not+due+to+its+impact+on+body+temperature.">Not feeling the heat? Effects of dietary protein on satiation and satiety in mice are not due to its impact on body temperature.</a> Appetite. 200, 107421 (2024).</li><li>Qian, S., 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=A+temperature-regulated+circuit+for+feeding+behavior.">A temperature-regulated circuit for feeding behavior.</a> Nat Commun. 13, 4229 (2022).</li><li>Russo, S. J., Nestler, 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=The+brain+reward+circuitry+in+mood+disorders.">The brain reward circuitry in mood disorders.</a> Nat Rev Neurosci. 14 (9), 609-625 (2013).</li><li>Su, 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=Involvement+of+the+nucleus+accumbens+in+chocolate-induced+cataplexy.">Involvement of the nucleus accumbens in chocolate-induced cataplexy.</a> Sci Rep. 10 (1), 4958 (2020).</li><li>Smail-Crevier, R. 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=Binge-like+intake+of+sucrose+reduces+the+rewarding+value+of+sucrose+in+adult+rats.">Binge-like intake of sucrose reduces the rewarding value of sucrose in adult rats.</a> Physiol Behav. 194, 420-429 (2018).</li><li>Sharma, S., Fulton, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diet-induced+obesity+promotes+depressive-like+behavior+that+is+associated+with+neural+adaptations+in+brain+reward+circuitry.">Diet-induced obesity promotes depressive-like behavior that is associated with neural adaptations in brain reward circuitry.</a> Int J Obesity. 37 (3), 382-389 (2013).</li><li>Hu, H., 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=Alternate-day+fasting+ameliorated+anxiety-like+behavior+in+high-fat+diet-induced+obese+mice.">Alternate-day fasting ameliorated anxiety-like behavior in high-fat diet-induced obese mice.</a> J Nutr Biochem. 1241, 09526 (2024).</li><li>Gainey, S. 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=Short-term+high-fat+diet+(HFD)+induced+anxiety-like+behaviors+and+cognitive+impairment+are+improved+with+treatment+by+glyburide.">Short-term high-fat diet (HFD) induced anxiety-like behaviors and cognitive impairment are improved with treatment by glyburide.</a> Front Behav Neurosci. 10, 156 (2016).</li><li>Bahi, A., Dreyer, J. L. <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+chronic+psychosocial+stress+on+'binge-like'+sucrose+intake+in+mice.">Effects of chronic psychosocial stress on 'binge-like' sucrose intake in mice.</a> Prog Neuropsychopharmacol Biol Psychiatry. 120, 110625 (2023).</li><li>Blanco-Gand&#237;a, M. C., Mi&#241;arro, J., Rodr&#237;guez-Arias, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Behavioral+profile+of+intermittent+vs+continuous+access+to+a+high+fat+diet+during+adolescence.">Behavioral profile of intermittent vs continuous access to a high fat diet during adolescence.</a> Behav Brain Res. 368, s111891 (2019).</li><li>Leffa, D. D., 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+palatable+cafeteria+diet+on+cognitive+and+noncognitive+behaviors+and+brain+neurotrophins'+levels+in+mice.">Effects of palatable cafeteria diet on cognitive and noncognitive behaviors and brain neurotrophins' levels in mice.</a> Metab Brain Dis. 30 (4), 1073-1082 (2015).</li><li>Awad, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Altered+reward+processing+following+sucrose+bingeing+in+male+and+female+mice.">Altered reward processing following sucrose bingeing in male and female mice.</a> Nutr Neurosci. 27 (11), 1269-1282 (2024).</li><li>Chen, 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=Ventral+tegmental+area+GABAergic+neurons+induce+anxiety-like+behaviors+and+promote+palatable+food+intake.">Ventral tegmental area GABAergic neurons induce anxiety-like behaviors and promote palatable food intake.</a> Neuropharmacology. 173, 108114 (2020).</li><li>Passeri, 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=Linking+drug+and+food+addiction:+an+overview+of+the+shared+neural+circuits+and+behavioral+phenotype.">Linking drug and food addiction: an overview of the shared neural circuits and behavioral phenotype.</a> Front Behav Neurosci. 17, 1240748 (2023).</li></ol>

The authors have no conflicts of interest to declare.

We used the binge-eating model proposed by Corwin in 2006 as a basis for developing this protocol. However, the present study modified the variable of providing palatable food for 2 h for the CoG8. Instead, we offered palatable food ad libitum to CoG, as it better simulates a reality where we have 24 h access to any food. We also used M&#38;M&#39;s as an HPF because they combine fats and sugars, unlike other binge-eating models that use either fat or sugar separately8</s...

