The authors would like to thank Christopher Newport University for funding the preparation of this manuscript and The University of Vermont for funding the experiments described in the representative results section.

This protocol is approved by the Institutional Animal Care and Use Committee of Christopher Newport University.
1. Construction of the OFTM Apparatus
<ol>
	<li>Construct the boundary wall (40 cm high and 183 cm diameter) from three pieces of white laminate. Construct the circular maze floor (183 cm diameter) from black laminate and glue it to a plastic table top. Secure the boundary wall to the edge of the table with screws and glue.</li>
	<li>Decorate the interior surface of the boundary wall: Leave one quarter...

<ol>
	<li>Luine, V., 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=Repeated+stress+causes+reversible+impairments+of+spatial+memory+performance.">Repeated stress causes reversible impairments of spatial memory performance.</a> Brain Res. 639 (1), 167-170 (1994).</li><li>Lipatova, O., 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+continuous+vs.+cycling+estrogen+replacement+on+the+acquisition,+retention+and+expression+of+place-+and+response-learning+in+the+open-field+tower+maze.">Effects of continuous vs. cycling estrogen replacement on the acquisition, retention and expression of place- and response-learning in the open-field tower maze.</a> Neurobiol Learn Mem. 114, 81-89 (2014).</li><li>Packard, M. G., McGaugh, 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=Double+dissociation+of+fornix+and+caudate+nucleus+lesions+on+acquisition+of+two+water+maze+tasks:+further+evidence+for+multiple+memory+systems.">Double dissociation of fornix and caudate nucleus lesions on acquisition of two water maze tasks: further evidence for multiple memory systems.</a> Behav Neurosci. 106 (3), 439-446 (1992).</li><li>Packard, M. G., McGaugh, 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=Inactivation+of+hippocampus+or+caudate+nucleus+with+lidocaine+differentially+affects+expression+of+place+and+response+learning.">Inactivation of hippocampus or caudate nucleus with lidocaine differentially affects expression of place and response learning.</a> Neurobiol Learn Mem. 65 (1), 65-72 (1996).</li><li>Poldrack, R. A., Packard, M. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Competition+among+multiple+memory+systems:+converging+evidence+from+animal+and+human+brain+studies.">Competition among multiple memory systems: converging evidence from animal and human brain studies.</a> Neuropsychologia. 41 (3), 245-251 (2003).</li><li>Quinlan, M. G., Hussain, D., Brake, W. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+cognitive+strategies+in+rats:+the+role+of+estradiol+and+its+interaction+with+dopamine.">Use of cognitive strategies in rats: the role of estradiol and its interaction with dopamine.</a> Horm Behav. 53 (1), 185-191 (2008).</li><li>Korol, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+estrogen+in+balancing+contributions+from+multiple+memory+systems.">Role of estrogen in balancing contributions from multiple memory systems.</a> Neurobiol Learn Mem. 82, 309-323 (2004).</li><li>Cole, M. R., Clipperton, A., Walt, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Place+versus+response+learning+in+rats.">Place versus response learning in rats.</a> Learn Behav. 35 (4), 214-224 (2007).</li><li>Prut, L., Belzung, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+open+field+as+a+paradigm+to+measure+the+effects+of+drugs+on+anxiety-like+behaviors:+a+review.">The open field as a paradigm to measure the effects of drugs on anxiety-like behaviors: a review.</a> Eur J Pharmaco. 463 (1-3), 3-33 (2003).</li><li>Harrison, F. E., Hosseini, A. H., McDonald, M. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endogenous+anxiety+and+stress+responses+in+water+maze+and+Barnes+maze+spatial+memory+tasks.">Endogenous anxiety and stress responses in water maze and Barnes maze spatial memory tasks.