This work was supported by the Japanese Society for the Promotion of Science, Kakenhi grants 16H06543 and 21H05296 to S.T.

All procedures were approved by the Doshisha University Institutional Animal Care and Use Committees. Three male Long-Evans rats, aged between 24 and 28 weeks (at the start of behavioral training), with body weights of 300-350 g, were used for the present study. The rats were housed individually in home cages (20 cm x 25 cm x 23 cm) on a 12 h light/12 h dark schedule, with the light period starting at 08:00 am. The animals were obtained from a commercial source (see Table of Materials).
1. Maze system components
NOTE: The maze system (including all the components, steps 1.1-1.5) (see Table of Materials) must be mounted in a shielded room covered with copper mesh (4 m x 5 m for rats and 1.8 m&#160;&#215; 3.0 m for mice) for simultaneous use of electrophysiological neural activity recording. The maze needs to be elevated at a fixed height from the floor (55 cm for rats and 34 cm for mice).
<ol>
	<li>Punching board
	<ol>
		<li>Place the aluminum punching board on the shield room floor (dimensions of the punching board: 360 cm x 480 cm x 1.2 cm for rats; 160 cm x 160 cm x 1.2 cm for mice) (Figure 1F,G). 
		NOTE: The experimenter can stand on the board.</li>
		<li>Equip the punching board with a grid of equally spaced holes (for both rats and mice, 25 mm hole spacing and 6 mm hole diameter) (Figure 2C). 
		NOTE: These holes enable the placement of highly repeatable mazes (Figure 2D).</li>
	</ol>
	</li>
	<li>Tower with baseplate
	<ol>
		<li>Develop a tower with a baseplate made of aluminum to form pathways of a fixed height (the dimensions of the stem part of the tower are 55 cm&#160;&#215; 6 cm&#160;&#215; 2 cm for rats and 34 cm&#160;&#215; 1.3 cm&#160;&#215; 1.3 cm for mice) (Figure 1A).</li>
		<li>Use the baseplate to fix the position of the maze parts (the dimensions of the baseplate are 18 cm&#160;&#215; 11 cm&#160;&#215; 0.5 cm for rats and 12 cm&#160;&#215; 7 cm&#160;&#215; 0.3 cm for mice).</li>
		<li>Equip the baseplate with protrusions to connect a grid of equally spaced holes in the punching board (the protrusion diameter is 6 mm) (Figure 2B).</li>
		<li>Use the holes to connect components such as feeders, movable walls, and treadmills (see Table of Materials) equipped with towers with baseplates. 
		NOTE: For rats, the baseplate had four protrusions (length of 8 mm) (Figure 1F) inserted into the holes in the punching board. For mice, the baseplate was too light to support the pathway, so bolts were inserted into the holes (bolt lengths were 14 mm) (Figure 1G).</li>
	</ol>
	</li>
	<li>Maze pathway 
	NOTE: The commercially available pathway (49 cm&#160;&#215; 10 cm for rats and 39 cm&#160;&#215; 5 cm for mice) was made of polyvinyl chloride (thickness of 5 mm for rats and 3 mm for mice) (see Table of Materials).
	<ol>
		<li>Construct the smallest part of the maze by placing the pathway in the upper part of the tower (Figure 1B).</li>
		<li>Design the upper part of the tower to conform the dimensions of bottom side of the pathway (dimensions of the upper part of the tower are 48 cm&#160;&#215; 8 cm&#160;&#215; 1 cm for rats and 21.9 cm&#160;&#215; 3.9&#160;cm&#160;&#215; 0.3 cm for mice). To fix the pathway to the tower, place it on top.</li>
		<li>Provide side barriers made of polyvinyl chloride to prevent animals from falling (45 mm for rats and 30 mm for mice). 
		NOTE: Several patterns are available for connecting the pathways in various ways, such as parts with only one side barrier removed. 3D models of the pathway parts are available (https://github.com/TakahashiLab/ReconfigurableMazeParts) and can be printed using a 3D printer (see&#160;&#8203;Table of Materials).</li>
	</ol>
	</li>
	<li>Accompanying parts 
	NOTE: The parts required for behavioral experiments can be implemented by attaching a common baseplate with the pathway.
	<ol>
		<li>Place feeders on the side of any pathway to change the site of the reward (Figure 1C). 
		NOTE: Animals poking the feeders are detected by the shut-off sensors (see Table of Materials).</li>
		<li>Place movable walls in the gaps between the pathways to force animals to guide the direction of movement (Figure 1D). 
		NOTE: For rats, when the movable wall is raised, the height of the wall is 90 cm from the floor and 29.5 cm from the side barriers of the pathway. When the movable wall is lowered, the height of the wall is 54 cm from the floor and -5.5 cm from the side barriers of the pathway. For mice, when the movable wall is raised, the height of the wall is 55 cm from the floor and 17 cm from the side barriers of the pathway. When the movable wall is lowered, the height of the wall is 35 cm from the floor and -3 cm from the side barriers of the pathway.</li>
		<li>Place treadmills with pathways to force running delays at fixed positions (Figure 1E).</li>
	</ol>
	</li>
	<li>Control box 
	NOTE: Control each part automatically via the control box (Figure 1H) (see Table of Materials).
	<ol>
		<li>Use a microcontroller to receive signals from the treadmills and feeders via the control box. 
		NOTE: The shut-off sensor on the feeder and the number of treadmill rotations can be detected.</li>
		<li>Use a microcontroller to send activation signals to the treadmills, feeders, and movable wall actuators according to a set task schedule via the control box. Individually control the dispensing and discarding of pellets, and the raising and lowering of the movable wall.</li>
	</ol>
	</li>
</ol>
2. Evaluation of special navigation of rodents in the reconfigurable maze
NOTE: An animal behavior experiment was conducted using the reconfigurable maze (developed in step 1).
<ol>
	<li>Example construction of a maze 
	NOTE: An example of how to assemble a T-shaped maze for rats used in the delayed-alternation task experiment is provided in Figure 3.
	<ol>
		<li>Insert towers with baseplates into the punching board to form a T-shaped framework (Figure 3A).</li>
		<li>Attach pathways to the upper part of the towers (Figure 3B).</li>
		<li>Replace the pathway in the delayed area with a treadmill (Figure 3C). 
		NOTE: The treadmill can be replaced by a pathway of the same height and length.</li>
		<li>Attach feeders to each edge of the maze (Figure 3D).</li>
		<li>Attach movable walls to the left and right branches (Figure 3E). 
		NOTE: Ensure the animal&#39;s&#160;paw&#160;and tail do not get caught in the gaps between sections. 
		&#160;</li>
	</ol>
	</li>
	<li>Animals
	<ol>
		<li>Ensure the body weight of the rats remains between 300 and 350 g, and conduct all behavioral experiments during the daytime.</li>
	</ol>
	</li>
	<li>Task execution