According to data from the World Health Organization1, one in eight people worldwide is obese. Although eating is a physiological necessity, overeating without a physiological need is known to be a factor associated with overweight and obesity2. It is well known that humans prefer palatable foods high in calories, such as fats and sugars, over healthier foods3.
From the perspective of complexity science, eating disorders, particularly binge eating disorder (BED), are multifaceted phenomena that emerge from the interaction of various biological, psychological, and social factors exhibiting emerging behaviors such as cyclic binging patterns, complex compensatory behaviors, and dysfunctional interpersonal relationships4. BED is characterized by the excessive intake of high-calorie foods within a short period, approximately 2 h, according to the Diagnostic and Statistical Manual of Mental Disorders, 5th ed.5 (DSM-V). Additionally, BED is associated with behavioral comorbidities such as anxiety and cravings6,7. The complexity of these disorders requires better experimental models that can capture this interplay of factors and provide a more comprehensive understanding of binge eating behavior and its implications for obesity.
The most used models for binge-like behavior in basic research have primarily been rats. These models typically use limited and intermittent access to high-fat or high-sugar foods to induce binge-like behaviors8,9,10. An alternative approach involves providing palatable food for a short period (2 h) every 8 days, known as a cyclical model, using a highly palatable food (HPF) paste containing a mix of fats and sugars11. Another method presents the HPF as cookies unpredictably12. In mouse models, binge-like behaviors are often studied using the same cyclical model13. Another study with mice uses limited access to sucrose to induce binge-like behaviors14.
Despite extensive research on binge-like eating behaviors in rats, models for binge eating in mice remain limited. This study aims to propose a binge-like eating model using M&#38;M&#39;s (hereafter referred to as &#34;HPF&#34;) as an HPF according to the nutritional criteria of HPF proposed by Fazzino and colleagues15. Additionally, we aim to evaluate the rewarding properties of the HPF based on whether they are presented continuously or intermittently. In our research, we aimed to observe similarities between specific diagnostic DSM-V criteria for binge eating in humans within a murine model: consuming food within a short period (2 h), ingesting a large amount of food than usual, eating substantial amount despite being in a state of satiety, and experiencing binge episodes at the least twice a week.
The use of laboratory mouse models is an invaluable tool in biomedical research, especially for studying human diseases, as mice share 99% of their genes with humans16. Utilizing mice also offers significant advantages in understanding transcriptomic information and modifying therapeutic targets related to cellular functions and neural circuits associated with various diseases17.
Therefore, this study proposes a continuous and intermittent access model to M&#38;M&#39;s (an HPF made of fat and sugar) to observe binge-like eating in C57BL/6 mice without standard chow or water deprivation. This model is novel and necessary for biomedical research, as it represents a better approach to studying these complex problems. Standardizing animal models is essential to obtain reproducible and comparable results, which is fundamental to advancing translational research and developing effective therapeutic interventions for BED and obesity. The approach described here will expand the scope of binge-like eating behavior research in future studies, facilitating the testing of various drugs as potential therapeutic targets for BED. The implementation of more realistic and standardized models in mice will allow for a better understanding of the complex dynamics involved in eating disorders and their metabolic consequences, thus offering new alternatives for the treatment and prevention of BED.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>ANY-maze Video Tracking Software</td>
			<td>Stoelting Co.</td>
			<td>4.73 version</td>
			<td></td>
		</tr>
		<tr>
			<td>C270 HD Webcam</td>
			<td>Logitech</td>
			<td>C270 HD</td>
			<td>It is not necessary to use a specific video recorder; any webcam or camcorder with satisfactory image quality and resolution will suffice.</td>
		</tr>
		<tr>
			<td>Gloves Ambiderm (black)</td>
			<td>Ambiderm</td>
			<td>7.50222E+12</td>
			<td></td>
		</tr>
		<tr>
			<td>GraphPad Prism 9</td>
			<td>GraphPad</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Laboratory Rodent Diet 5001</td>
			<td>LabDiet</td>
			<td>1320</td>
			<td>https://di.facmed.unam.mx/comisiones/Composici%C3%B3n%20del%20alimento%20Laboratory%20Rodent%20Diet%205001.pdf</td>
		</tr>
		<tr>
			<td>M&#38;Ms 43.8g (Brown packaging)</td>
			<td>M&#38;M&#180;s&#160;</td>
			<td></td>
			<td>Nutritional content per 100 : 480 kcal, 19g of fat, 70 g of carbohydrates, 5.1 g of protein, 0.13 g of saltIngredients:&#160;sugar, cocoa mass, skimmed&#160;milk&#160;powder, cocoa butter,&#160;lactose, starch,&#160;milk&#160;fat, palm fat, glucose syrup, shea fat, stabiliser (gum arabic), dextrin, glazing agents (beeswax, carnauba wax), colours (E100, carmine, E132, E133, E150a, E150c, E150d, E153, E160a, E160e, E162, E163, E170), beetroot concentrate, emulsifiers (soya&#160;lecithin, E445), salt, flavourings, palm kernel oil, antioxidant (E306). (May contain:&#160;peanut, hazelnut, almond). Milk chocolate contains milk solids 14% minimum.&#160;Milk chocolate contains vegetable fats in addition to cocoa butter.</td>
		</tr>
		<tr>
			<td>Open Field maze&#160;</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Polypropylene Mice Cage</td>
			<td>Orchid Scientific</td>
			<td>SMP 01</td>
			<td></td>
		</tr>
		<tr>
			<td>Rodent drinkers</td>
			<td>Sunnypet</td>
			<td>SP-3656</td>
			<td></td>
		</tr>
		<tr>
			<td>Uline Balanza-220 g x 0.01 g</td>
			<td>unike.mx</td>
			<td>H-9884</td>
			<td></td>
		</tr>
		<tr>
			<td>UniMask4</td>
			<td>Uniseal</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Plastic bottles</td>
			<td>unike.mx</td>
			<td>S-14487</td>
			<td></td>
		</tr>
		<tr>
			<td>Sanitary Bed, Sawdust for Animals</td>
			<td>BIOINVERT</td>
			<td>No number</td>
			<td>10 kg</td>
		</tr>
	</tbody>
</table>