</a> Behav Brain Res. 198 (1), 247-251 (2009).</li><li>Bowman, R. E., Beck, K. D., Luine, V. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chronic+stress+effects+on+memory:+sex+differences+in+performance+and+monoaminergic+activity.">Chronic stress effects on memory: sex differences in performance and monoaminergic activity.</a> Horm Behav. 43 (1), 48-59 (2003).</li><li>Lunga, P., Herbert, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=17Beta-oestradiol+modulates+glucocorticoid,+neural+and+behavioural+adaptations+to+repeated+restraint+stress+in+female+rats.">17Beta-oestradiol modulates glucocorticoid, neural and behavioural adaptations to repeated restraint stress in female rats.</a> J Neuroendocrinol. 16 (9), 776-7785 (2004).</li><li>Newhouse, P. 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=Estrogen+treatment+impairs+cognitive+performance+after+psychosocial+stress+and+monoamine+depletion+in+postmenopausal+women.">Estrogen treatment impairs cognitive performance after psychosocial stress and monoamine depletion in postmenopausal women.</a> Menopause. 17 (4), 860-873 (2010).</li><li>Lipatova, O., Toufexis, 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=Estrogen+enhances+the+retention+of+spatial+reference+memory+in+the+open+field+tower+task,+but+disrupts+the+expression+of+spatial+memory+following+a+novel+start+position.">Estrogen enhances the retention of spatial reference memory in the open field tower task, but disrupts the expression of spatial memory following a novel start position.</a> Neurobiol Learn Mem. 99, 50-58 (2012).</li><li>Lipatova, O., 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=Recency-to-primacy+shift+in+cue+competition.">Recency-to-primacy shift in cue competition.</a> J Exp Psychol Anim Behav Process. 32 (4), 396-406 (2006).</li><li>De La Casa, L. G., Timberlake, W. <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+preexposure+and+retention+interval+placement+on+latent+inhibition+and+perceptual+learning+in+a+choice-maze+discrimination+task.">Effects of preexposure and retention interval placement on latent inhibition and perceptual learning in a choice-maze discrimination task.</a> Learn Behav. 34 (2), 193-201 (2006).</li><li>Liang, K. 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=Buspirone+impaired+acquisition+and+retention+in+avoidance+tasks:+involvement+of+the+hippocampus.">Buspirone impaired acquisition and retention in avoidance tasks: involvement of the hippocampus.</a> Chin J Physiol. 41 (1), 33-44 (1998).</li><li>Gisquet-Verrier, P., Alexinsky, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Does+contextual+change+determine+long-term+forgetting.">Does contextual change determine long-term forgetting.</a> Animal Learning and Behavior. 14 (4), 349-358 (1986).</li><li>Gisquet-Verrier, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exposure+to+retrieval+cues+improves+retention+performance+and+induces+changes+in+ACTH+and+corticosterone+release.">Exposure to retrieval cues improves retention performance and induces changes in ACTH and corticosterone release.</a> Psychoneuroendocrinology. 29 (4), 529-556 (2004).</li><li>Packard, M. G., Hirsh, R., White, N. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+effects+of+fornix+and+caudate+nucleus+lesions+on+two+radial+maze+tasks:+evidence+for+multiple+memory+systems.">Differential effects of fornix and caudate nucleus lesions on two radial maze tasks: evidence for multiple memory systems.</a> J Neurosci. 9 (5), 1465-1472 (1989).</li><li>Devan, B. D., McDonald, R. J., White, N. M. <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+medial+and+lateral+caudate-putamen+lesions+on+place-+and+cue-guided+behaviors+in+the+water+maze:+relation+to+thigmotaxis.">Effects of medial and lateral caudate-putamen lesions on place- and cue-guided behaviors in the water maze: relation to thigmotaxis.</a> Behav Brain Res. 100 (1-2), 5-14 (1999).</li></ol>