	<ol>
		<li>Start-up and connect the control box, microcontroller, and PC.</li>
		<li>Write a program to set up the task schedule and receive the parameters needed for the experiment.</li>
		<li>Write the program to the microcontroller and execute a task. 
		NOTE: The example of a set task schedule written in C using a microcontroller board is available in a public repository (https://github.com/TakahashiLab/ReconfigurableMazeExample).</li>
	</ol>
	</li>
	<li>Behavioral experiment
	<ol>
		<li>Construct the desired maze shape (step 2.1).</li>
		<li>Move the rats from the home cages and place them in the arbitrary position of the maze.</li>
		<li>Allow the rats to freely explore the constructed maze for 10 min to habituate.</li>
		<li>Set up a program to perform the delayed alternation task with the treadmill23,24. 
		NOTE: The parameters required for the experiment can be obtained automatically by the program settings (e.g., number of poking times, duration of the experiment, treadmill speed, etc.).</li>
		<li>Change the shape of the maze if necessary.</li>
		<li>Place the rats at the arbitrary position in the maze and execute the training or test of the delayed alternation task. 
		NOTE: In the present study, training sessions were conducted with a gradually increasing delay time and test sessions (with a 5 s delay time).</li>
		<li>Return the rats to the home cage after each task.</li>
		<li>Wipe the maze thoroughly with 70% ethanol after each rat and wait at least 5 min before using the maze again. 
		&#8203;NOTE: The parts of the pathway can be detached from the tower so that they can be thoroughly wiped clean of odors and dirt.</li>
	</ol>
	</li>
</ol>
3. Behavioral performance and data analysis
<ol>
	<li>Animal trajectory
	<ol>
		<li>Record animal behavior during the delayed alternation task with a ceiling-mounted digital video camera (see Table of Materials). 
		NOTE: By placing the camera on the ceiling, the experimenter can constantly record the animals&#39; movements as they run around the maze during the task.</li>
		<li>Track the running trajectories using markerless pose estimation software25 (see Table of Materials) based on images captured at 50 frames/s.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Olton, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mazes,+maps,+and+memory.">Mazes, maps, and memory.</a> American Psychologist. 34 (7), 583-596 (1979).</li><li>Small, W. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+Study+of+the+Mental+Processes+of+the+Rat.">Experimental Study of the Mental Processes of the Rat.</a> The American Journal of Psychology. 12 (2), 206-239 (1901).</li><li>Jaffard, R., Dubois, M., Galey, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Memory+of+a+choice+direction+in+a+T+maze+as+measured+by+spontaneous+alternation+in+mice:+Effects+of+intertrial+interval+and+reward.">Memory of a choice direction in a T maze as measured by spontaneous alternation in mice: Effects of intertrial interval and reward.</a> Behavioural Processes. 6 (1), 11-21 (1981).</li><li>Pellow, S., Chopin, P., File, S. E., Briley, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Validation+of+open:closed+arm+entries+in+an+elevated+plus-maze+as+a+measure+of+anxiety+in+the+rat.">Validation of open:closed arm entries in an elevated plus-maze as a measure of anxiety in the rat.</a> Journal of Neuroscience Methods. 14 (3), 149-167 (1985).</li><li>Olton, D. S., Collison, C., Werz, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatial+memory+and+radial+arm+maze+performance+of+rats.">Spatial memory and radial arm maze performance of rats.</a> Learning and Motivation. 8 (3), 289-314 (1977).</li><li>Olton, D. 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+radial+arm+maze+as+a+tool+in+behavioral+pharmacology.">The radial arm maze as a tool in behavioral pharmacology.</a> Physiology &amp; Behavior. 40 (6), 793-797 (1987).</li><li>Baeg, E. 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=Dynamics+of+population+code+for+working+memory+in+the+prefrontal+cortex.">Dynamics of population code for working memory in the prefrontal cortex.</a> Neuron. 40 (1), 177-188 (2003).</li><li>Redish, A. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vicarious+trial+and+error.">Vicarious trial and error.</a> Nature Reviews Neuroscience. 17 (3), 147-159 (2016).</li><li>Walf, A. A., Frye, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+use+of+the+elevated+plus+maze+as+an+assay+of+anxiety-related+behavior+in+rodents.">The use of the elevated plus maze as an assay of anxiety-related behavior in rodents.</a> Nature Protocols. 2 (2), 322-328 (2007).</li><li>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=Learning+about+cognition+risk+with+the+radial-arm+maze+in+the+developmental+neurotoxicology+battery.">Learning about cognition risk with the radial-arm maze in the developmental neurotoxicology battery.</a> Neurotoxicology and Teratology. 52, 88-92 (2015).</li><li>Crawley, J. N., Paylor, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+proposed+test+battery+and+constellations+of+specific+behavioral+paradigms+to+investigate+the+behavioral+phenotypes+of+transgenic+and+knockout+mice.">A proposed test battery and constellations of specific behavioral paradigms to investigate the behavioral phenotypes of transgenic and knockout mice.</a> Hormones and Behavior. 31 (3), 197-211 (1997).</li><li>d'Isa, R., Comi, G., Leocani, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Apparatus+design+and+behavioural+testing+protocol+for+the+evaluation+of+spatial+working+memory+in+mice+through+the+spontaneous+alternation+T-maze.">Apparatus design and behavioural testing protocol for the evaluation of spatial working memory in mice through the spontaneous alternation T-maze.</a> Scientific Reports. 11 (1), 21177 (2021).</li><li>Gill, P. R., Mizumori, S. J. Y., Smith, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hippocampal+episode+fields+develop+with+learning.">Hippocampal episode fields develop with learning.</a> Hippocampus. 21 (11), 1240-1249 (2011).</li><li>Takahashi, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hierarchical+organization+of+context+in+the+hippocampal+episodic+code.">Hierarchical organization of context in the hippocampal episodic code.</a> eLife. 2, 00321 (2013).</li><li>Lipton, P. A., White, J. A., Eichenbaum, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Disambiguation+of+overlapping+experiences+by+neurons+in+the+medial+entorhinal+cortex.">Disambiguation of overlapping experiences by neurons in the medial entorhinal cortex.</a> The Journal of Neuroscience. 27 (21), 5787-5795 (2007).