intermittent binge-intake model in mice

Obesity affects one in eight individuals globally. Overeating, especially high-calorie foods, plays a significant role in obesity. Binge eating disorder (BED) is a complex condition caused by a combination of biological, psychological, and social factors. It involves excessive consumption of high-calorie foods in a short period and is often linked to anxiety and cravings.
Here, we present a protocol employing continuous and intermittent access to a new highly palatable food (HPF) -- M&amp;M&#39;s -- to develop a mouse model for investigating binge eating disorder (BED). The HPF, chosen for its high fat and sugar content, represents an optimal food source to study due to its strong palatability, which makes it particularly suited for examining compulsive eating behaviors. Using C57BL/6 mice, we provided continuous or intermittent access to M&amp;M&#39;s while allowing unrestricted access to standard chow and water. By the 8th day, the mice in the intermittent access group exhibited pronounced binge-eating behaviors, which persisted through the 26th day. These mice also consumed significantly more calories -- predominantly from the confectionary -- than those in the continuous access and control groups. The contrast between continuous and intermittent access underscores the critical role of feeding schedules in promoting the overconsumption of palatable foods.
Furthermore, behavioral assessments revealed intermittent access to the HPF-induced anxiety-like behaviors, highlighting the psychological impact of access patterns on both eating behavior and emotional states. By incorporating these two distinct feeding paradigms, this study offers valuable insights into how the availability of highly palatable foods can exacerbate binge-eating tendencies. This model provides a more realistic approach to studying binge-eating behaviors and their metabolic consequences. It highlights the importance of standardized models in biomedical research. Our findings offer insights into the physiological and neural mechanisms underlying BED, which could pave the way for developing effective therapeutic interventions for BED and obesity.

Using HPF, we successfully established a binge-eating model in C57BL/6 mice. By day 8, binge-eating behavior (consuming excessive food for 2 h) was firmly established and maintained through day 26 (Figure 1A). During the intermittent sessions, the IG group exhibited significantly higher total kcal consumption (from both standard chow and the HPF than the CG and CoG) groups (Figure 1A, ### p &#60; 0.0001, *** p &#60; 0.0001, ** p &#60; 0.001, Kruskal-Wallis test)...

Author Spotlight: Accessible M&amp;M-Based Mouse Model for Investigating Binge Eating Disorder - Insights into Eating Behaviors, Anxiety, and Neural Mechanisms

A binge-eating model was established in mice using intermittent access to M&amp;M's (a highly palatable food made of fat and sugar). Mice with intermittent access to this high-fat, high-sugar food showed stress-like behaviors, increased caloric intake, and a preference for that food over standard chow compared to mice with continuous or no access to the food.

