Tomer Illouz1, Ravit Madar2, Eitan Okun3. 1. The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, 5290002, Israel; The Paul Feder Laboratory on Alzheimer's Disease Research, Bar-Ilan University, Ramat Gan, 5290002, Israel. Electronic address: tomerillouz@gmail.com. 2. The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, 5290002, Israel; The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, 5290002, Israel; The Paul Feder Laboratory on Alzheimer's Disease Research, Bar-Ilan University, Ramat Gan, 5290002, Israel. Electronic address: ravit.sa@gmail.com. 3. The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, 5290002, Israel; The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, 5290002, Israel; The Paul Feder Laboratory on Alzheimer's Disease Research, Bar-Ilan University, Ramat Gan, 5290002, Israel. Electronic address: eitan.okun@biu.ac.il.
Abstract
BACKGROUND: The Morris water maze (MWM) and the Barnes maze (BM) are among the most widely-used paradigms for assessing spatial learning in rodents, with specific advantages and disadvantages for each apparatus. Compared with the intense water-related stress exerted during the MWM, the BM exhibits a milder light-induced stress, while suffering from biasing animals towards non-spatial strategies such as serial search, a heuristic non-spatial search strategy. To overcome this problem, we have developed a modified Barnes maze (MBM) apparatus that recapitulates natural environments more accurately without inducing undesirable exploration strategy bias. NEW METHOD: Apparatus. A circular 122 cm-wide table with 40 randomly placed holes. One target hole is leading to an escape chamber. Task. Three target locations were examined, varying in their distance from the center. C57BL6/j male mice were given three trials per day to find the target. Following acquisition, a probe test was performed by removing the escape chamber. RESULTS: Spatial-encoding-depended reduction in latency to reach the target was observed, along with improvement in path efficiency with test progress. Mice tested with peripheral and distal targets outperformed mice tested with a central target. A robust exploration pattern was identified in the probe test. COMPARISON WITH EXISTING METHOD: The MBM mimics natural environment to a higher degree of accuracy than the BM, without eliciting bias towards non-spatial searching strategies. CONCLUSIONS: Spatial learning in the MBM is a target-location sensitive process, providing flexibility in task difficulty. Along with overcoming biases towards non-spatial strategies, the MBM represents an improvement over the well-validated BM.
BACKGROUND: The Morris water maze (MWM) and the Barnes maze (BM) are among the most widely-used paradigms for assessing spatial learning in rodents, with specific advantages and disadvantages for each apparatus. Compared with the intense water-related stress exerted during the MWM, the BM exhibits a milder light-induced stress, while suffering from biasing animals towards non-spatial strategies such as serial search, a heuristic non-spatial search strategy. To overcome this problem, we have developed a modified Barnes maze (MBM) apparatus that recapitulates natural environments more accurately without inducing undesirable exploration strategy bias. NEW METHOD: Apparatus. A circular 122 cm-wide table with 40 randomly placed holes. One target hole is leading to an escape chamber. Task. Three target locations were examined, varying in their distance from the center. C57BL6/j male mice were given three trials per day to find the target. Following acquisition, a probe test was performed by removing the escape chamber. RESULTS: Spatial-encoding-depended reduction in latency to reach the target was observed, along with improvement in path efficiency with test progress. Mice tested with peripheral and distal targets outperformed mice tested with a central target. A robust exploration pattern was identified in the probe test. COMPARISON WITH EXISTING METHOD: The MBM mimics natural environment to a higher degree of accuracy than the BM, without eliciting bias towards non-spatial searching strategies. CONCLUSIONS: Spatial learning in the MBM is a target-location sensitive process, providing flexibility in task difficulty. Along with overcoming biases towards non-spatial strategies, the MBM represents an improvement over the well-validated BM.
Authors: Elena V Kozlova; Bruno Carabelli; Anthony E Bishay; Maximillian E Denys; Devi B Chinthirla; Jasmin D Tran; Ansel Hsiao; Nicole I Zur Nieden; Margarita C Currás-Collazo Journal: Life Sci Date: 2021-10-26 Impact factor: 6.780