</li><li>Muller, R. U., Kubie, 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=The+Effects+of+Changes+in+the+Environment+on+the+Spatial+Firing+of+Hippocampal+Complex-Spike+Cells.">The Effects of Changes in the Environment on the Spatial Firing of Hippocampal Complex-Spike Cells.</a> The Journal of Neuroscience. 7 (7), 1951-1968 (1987).</li><li>Knierim, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+interactions+between+local+surface+cues,+distal+landmarks,+and+intrinsic+circuitry+in+hippocampal+place+cells.">Dynamic interactions between local surface cues, distal landmarks, and intrinsic circuitry in hippocampal place cells.</a> The Journal of Neuroscience. 22 (14), 6254-6264 (2002).</li><li>Fyhn, M., Hafting, T., Treves, A., Moser, M. B., Moser, E. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hippocampal+remapping+and+grid+realignment+in+entorhinal+cortex.">Hippocampal remapping and grid realignment in entorhinal cortex.</a> Nature. 446 (7132), 190-194 (2007).</li><li>Maaswinkel, H., Whishaw, I. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Homing+with+locale,+taxon,+and+dead+reckoning+strategies+by+foraging+rats:+sensory+hierarchy+in+spatial+navigation.">Homing with locale, taxon, and dead reckoning strategies by foraging rats: sensory hierarchy in spatial navigation.</a> Behavioural Brain Research. 99 (2), 143-152 (1999).</li><li>Wallace, D. G., Gorny, B., Whishaw, I. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rats+can+track+odors,+other+rats,+and+themselves:+implications+for+the+study+of+spatial+behavior.">Rats can track odors, other rats, and themselves: implications for the study of spatial behavior.</a> Behavioural Brain Research. 131 (1-2), 185-192 (2002).</li><li>Carvell, G. E., Simons, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biometric+analyses+of+vibrissal+tactile+discrimination+in+the+rat.">Biometric analyses of vibrissal tactile discrimination in the rat.</a> The Journal of Neuroscience. 10 (8), 2638-2648 (1990).</li><li>Hoshino, 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=The+reconfigurable+maze+provides+flexible,+scalable,+reproducible,+and+repeatable+tests.">The reconfigurable maze provides flexible, scalable, reproducible, and repeatable tests.</a> iScience. 23 (1), 100787 (2019).</li><li>Salz, D. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Time+cells+in+hippocampal+area+CA3.">Time cells in hippocampal area CA3.</a> The Journal of Neuroscience. 36 (28), 7476-7484 (2016).</li><li>Kraus, B. 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=During+running+in+place,+grid+cells+integrate+elapsed+time+and+distance+run.">During running in place, grid cells integrate elapsed time and distance run.</a> Neuron. 88 (3), 578-589 (2015).</li><li>Mathis, 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=DeepLabCut:+markerless+pose+estimation+of+user-defined+body+parts+with+deep+learning.">DeepLabCut: markerless pose estimation of user-defined body parts with deep learning.</a> Nature Neuroscience. 21 (9), 1281-1289 (2018).</li><li>Frank, L. M., Brown, E. N., Wilson, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trajectory+encoding+in+the+hippocampus+and+entorhinal+cortex.">Trajectory encoding in the hippocampus and entorhinal cortex.</a> Neuron. 27 (1), 169 (2000).</li><li>Gothard, K. M., Skaggs, W. E., McNaughton, B. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamics+of+mismatch+correction+in+the+hippocampal+ensemble+code+for+space:+interaction+between+path+integration+and+environmental+cues.">Dynamics of mismatch correction in the hippocampal ensemble code for space: interaction between path integration and environmental cues.</a> The Journal of Neuroscience. 16 (24), 8027-8040 (1996).</li><li>Greenhouse, S. W., Geisser, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+methods+in+the+analysis+of+profile+data.">On methods in the analysis of profile data.</a> Psychometrika. 24 (2), 95-112 (1959).</li><li>Kraus, B. J., Robinson, R. J., White, J. A., Eichenbaum, H., Hasselmo, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hippocampal+&amp;#34;time+cells&amp;#34;:+time+versus+path+integration.">Hippocampal &amp;#34;time cells&amp;#34;: time versus path integration.</a> Neuron. 78 (6), 1090 (2013).</li><li>Lenck-Santini, P. -. P., Save, E., Poucet, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Place-cell+firing+does+not+depend+on+the+direction+of+turn+in+a+Y-maze+alternation+task.">Place-cell firing does not depend on the direction of turn in a Y-maze alternation task.</a> European Journal of Neuroscience. 13 (5), 1055-1058 (2001).</li><li>Pastalkova, E., Itskov, V., Amarasingham, A., Buzs&#225;ki, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Internally+generated+cell+assembly+sequences+in+the+rat+hippocampus.">Internally generated cell assembly sequences in the rat hippocampus.</a> Science. 321 (5894), 1322-1327 (2008).</li><li>O'Keefe, J., Dostrovsky, 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+hippocampus+as+a+spatial+map.+Preliminary+evidence+from+unit+activity+in+the+freely-moving+rat.">The hippocampus as a spatial map. Preliminary evidence from unit activity in the freely-moving rat.</a> Brain Research. 34 (1), 171-175 (1971).</li><li>Lever, C., Burton, S., Jeewajee, A., O'Keefe, J., Burgess, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Boundary+vector+cells+in+the+subiculum+of+the+hippocampal+formation.">Boundary vector cells in the subiculum of the hippocampal formation.</a> The Journal of Neuroscience. 29 (31), 9771-9777 (2009).</li><li>Morris, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developments+of+a+water-maze+procedure+for+studying+spatial+learning+in+the+rat.">Developments of a water-maze procedure for studying spatial learning in the rat.</a> Journal of Neuroscience Methods. 11 (1), 47-60 (1984).</li><li>Barnes, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Memory+deficits+associated+with+senescence:+A+neurophysiological+and+behavioral+study+in+the+rat.">Memory deficits associated with senescence: A neurophysiological and behavioral study in the rat.</a> Journal of Comparative and Physiological Psychology. 93 (1), 74-104 (1979).</li><li>Ormond, J., O'Keefe, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hippocampal+place+cells+have+goal-oriented+vector+fields+during+navigation.">Hippocampal place cells have goal-oriented vector fields during navigation.</a> Nature. 607 (7920), 741-746 (2022).</li><li>Wood, R. 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+honeycomb+maze+provides+a+novel+test+to+study+hippocampal-dependent+spatial+navigation.">The honeycomb maze provides a novel test to study hippocampal-dependent spatial navigation.</a> Nature. 554 (7690), 102-105 (2018).</li></ol>