Intermittent Binge-Intake Model in Mice

Obesity affects one in eight individuals globally. Overeating, especially high-calorie foods, plays a significant role in obesity. Binge eating disorder ...

Research

JoVE Journal

Behavior

609 Views.  Universidad Nacional Autónoma de México (UNAM). Dit onderzoek onderzoekt de invloed van patronen in de beschikbaarheid van voedsel op eetbuigedrag en angstachtig gedrag bij eetbuistoornissen, of BED. Met behulp van een nieuw M&M's-muismodel vergelijken we de effecten van continue versus intermitterende toegang tot smakelijk voedsel. Het doel is om toegankelijke modellen te ontwikkelen voor fundamenteel onderzoek naar eetbuienstoornissen.Ons protocol biedt een snel, eenvoudig en toegankelijk M&M-geba...

Video: Auteur Spotlight: Toegankelijk M&M-gebaseerd muismodel voor het onderzoeken van eetbuistoornis - Inzichten in eetgedrag, angst en neurale mechanismen

Trace Fear Conditioning in Mice

In this experiment we present a technique to measure learning and memory. In the trace fear conditioning protocol presented here there are five pairings between a neutral stimulus and an unconditioned stimulus. There is a 20 sec trace period that separates each conditioning trial. On the following day freezing is measured during presentation of the conditioned stimulus (CS) and trace period. On the third day there is an 8 min test to measure contextual memory. The representative results are from mice that were presented with the aversive unconditioned stimulus (shock) compared to mice that received the tone presentations without the unconditioned stimulus. Trace fear conditioning has been successfully used to detect subtle learning and memory deficits and enhancements in mice that are not found with other fear conditioning methods. This type of fear conditioning is believed to be dependent upon connections between the medial prefrontal cortex and the hippocampus. One current controversy is whether this method is believed to be amygdala-independent. Therefore, other fear conditioning testing is needed to examine amygdala-dependent learning and memory effects, such as through the delay fear conditioning.

In the following experiment we describe a protocol for trace fear conditioning in mice. This type of associative memory includes a trace period that separates the neutral stimulus and the unconditioned stimulus.

In this experiment we present a technique to measure learning and memory. In the trace fear conditioning protocol presented here there are five pairings ...

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 ...

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 ...

Quantifying Social Motivation in Mice Using Operant Conditioning

In this protocol, social motivation is measured in mice through a pair of operant conditioning paradigms. To conduct the experiments, two-chambered shuttle boxes were equipped with two operant levers (left and right) and a food receptacle in one chamber, which was then divided from the second chamber by an automated guillotine door covered by a wire grid. Different stimulus mice, rotated across testing days, served as a social stimulus behind the wire grid, and were only visible following the opening of the guillotine door. Test mice were trained to lever press in order to open the door and gain access to the stimulus partner for 15 sec. The number of lever presses required to obtain the social reward progressively increased on a fixed schedule of 3. Testing sessions ended after test mice stopped lever pressing for 5 consecutive minutes. The last reinforced ratio or breakpoint can be used as a quantitative measure of social motivation. For the second paradigm, test mice were trained to discriminate between left and right lever presses in order to obtain either a food reward or the social reward. Mice were rewarded for every 3 presses of each respective lever. The number of food and social rewards can be compared as a measurement of the value placed upon each reward. The ratio of each reward type can also be compared between mouse strains and the change in this ratio can be monitored within testing sessions to measure satiation with a given reward type. Both of these operant conditioning paradigms are highly useful for the quantification of social motivation in mouse models of autism and other disorders of social behavior.

This article describes a new protocol for the quantitative measurement of social motivation in mice using operant conditioning for a social reward. The protocol is useful for the measurement of social motivation in mouse models of autism and other disorders of social behavior.

In this protocol, social motivation is measured in mice through a pair of operant conditioning paradigms. To conduct the experiments, two-chambered ...