Numerous paradigms can be used to investigate learning and memory in rodents, and each has important steps that experimenters should follow. In the OFTM, it is important that maze conditions (e.g., position of maze, intra- and extra-maze cues, dim lighting and background noise level, daily time of training) are kept constant throughout the duration of the experiment. It is also necessary to minimize stress in rat subjects to ensure continuous performance in the OFTM. Stress can be kept to a minimum in female rat...

The open-field tower maze (OFTM) can be used to examine the behavioral and neurobiological mechanisms of spatial learning in rodents. Importantly, the OFTM allows researchers to study both &#8220;place-based&#8221; and &#8220;response-based&#8221; learning types. During place-learning an animal navigates through a maze using the spatial cues in the surrounding environment (e.g., a food reward is located next to a tall beacon). During response-learning the animal makes a specific turn response regardless of its position relative to spatial cues (e.g., make a left or right turn to find a food reward). It has been previously reported that response-learning and place-learning rely on two different memory systems3, 4 and mapping their neural mechanisms has been an ongoing scientific pursuit2, 5-7. The design of the OFTM was adapted from the one previously described8.
Open field paradigms (a component of the OFTM) are commonly used to investigate anxiety in rodents9. During the typical open field anxiety test rats that spend more time in the center of an open field have lower stress and anxiety levels than rats that spend more time near the perimeter. In the OFTM, a rat must enter the center of the maze to find the food reward. Therefore, correct navigation in the OFTM indicates that these rats are non-stressed. One reason why the rats are non-stressed during the training is because unlike standard open-field tests of anxiety training the OFTM requires pre-training phase during which the rat is pre-exposed to the maze over a long period of time. In addition, the training occurs in a dimly lit environment further reducing the anxiety-inducing aspect of an open field which is typically brightly lit.
Another unique feature of the OFTM, compared to some other mazes, is how learning is measured. Experimenters using the Morris Water Maze or Barnes Maze typically measure learning by analyzing the speed and/or path length a rat travels to reach its target location. These dependent measures can be affected by non-learning factors, such as changes in a rat&#8217;s general motor activity. However, the OFTM measures learning using the percent of first-choice correct response a rat makes to find the food reward. This dependent measure is not vulnerable to changes in motor performance and therefore, more accurately assesses learning than measurements of speed and distance. Nevertheless, the experimenter can also measure a rat&#8217;s speed and distance traveled in the OFTM using video tracking software.
Other maze-types, such as the T-maze, Morris Water Maze and Barnes Maze can be used to study place- and response-learning. However, the OFTM is unique in a few notable ways. First, the OFTM is a more sensitive behavioral assay than the T-maze because the OFTM has a chance performance of 25%, whereas the T-maze has a chance performance of 50%. Second, a rat can only turn in one of two ways in the T-maze, but has unrestricted route possibilities when navigating in the OFTM. Third, unlike the Morris Water Maze and Barnes Maze tasks (which have unrestricted route possibilities like the OFTM), experiments using the OFTM do not require rats to navigate through an aversive situation. Rats are motived to navigate in the Morris Water Maze to escape swimming in water and they are motivated to navigate in the Barnes Maze to avoid being in an open, brightly-lit environment. It has been demonstrated that exposure to the Morris Water Maze or Barnes Maze induces the release of stress hormone (i.e., corticosterone) in rodents10. However, rats navigate in the OFTM because they are motivated to find a food reward and training is conducted with dim ambient lighting. Thus, the OFTM is a non-aversive appetitive task. Results from experiments that use a stressful maze paradigm to examine the effects of manipulations such as drug, hormone, exercise, or diet on learning and memory mechanisms can be difficult to interpret because &#8220;stress&#8221;, by itself, may influence cognitive function11.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>OFTM construction supplies</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Safety Glasses, Clear, Uncoated</td>
			<td>Grainger</td>
			<td>4EY97</td>
			<td>Used for general eye protection during maze construction</td>
		</tr>
		<tr>
			<td>Masking Tape, Beige, 18mm x 55m</td>
			<td>Grainger</td>
			<td>15F739</td>
			<td>General supply</td>
		</tr>
		<tr>
			<td>Wiss All-purpose Scissor</td>
			<td>Home Depot&#160;</td>
			<td>37103278647</td>
			<td>General supply</td>
		</tr>
		<tr>
			<td>Lancaster&#160; 6 foot Round Folding table - Heavy Duty white granite plastic - 29&#34;&#160;</td>
			<td>www.webstaurantstore.com</td>
			<td>384YCZ72RND</td>
			<td>Used as base of the maze</td>
		</tr>
		<tr>
			<td>Laminate Countertop sheet in White Matte Finish (48 x 96 x 0.039)</td>
			<td>Home Depot&#160;</td>