S.T. is an inventor of an examined Japanese patent application publication (No. P7137179, applicant: Doshisha University) pertaining to the reconfigurable maze. F.S., K.I., H.A., and Y.T. declare no conflicts of interest.

The reconfigurable maze enabled us to conduct a variety of maze tasks in a single environment. Equally spaced holes on the floor and an interlocking system coordinated by towers with baseplates guaranteed a high degree of repeatability and reproducibility. In addition, the structure could be easily attached and detached, and the desired maze shape could be configured instantly, functioning as an efficient, flexible, and scalable system.
The reconfigurable maze allowed the animals to learn rapidly. In conventional maze experimental environments, it can be difficult to reconfigure the length and shape of the pathway, and conducting tests that combine multiple mazes is time-consuming. As demonstrated in this study, the reconfigurable maze enables maze extension in a step-by-step manner, where training post-modification of complex behavioral tests is conducted efficiently in a single day (Figure 6A,B). Furthermore, it is easy for the experimenter to make modifications. In this study, the maze assembly time was measured in multiple trials, and the experimenters consistently completed the reconstructions in about 1 to 2 min (Figure 6A).
A major advantage of this maze system is that it allows for fine-tuning the shape of the maze. Because the floor is filled with punching board holes, it is possible to perform flexible maze experiments that would be difficult to achieve with conventional maze systems. In the delayed alternation task performed in this study, the rats initiated the delay and exited the delay area by poking (Figure 5A). Placing two feeders nearby, as we have done here, is difficult in a conventional maze system with a fixed geometry. Additionally, this maze system enables counterbalanced modifications; for example, the position of Feeder B can easily be replaced on the opposite side (Figure 5A). This advantage also allows for the replication of maze configurations across laboratories. Several mazes are used for the delayed alternation task, including the figure-eight maze, the Y maze, and the W maze26,29,30. The reward zone, delay area, and delay method also differ from study to study23,31. With the reconfigurable maze, all of these different mazes can be created in a single physical environment and reproduced in different laboratories. If this system becomes widespread, it could lead to the standardization of maze tasks between laboratories.
The reconfigurable maze supports electrophysiological multiunit recordings, which examine the neural correlates that support spatial navigation22. In hippocampal formation, which is considered to play an essential role in spatial navigation, several types of cells have been reported to encode spatial information, such as cells that fire when passing a specific position32 or when approaching the boundary of the external environment33. These cell types change their firing activity based on alterations in distant landmarks16,17,18. This system is ideal for recording neural activity during spatial navigation experiments because the reconfigurable maze can change only the shape of the maze while maintaining the same environment. The reconfigurable maze maintains strict external environment control, a specification pertinent to neural activity experimentation.
The reconfigurable maze provides an optimal environment for maze experiments, with some caveats. First, the maze is constructed by fitting parts into holes in a punching board, so the angles cannot be changed flexibly. The circular maze (Figure 4E) overcomes this problem to a certain extent, but there are limitations to adding curves and angles to the pathway while ensuring the stability of the maze. In addition, some classical mazes, such as the Morris water maze34 and Barnes maze35, and mazes developed in recent years such as the honeycomb maze36,37, are difficult to construct by combining parts of the reconfigurable mazes. Future efforts should focus on exploring methodologies to merge these maze types with the reconfigurable maze to increase adaptability and cover more cognitive experimentation.