Assessing Activity-based Anorexia in Mice

Rodents develop activity-based anorexia (ABA) when exposed to a restricted feeding schedule and allowed free access to a running wheel. These conditions lead to a life-threatening reduction in body weight. However, rodents exposed to only one of these conditions ultimately adapt to re-establish normal body weight. Although increased running coupled with reduction in voluntary food intake appear paradoxical under ABA conditions, ABA behavior is observed across numerous mammalian species. 
The ABA paradigm provides an animal model for anorexia nervosa (AN), an eating disorder with severe dysregulation of appetite-behavior. Subjects are singly housed with free access to a running wheel. Each day, the subject is offered food for a limited amount of time. During the course of the experiment, a subject's body weight decreases from high activity and low caloric intake. The duration of the study varies based on how long food is offered daily, the type of food offered, the strain of mouse, if drugs are being tested, and environmental factors.
A lack of effective pharmacological treatments for AN patients, their low quality of life, high cost of treatment, and their high mortality rate indicate the urgency to further research AN. We provide a basic outline for performing ABA experiments with mice, offering a method to investigate AN-like behavior in order to develop novel therapies. This protocol is optimized for use in Balb/cJ mice, but can easily be manipulated for other strains, providing great flexibility in working with different questions, especially related to genetic factors of ABA.

Mice individually housed with a running wheel while given limited access to food develop reductions in food consumption and increase activity on the running wheel. This experimental phenomenon is called activity-based anorexia. This paradigm provides an experimental tool for studying the neurobiology and behaviors underlying aspects of anorexia nervosa.

Rodents develop activity-based anorexia (ABA) when exposed to a restricted feeding schedule and allowed free access to a running wheel. These conditions ...

Measuring Active and Passive Tameness Separately in Mice

Domesticated animals such as dogs and laboratory mice show a high level of tameness, which is important for humans to handle them easily. Tameness has two behavioral components: a reluctance to avoid humans (passive tameness) and a motivation to approach humans (active tameness). To quantify these components in mice, we previously developed behavioral tests for active tameness, passive tameness, and the willingness to stay on a human hand, each designed to be completed within 3 min. The data obtained were used for selective breeding, with a large number of mice analyzed per generation. The active tameness test measures the movement of the mouse toward a human hand and the contact it engages in. The passive tameness test measures the duration of time that a mouse tolerates human touch. In the stay-on-hand test, a mouse is placed on a human hand and touched slowly using the thumb of that hand; the duration of time that the animal remains on the hand is measured. Here, we describe the test set-up and apparatus, explain the procedures, and discuss the appropriate data analysis. Finally, we explain how to interpret the results.

Tameness in animals includes a reduction of avoidance responses to humans (passive tameness) and an increase in active approaches to humans (active tameness). Here, we describe detailed protocols for three behavioral tests (active tameness, passive tameness, and stay-on-hand tests) to separately measure the active and passive tameness of mice.

Domesticated animals such as dogs and laboratory mice show a high level of tameness, which is important for humans to handle them easily. Tameness has two ...

Evaluating Skilled Prehension in Mice Using an Auto-Trainer

We describe a method to introduce na&#239;ve mice to a novel prehension (reach-to-grasp) task. Mice are housed singly in cages with a frontal slot that permits the mouse to reach out of its cage and retrieve food pellets. Minimal food restriction is employed to encourage the mice to perform the food retrieval from the slot. As the mice begin to associate coming to the slot for food, the pellets are manually pulled away to stimulate extension and pronation of their paw to grasp and retrieve the pellet through the frontal slot. When the mice begin to reach for the pellets as they arrive at the slot, the behavioral assay can be performed by measuring the rate at which they successfully grasp and retrieve the desired pellet. They are then introduced to an auto-trainer that automates both the process of providing food pellets for the mouse to grasp, and the recording of successful and failed reaching and grasping attempts. This allows for the collection of reaching data for multiple mice with minimal effort, to be used in experimental analysis as appropriate.

Method to assess the impact of training on motor skills is a useful tool. Unfortunately, most behavioral assessments can be labor intensive and/or expensive.We describe here a robotic method of assessing prehension (reach-to-grasp) skill in mice.

We describe a method to introduce na&#239;ve mice to a novel prehension (reach-to-grasp) task. Mice are housed singly in cages with a frontal slot that ...

Assessment of Memory Function in Pilocarpine-induced Epileptic Mice

Cognitive impairment is one of the most common comorbidities in temporal lobe epilepsy. To recapitulate epilepsy-associated cognitive decline in an animal model of epilepsy, we generated pilocarpine-treated chronic epileptic mice. We present a protocol for three different behavioral tests using these epileptic mice: novel object location (NL), novel object recognition (NO), and pattern separation (PS) tests to evaluate learning and memory for places, objects, and contexts, respectively. We explain how to set the behavioral apparatus and provide experimental procedures for the NL, NO, and PS tests following an open field test that measures the animals&#8217; basal locomotor activities. We also describe the technical advantages of the NL, NO, and PS tests with respect to other behavioral tests for assessing memory function in epileptic mice. Finally, we discuss possible causes and solutions for epileptic mice failing to make 30 s of good contact with the objects during the familiarization sessions, which is a critical step for successful memory tests. Thus, this protocol provides detailed information about how to assess epilepsy-associated memory impairments using mice. The NL, NO, and PS tests are simple, efficient assays that are appropriate for the evaluation of different kinds of memory in epileptic mice.