			<td>1573603504896</td>
			<td>Used as walls for the maze</td>
		</tr>
		<tr>
			<td>Laminate Countertop sheet in Black Matte Finish (48 x 96 x 0.039)</td>
			<td>Home Depot&#160;</td>
			<td>1595603504896</td>
			<td>Used as floor of the maze</td>
		</tr>
		<tr>
			<td>Adhesive, Spray, 24oz, 17.6oz Net. 3M</td>
			<td>Grainger</td>
			<td>3MA16</td>
			<td>Used to adhere the laminate floor to the table top and pieces of laminate to each other</td>
		</tr>
		<tr>
			<td>16.6 oz #90 hi-strength S</td>
			<td>Lowe&#39;s</td>
			<td>193252</td>
			<td>Used to adhere the laminate floor to the table top</td>
		</tr>
		<tr>
			<td>Superflex RTV, Silicone Adhesive Sealant, Loctile</td>
			<td>VWR</td>
			<td>300040-068</td>
			<td>Used to seal around the baze (between the floor and walls of the maze)</td>
		</tr>
		<tr>
			<td>Industrial Sealant; 10.1oz</td>
			<td>Grainger</td>
			<td>4UH06</td>
			<td>Used to seal around the baze (between the floor and walls of the maze)</td>
		</tr>
		<tr>
			<td>Painter&#39;s Masking Tape; Shurtape; 2in x 60yd</td>
			<td>Grainger</td>
			<td>6FET7</td>
			<td>Used to mark out visual patterns on maze walls</td>
		</tr>
		<tr>
			<td>Mini/Trim paint tray</td>
			<td>ACE Hardware</td>
			<td>1365105</td>
			<td>Used to hold paint&#160;</td>
		</tr>
		<tr>
			<td>Foam mini roller 4&#34; 6pk</td>
			<td>ACE Hardware</td>
			<td>1494871</td>
			<td>Used for painting patterns&#160;</td>
		</tr>
		<tr>
			<td>Val Sample Set Nbase paint</td>
			<td>ACE Hardware</td>
			<td>1505031</td>
			<td>Used as paint for pattern on the walls of the maze</td>
		</tr>
		<tr>
			<td>HP Paint Black</td>
			<td>Walmart</td>
			<td>72450405005</td>
			<td>Used to paint pattern on the walls of the maze</td>
		</tr>
		<tr>
			<td>Brush</td>
			<td>Walmart</td>
			<td>81773801110</td>
			<td>Used to paint pattern on the walls of the maze</td>
		</tr>
		<tr>
			<td>Duct Tape, 2in X 60yd, 10.5mil. Black</td>
			<td>Grainger</td>
			<td>15F767</td>
			<td>Used to wrap the exterior of the maze</td>
		</tr>
		<tr>
			<td>4X4 8ft PT pine Vinyl-CTD Post W/Cap</td>
			<td>Home Depot&#160;</td>
			<td>40933070541</td>
			<td>Used to build towers for the maze</td>
		</tr>
		<tr>
			<td>20 gram Pro Super Glue</td>
			<td>Lowe&#39;s</td>
			<td>125870</td>
			<td>Used to glue tower tops, towers to the floor of the maze and food cups to the tower tops</td>
		</tr>
		<tr>
			<td>Bead Containers 9 - 1/2</td>
			<td>Michaels</td>
			<td>652695766978</td>
			<td>Used as food cups on top of towers</td>
		</tr>
		<tr>
			<td>Spray Paint, Black, 12oz</td>
			<td>Grainger</td>
			<td>6KP22</td>
			<td>Used to paint food cups &#38; covers</td>
		</tr>
		<tr>
			<td>Room prepration</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Conair SU1W Sound Machine; 10 Sounds</td>
			<td>Home Depot&#160;</td>
			<td>204493600</td>
			<td>Used for background noise</td>
		</tr>
		<tr>
			<td>Lamp</td>
			<td>Walmart</td>
			<td>5027698392</td>
			<td>Used for dim lighting of maze room</td>
		</tr>
		<tr>
			<td>ES 14W DayLight Spiral Bulb 4pk</td>
			<td>Home Depot&#160;</td>
			<td>762148208433</td>
			<td>Used for dim lighting of maze room</td>
		</tr>
		<tr>
			<td>Shower Curtain</td>
			<td>Walmart</td>
			<td>3429910901</td>
			<td>Used for separation between the maze and the experimenter</td>
		</tr>
		<tr>
			<td>Curtain Rod</td>
			<td>Bed Bath &#38; Beyond</td>
			<td>76598645104</td>
			<td>Used for separation between the maze and the experimenter</td>
		</tr>
		<tr>
			<td>Froot Loops Cereal</td>
			<td>Walmart</td>
			<td>3800039122</td>
			<td>Used as reward</td>
		</tr>
		<tr>
			<td>Recording equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Media Recorder 3: 4 video</td>
			<td>Noldus</td>
			<td>NMR4-0200</td>
			<td>Used to record training trials</td>
		</tr>
		<tr>
			<td>Monochrome GigE Camera</td>
			<td>Noldus</td>
			<td>XCFW-BG62</td>
			<td>Used to record training trials</td>
		</tr>
		<tr>
			<td>Precision M4800 Laptop</td>
			<td>Dell</td>
			<td>N/A</td>
			<td>Used to run video software</td>
		</tr>
	</tbody>
</table>

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 representative results described here have been previously published in the Neurobiology of Learning &#38; Memory, Elsevier2. In this experiment the OFTM was used to test the effects of chronic and cycling estradiol treatments on place- and response-learning in female Sprague-Dawley rats (250 &#8211; 300 g; N = 48). There were two important reasons why the OFTM was used to conduct this experiment. First, estradiol has been shown to induce differential effects on place- and response-learning7. Se...

Watch this Scientific Journal Video about Place and Response Learning in the Open-field Tower Maze at JoVE.com

Place and Response Learning in the Open-field Tower Maze

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 ...

place-and-response-learning-in-the-open-field-tower-maze

Research

JoVE Journal

Behavior

10.1K Views.  Christopher Newport University.  L'Open-campo di Torre Maze (OFTM) è un labirinto creato per studiare i meccanismi comportamentali e neurali di apprendimento spaziale (ad esempio, o la risposta luogo--learning) nei ratti. Questo labirinto è particolarmente utile per sperimentatori che desiderano utilizzare un paradigma labirinto non stressante per studiare l'apprendimento spaziale nella loro ricerca. 