Spatial navigation is a fundamental ability of an animal to identify a suitable route to a targeted goal. Various cognitive processes, such as decision-making, learning, and memory, are needed during navigation. Utilizing these processes permits experiential learning when determining the shortest route to a goal. Maze tests are used to investigate the behavioral and physiological mechanisms of spatial navigation1. For example, the T-shaped maze2,3, plus-shaped maze4, radial arm maze5,6, and figure-eight maze7 assess spatial navigation behavior, including cognitive variables such as decision-making8 and anxiety9.
Each maze shape has advantages and disadvantages, requiring multifaceted experiments using multiple maze tasks to assess specific learning and memory10,11. For example, the spontaneous alternation task, in which an animal selects between the left and right arm without requiring learning, is a typical spatial working memory task that can be assessed with the T-shaped and Y-shaped mazes12. The plus-shaped and radial arm mazes, which use head direction and external cues, are used to determine goal-oriented navigation ability13. The figure-eight and modified T-shaped mazes, which separate the routes on selection and return, are used to evaluate spatial working memory tasks by analyzing the navigation function by trajectory14,15.
It can be challenging to maintain consistency among mazes when using several mazes in one experiment. Rodents are thought to use visual cues for navigation16,17,18; olfactory19,20 and somatosensory21 modalities may also be used for spatial cognition and may contribute to navigation ability. If a series of maze experiments are conducted using different spaces, layouts, dimensions, and materials, these variables may influence the navigation strategy of the rodents. Spatial navigation studies require the strictest control possible of these variables; however, maintaining a standardized maze apparatus for various shapes or rebuilding the maze for each experiment can be costly. These difficulties prevent a systematic way of conducting a series of experiments within the same laboratory.
To combat configured limitations in previously established maze structures, a maze system that can be configured in various shapes in a single physical environment22 is described here. The &#34;reconfigurable maze&#34; combines standardized parts, providing a highly repeatable, reproducible, flexible, and scalable testing environment. This article describes the ability of a reconfigurable maze to evaluate spatial navigation in rodents.

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utilizing a reconfigurable maze system to enhance the reproducibility of spatial navigation tests in rodents

Several maze shapes are used to test spatial navigation performance and behavioral phenotypes. Traditionally, each experiment requires a unique maze shape, thus requiring several separate mazes in different configurations. The maze geometry cannot be reconfigured in a single environment to accommodate scalability and reproducibility. The reconfigurable maze is a unique approach to address the limitations, allowing quick and flexible configurations of maze pathways in a repeatable manner. It consists of interlocking pathways and includes feeders, treadmills, movable walls, and shut-off sensors. The current protocol describes how the reconfigurable maze can replicate existing mazes, including the T-shaped, plus-shaped, W-shaped, and figure-eight mazes. Initially, the T-shaped maze was constructed inside a single experimental room, followed by modifications. The rapid and scalable protocol outlined herein demonstrates the flexibility of the reconfigurable maze, achieved through the addition of components and behavioral training phases in a stepwise manner. The reconfigurable maze systematically and precisely assesses the performance of multiple aspects of spatial navigation behavior.

Some parts of the reconfigurable maze used standard maze constructions described in previous studies3,4,7,26,27. Here, the linear track, T-shaped, W-shaped, and figure-eight mazes were reconfigured in the same physical environment (Figure 4A-D). To demonstrate that the reconfigurable maze could smoothly implement the desired behavioral test by gradual and rapid scaling, the protocol utilized for representative results included four training phases (Figure 5A).
In phases I and II, rewards were received by poking Feeder R after poking Feeder A. In phases III and IV, the reward was received by poking Feeder R after poking Feeders A and B, in that order. In phase IV, the poking of Feeder A triggered the rotation of the treadmill, and Feeder B could only be accessed after 5 s of forced running. In the test phase (delayed alternation task), the procedure was similar to that of phase IV, but Feeder R was in the arms at either edge of the T-shaped maze, and rats were rewarded by poking the opposite feeder from the previous phase. Rats were able to move in response to the length and shape of the extending pathway and changing feeder sites (Figure 5B). All phases were performed in 30 trials, with each trial defined as an instance of the rat reaching Feeder R. The task duration spent by the three rats completing 30 trials in each phase is shown in Figure 6A. Repeated measures ANOVA confirmed that the task completion time of rats differed among phases (F (4, 8) = 16.98, p &#60; 0.05, Greenhouse-Geisser corrected28). The rats were able to adapt flexibly to changes in pathway length and reward conditions. In the test phase, which was conducted the following day, all rats asymptotically approached the high percentages of correct choice responses within 3 days (Figure 6B).
Several experimenters constructed the mazes to confirm that such a stepwise maze expansion could be performed rapidly (Figure 6C). In this article, the time of the accompanying parts (treadmill, feeders) were added to the morphing time of the pathway in the previous report22 in order to measure the maze construction time practically. Using the procedure for the delayed alternation task (Figure 5A), five experimenters changed the maze from the phase II shape to the test phase shape. The time converged to 67.80 &#177; 3.03 s (mean &#177; SE) on the third trial. The test included experimenters who had used this maze system for several years and those who had rarely used it.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/64754/64754fig01.jpg" /> 
Figure 1: Elements of the reconfigurable maze. (A-E) Tower with baseplate and corresponding parts for rats. (F,G) The fixing method of the baseplate is different for rats and mice. Arrows indicate protrusions (white) and bolts (blue). (H) Signal input/output via the controller for fully automated tasks. <a href="https://www.jove.com/files/ftp_upload/64754/64754fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/64754/64754fig02.jpg" /> 
Figure 2: Connecting the punching board with the baseplate. (A) Side view of the baseplate, the punching board, and a close-up photo of a protrusion. (B) Top view of the baseplate and the punching board, and a close-up photo of the holes. <a href="https://www.jove.com/files/ftp_upload/64754/64754fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/64754/64754fig03.jpg" /> 
Figure 3: Process of T-shaped maze assembly for the delayed alternation task. (A-E) Images of the reconfigurable maze taken from above. The images of the assembly process are in order from left to right. The red arrows indicate the positions of the newly assembled treadmill (C), feeders (D), and movable walls (E). <a href="https://www.jove.com/files/ftp_upload/64754/64754fig03large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/64754/64754fig04.jpg" /> 
Figure 4: Several maze shapes in a single environment. Images of the reconfigurable maze. (A-D) Reconfigurable maze test for rats. The pathway parts were reconfigured into several shapes in a single environment, with reference to the location of the pathway parts enclosed in red in (A). (E-F) Reconfigurable maze test for mice. These mazes were placed with feeders (red arrows) and movable walls (green arrows) at any location. <a href="https://www.jove.com/files/ftp_upload/64754/64754fig04large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/64754/64754fig05.jpg" /> 
Figure 5: Maze expansion and trajectories of a rat. (A) The maze shape changes gradually during the train and test phases of the delayed alternation task. The type of feeder used in the task is indicated by a colored box. (B) Running trajectories of a representative rat. Each trajectory corresponds to the phase in (A). <a href="https://www.jove.com/files/ftp_upload/64754/64754fig05large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 6" class="xfigimg" src="/files/ftp_upload/64754/64754fig06.jpg" /> 
Figure 6: Performance of maze experiments. (A-B) The behavioral performance for 4 days, from the start of training to the end of the test. (A) Task completion time for each training phase and the first day of the test phase (n = 3). (B) The percentages of correct choice responses (mean &#177; SE) in the delayed alternation test. Dotted lines indicate chance levels. SE: standard error of the mean. (C) Reconfigurable maze assembly time. The linear track was modified into a T-shaped maze (top). The modification included the addition of pathways (white square), feeders (black square), and a treadmill (green square). Five experimenters performed three trials each (bottom). Before the test, the expert user (Experimenter 1) performed one trial as an example. All trials were performed on the same day. <a href="https://www.jove.com/files/ftp_upload/64754/64754fig06large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