This article presents experimental procedures for assessing memory impairments in pilocarpine-induced epileptic mice. This protocol can be used to study the pathophysiologic mechanisms of epilepsy-associated cognitive decline, which is one of the most common comorbidities in epilepsy.

Cognitive impairment is one of the most common comorbidities in temporal lobe epilepsy. To recapitulate epilepsy-associated cognitive decline in an animal ...

Chronic Stress Shifts Effort-Related Choice Behavior in a Y-Maze Barrier Task in Mice

Mood disorders, including major depressive disorder, can be precipitated by chronic stress. The Y-maze barrier task is an effort-related choice test that measures motivation to expend effort and obtain reward. In mice, chronic stress exposure significantly impacts motivation to work for a higher value reward when a lesser value reward is freely available compared to unstressed mice. Here we describe the chronic corticosterone administration paradigm, which produces a shift in effortful responding in the Y-maze barrier task. In the Y-maze task, one arm contains 4 food pellets, while the other arm contains only 2 pellets. After mice learn to select the high reward arm, barriers with progressively increasing height are then introduced into the high reward arm over multiple test sessions. Unfortunately, most chronic stress paradigms (including corticosterone and social defeat) were developed in male mice and are less effective in female mice. Therefore, we also discuss chronic non-discriminatory social defeat stress (CNSDS), a stress paradigm we developed that is effective in both male and female mice. Repeating results with multiple distinct chronic stressors in male and female mice combined with increased usage of translationally relevant behavior tasks will help to advance the understanding of how chronic stress can precipitate mood disorders.

The Y-maze barrier task is a behavior test that examines motivation to expend effort for reward. Here, we discuss testing multiple well-validated chronic stressors including chronic corticosterone and social defeat stress with this behavior, as well as the novel chronic non-discriminatory social defeat stress (CNSDS), which is effective in females.

Mood disorders, including major depressive disorder, can be precipitated by chronic stress. The Y-maze barrier task is an effort-related choice test that ...

Handling Techniques to Reduce Stress in Mice

Laboratory animals are subjected to multiple manipulations by scientists or animal care providers. The stress this causes can have profound effects on&#160;animal well-being and can also be a confounding factor for experimental variables such as anxiety measures. Over the years, handling techniques that minimize handling-related stress have been developed with a particular focus on rats, and little attention to mice. However, it has been shown that mice can be habituated to manipulations using handling techniques. Habituating mice to handling reduces stress, facilitates routine handling, improves animal wellbeing, decreases data variability, and improves experimental reliability. Despite beneficial effects of handling, the tail-pick up approach, which is particularly stressful, is still widely used. This paper provides a detailed description and demonstration of a newly developed mouse-handling technique intended to minimize the stress experienced by the animal during human interaction. This manual technique is performed over 3 days (3D-handling technique) and focuses on the animal&#39;s capacity to habituate to the experimenter. This study also shows the effect of previously established tunnel handling techniques (using a polycarbonate tunnel) and the tail-pick up technique. Specifically studied are their effects on anxiety-like behaviors, using behavioral tests (Elevated-Plus Maze and Novelty Suppressed Feeding), voluntary interaction with experimenters and physiological measurement (corticosterone levels). The 3D-handling technique and the tunnel handling technique reduced anxiety-like phenotypes. In the first experiment, using 6-month-old male mice, the 3D-handling technique significantly improved experimenter interaction. In the second experiment, using 2.5-month-old female, it reduced corticosterone levels. As such, the 3D-handling is a useful approach in scenarios where interaction with the experimenter is required or preferred, or where tunnel handling may not be possible during the experiment.

This paper describes a handling technique in mice, the 3D-handling technique, which facilitates routine handling by reducing anxiety-like behaviors and presents details on two existing related techniques (tunnel and tail handling).

Laboratory animals are subjected to multiple manipulations by scientists or animal care providers. The stress this causes can have profound effects ...

Intermittent Binge-Intake Model in Mice

Samenvatting

Meer video's verkennen

Hoofdstukken in deze video