Watch this Scientific Journal Video about Utilizing a Reconfigurable Maze System to Enhance the Reproducibility of Spatial Navigation Tests in Rodents at JoVE.com

Utilizing a Reconfigurable Maze System to Enhance the Reproducibility of Spatial Navigation Tests in Rodents

The present protocol describes a reconfigurable maze, a unique system for testing spatial navigation and behavioral phenotypes in rodents. The adaptability of this maze system enables the execution of various experiments in a single physical environment. The ease of structural rearrangement generates reliable and reproducible experimental results.

Several maze shapes are used to test spatial navigation performance and behavioral phenotypes. Traditionally, each experiment requires a unique maze ...

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2.4K Views.  Doshisha University. The present protocol describes a reconfigurable maze, a unique system for testing spatial navigation and behavioral phenotypes in rodents. The adaptability of this maze system enables the execution of various experiments in a single physical environment. The ease of structural rearrangement generates reliable and reproducible experimental results.

Video: Utilizing a Reconfigurable Maze System to Enhance the Reproducibility of Spatial Navigation Tests in Rodents

Shallow Water (Paddling) Variants of Water Maze Tests in Mice

When Richard Morris devised his water maze in 19817, most behavioral work was done in rats. However, the greater understanding of mouse genetics led to the mouse becoming increasingly important. But researchers found that some strains of mutant mice were prone to problems like passively floating or diving when they were tested in the Morris water maze11. This was unsurprising considering their natural habitat; rats swim naturally (classically, the "sewer rat"), whereas mice evolved in the dry areas of central Asia.
To overcome these problems, it was considered whether shallow water would be a sufficient stimulus to provide escape motivation for mice. This would also avoid the problems of drying the small creatures with a towel and then putting them in a heated recovery chamber to avoid hypothermia, which is a much more serious problem than with rats; the large ratio of surface area to volume of a mouse makes it particularly vulnerable to rapid heat loss.
Another consideration was whether a more natural escape strategy could be used, to facilitate learning. Since animals that fall into water and swim away from the safety of the shore are unlikely to pass on their genes, animals have evolved a natural tendency to swim to the edge of a body of water. The Morris water maze, however, requires them to swim to a hidden platform towards the center of the maze - exactly opposite to their evolved behavior. Therefore the paddling maze should incorporate escape to the edge of the apparatus. This feature, coupled with the use of relatively non-aversive shallow water, embodies the "Refinement" aspect of the "3 Rs" of Russell and Burch8.
Various types of maze design were tried; the common feature was that the water was always shallow (2 cm deep) and escape was via a tube piercing the transparent wall of the apparatus. Other tubes ("false exits") were also placed around the walls but these were blocked off. From the inside of the maze all false exits and the single true exit looked the same. Currently a dodecagonal (12-sided) maze is in use in Oxford, with 12 true/false exits set in the corners. In a recent development a transparent paddling Y-maze has been tested successfully.

Shallow Water Paddling Variants of Water Maze Tests in Mice

Mice can swim, but many strains appear to find this activity stressful. To overcome this problem mazes have been devised where escape from shallow water is used to motivate behaviour. These have been demonstrated to support learning at least as good as the traditional and widely used Morris water maze.

When Richard Morris devised his water maze in 19817, most behavioral work was done in rats. However, the greater understanding of mouse genetics led to ...

The Double-H Maze: A Robust Behavioral Test for Learning and Memory in Rodents

Spatial cognition research in rodents typically employs the use of maze tasks, whose attributes vary from one maze to the next. These tasks vary by their behavioral flexibility and required memory duration, the number of goals and pathways, and also the overall task complexity. A confounding feature in many of these tasks is the lack of control over the strategy employed by the rodents to reach the goal, e.g., allocentric (declarative-like) or egocentric (procedural) based strategies. The double-H maze is a novel water-escape memory task that addresses this issue, by allowing the experimenter to direct the type of strategy learned during the training period. The double-H maze is a transparent device, which consists of a central alleyway with three arms protruding on both sides, along with an escape platform submerged at the extremity of one of these arms.
Rats can be trained using an allocentric strategy by alternating the start position in the maze in an unpredictable manner (see protocol 1; &#167;4.7), thus requiring them to learn the location of the platform based on the available allothetic cues. Alternatively, an egocentric learning strategy (protocol 2; &#167;4.8) can be employed by releasing the rats from the same position during each trial, until they learn the procedural pattern required to reach the goal. This task has been proven to allow for the formation of stable memory traces.
Memory can be probed following the training period in a misleading probe trial, in which the starting position for the rats alternates. Following an egocentric learning paradigm, rats typically resort to an allocentric-based strategy, but only when their initial view on the extra-maze cues differs markedly from their original position. This task is ideally suited to explore the effects of drugs/perturbations on allocentric/egocentric memory performance, as well as the interactions between these two memory systems.

The goal of this protocol is to investigate spatial cognition in rodents. The double-H water maze is a novel test, which is particularly useful to elucidate the different components of learning, consolidation and memory, as well as the interplay of memory systems.

Spatial cognition research in rodents typically employs the use of maze tasks, whose attributes vary from one maze to the next. These tasks vary by their ...

Place and Response Learning in the Open-field Tower Maze

This protocol describes how the Open-field Tower Maze (OFTM) paradigm is used to study spatial learning in rodents. This maze is especially useful for examining how rats learn to use a place- or response-learning to successfully navigate in an open-field arena. Additionally, this protocol describes how the OFTM differs from other behavioral maze paradigms that are commonly used to study spatial learning in rodents. The OFTM described in this article was adapted from the one previously described by Cole, Clipperton, and Walt (2007). Specifically, the OFTM was created to test spatial learning in rodents without the experimenter having to consider how &#8220;stress&#8221; might play a role as a confounding variable. Experiments have shown that stress-alone can significantly affect cognitive function1. The representative results section contains data from an experiment that used the OFTM to examine the effects of estradiol treatment on place- and response-learning in adult female Sprague Dawley rats2. Future studies will be designed to examine the role of the hippocampus and striatum in place- and response-learning in the OFTM.

The Open-field Tower Maze (OFTM) is a maze created to study the behavioral and neural mechanisms of spatial learning (e.g., place- or response-learning) in rats. This maze is especially useful for experimenters who want to use a non-stressful maze paradigm to investigate spatial learning in their research.

This protocol describes how the Open-field Tower Maze (OFTM) paradigm is used to study spatial learning in rodents. This maze is especially useful for ...

Assessing Spatial Memory Impairment in a Mouse Model of Traumatic Brain Injury Using a Radial Water Tread Maze

Despite the recent increase in use of mouse models in scientific research, researchers continue to use cognitive tasks that were originally designed and validated for rat use. The Radial Water Tread (RWT) maze test of spatial memory (designed specifically for mice and requiring no swimming) has been shown previously to successfully distinguish between controlled cortical impact-induced TBI mice and sham controls. Here, a detailed protocol for this task is presented. The RWT maze capitalizes on the natural tendency of mice to avoid open areas in favor of hugging the sides of an apparatus (thigmotaxis). The walls of the maze are lined with nine escape holes placed above the floor of the apparatus, and mice are trained to use visual cues to locate the escape hole that leads out of the maze. The maze is filled with an inch of cold water, sufficient to motivate escape but not deep enough to require that the mouse swim. The acquisition period takes only four training days, with a test of memory retention on day five and a long-term memory test on day 12. The results reported here suggest that the RWT maze is a feasible alternative to rat-validated, swimming-based cognitive tests in the assessment of spatial memory deficits in mouse models of TBI.

Here we present a protocol for a mouse-specific test of cognition that does not require swimming. This test can be used to successfully distinguish controlled cortical impact-induced traumatic brain injury mice from sham controls.

Despite the recent increase in use of mouse models in scientific research, researchers continue to use cognitive tasks that were originally designed and ...

Utilizing the Modified T-Maze to Assess Functional Memory Outcomes After Cardiac Arrest

Background: Evaluating mild to moderate cognitive impairment in a global cerebral ischemia (i.e. cardiac arrest) model can be difficult due to poor locomotion after surgery. For example, rats who undergo surgical procedures and are subjected to the Morris water maze may not be able to swim, thus voiding the experiment.
New Method: We established a modified behavioral spontaneous alternation T-maze test. The major advantage of the modified T-maze protocol is its relatively simple design that is powerful enough to assess functional learning/memory after ischemia. Additionally, the data analysis is simple and straightforward. We used the T-maze to determine the rats&#39; learning/memory deficits both in the presence or absence of mild to moderate (6 min) asphyxial cardiac arrest (ACA). Rats have a natural tendency for exploration and will explore the alternate arms in the T-maze, whereas hippocampal-lesioned rats tend to adopt a side-preference resulting in decreased spontaneous alternation ratios, revealing the hippocampal-related functional learning/memory in the presence or absence of ACA.
Results: ACA groups have higher side-preference ratios and lower alternations as compared to control.
Comparison with Existing Method(s): The Morris water and Barnes maze are more prominent for assessing learning/memory function. However, the Morris water maze is more stressful than other mazes. The Barnes maze is widely used to measure reference (long-term) memory, while ACA-induced neurocognitive deficits are more closely related to working (short-term) memory.
Conclusions: We have developed a simple, yet effective strategy to delineate working (short-term) memory via the T-maze in our global cerebral ischemia model (ACA).

This protocol describes the use of a modified T-maze to evaluate functional learning/memory in asphyxia cardiac arrest-induced cerebral ischemia.

Background: Evaluating mild to moderate cognitive impairment in a global cerebral ischemia (i.e. cardiac arrest) model can be difficult due to poor ...

Analyzing Spatial Learning and Prosocial Behavior in Mice Using the Barnes Maze and Damsel-in-Distress Paradigms

The Barnes maze is a reliable measure of spatial learning and memory that does not require food restriction or exposure to extremely stressful stimuli. The Barnes maze can also assess other mouse behaviors, such as general motivation to escape from the maze platform and exploratory behavior. The Barnes maze can measure whether a genetic mutation or environmental variable can impact the acquisition and retention of spatial memories, as well as provide information about the search strategy employed by the mice. Here we use the Barnes maze to detect a memory deficit in adult mice following a single developmental ethanol exposure event. The newly described Damsel-in-Distress paradigm exposes a male mouse to a female mouse trapped in a chamber in the open center field of the arena. It provides an opportunity for the mouse to socially respond to the trapped female and exhibit prosocial behavior. The Damsel-in-Distress paradigm can also be used to examine mouse behavior in a novel arena and measure locomotor activity. Both the Barnes Maze and the Damsel-in-Distress protocols require minimal financial investment and most aspects of the tests can be constructed from common lab supplies. These flexible and accessible tools can also be used to detect behavioral changes over the course of development.

This protocol measures spatial learning and memory using the Barnes maze. A novel Damsel-in-Distress paradigm is used to assess locomotor activity and prosocial behavior in mice.

The Barnes maze is a reliable measure of spatial learning and memory that does not require food restriction or exposure to extremely stressful stimuli. ...

A System for Tracking the Dynamics of Social Preference Behavior in Small Rodents

Exploring the neurobiological mechanisms of social behavior requires behavioral tests that can be applied to animal models in an unbiased and observer-independent manner. Since the beginning of the millennium, the three-chamber test has been widely used as a standard paradigm to evaluate sociability (social preference) and social novelty preference in small rodents. However, this test suffers from multiple limitations, including its dependence on spatial navigation and negligence of behavioral dynamics. Presented and validated here is a novel experimental system that offers an alternative to the three-chamber test, while also solving some of its caveats. The system requires a simple and affordable experimental apparatus and publicly available open-source analysis system, which automatically measures and analyzes multiple behavioral parameters at individual and population levels. It allows detailed analysis of the behavioral dynamics of small rodents during any social discrimination test. We demonstrate the efficiency of the system in analyzing the dynamics of social behavior during the social preference and social novelty preference tests as performed by adult male mice and rats. Moreover, we validate the ability of the system to reveal modified dynamics of social behavior in rodents following manipulations such as whisker trimming. Thus, the system allows for rigorous investigation of social behavior and dynamics in small rodent models and supports more accurate comparisons between strains, conditions, and treatments.

Described here is a novel automated experimental system that offers an alternative to the three-chamber test and also solves several caveats. This system supplies multiple behavioral parameters that enable rigorous analysis of small rodent behavioral dynamics during the social preference and social novelty preference tests.

Exploring the neurobiological mechanisms of social behavior requires behavioral tests that can be applied to animal models in an unbiased and ...

The Use of Traditional Fear Tests to Evaluate Different Emotional Circuits in Cattle

Animal temperament is complex and has implications for productivity and economic profitability. Quantifying an animal&#39;s response to differing stimuli may facilitate breeding selections and identify animals that are better suited to specific management strategies. Multiple tests have been developed to evaluate cattle temperament (e.g., exit velocity, chute score, pen score, open field test, startle test, bovine zero maze), but each of these tests evaluates the animal&#39;s response to different stimuli (e.g., isolation, novel environment, startle, willingness to enter an enclosed area). Cattle temperament has been observed to be relatively stable over time. However, the evaluation of temperament has the potential to be influenced by current conditions, previous experiences, and observer bias. Many of these temperament tests have been improperly categorized as fear tests and have also been criticized for being subjective. This paper provides a framework for standardizing behavioral tests for cattle and suggests that these different evaluations assess different aspects of the animal&#39;s overall temperament.

Here, we present a protocol to conduct a variety of behavioral tests in cattle that have been designed to evaluate emotions. A battery of behavioral tests (open field test, startle test, bovine zero maze, exit velocity, pen score, and chute score) were conducted to evaluate different components of animal temperament.

Animal temperament is complex and has implications for productivity and economic profitability. Quantifying an animal&#39;s response to differing stimuli ...

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 ...

Operative Technique and Nuances for the Stereoelectroencephalographic (SEEG) Methodology Utilizing a Robotic Stereotactic Guidance System

The SEEG methodology has gained favor in North America over the last decade as a means of localizing the epileptogenic zone (EZ) prior to epilepsy surgery. Recently, the application of a robotic stereotactic guidance system for implantation of SEEG electrodes has become more popular in many epilepsy centers. The technique for the use of the robot requires extreme precision in the pre-surgical planning phase and then the technique is streamlined during the operative portion of the methodology, as the robot and surgeon work in concert to implant the electrodes. Herein is detailed precise operative methodology of using the robot to guide implantation of SEEG electrodes. A major limitation of the procedure, namely its heavy reliance on the ability to register the patient to a preoperative volumetric magnetic resonance image (MRI), is also discussed. Overall, this procedure has been shown to have a low morbidity rate and an extremely low mortality rate. The use of a robotic stereotactic guidance system for the implantation of SEEG electrodes is an efficient, fast, safe, and accurate alternative to conventional manual implantation strategies.

Operative Technique and Nuances for the Stereoelectroencephalographic SEEG Methodology Utilizing a Robotic Stereotactic Guidance System

The SEEG methodology is simplified and made faster with a stereotactic robot. Careful attention must be paid to the registration of the preoperative volumetric MRI to the patient prior to use of the robot in the OR. The robot streamlines the procedure, leading to decreased operative times and accurate implantations.