TY - JOUR
T1 - En route to delineating hippocampal roles in spatial learning
AU - Poulter, Steven
AU - Austen, Joseph M.
AU - Kosaki, Yutaka
AU - Dachtler, James
AU - Lever, Colin
AU - McGregor, Anthony
N1 - Funding Information:
We acknowledge funding from research grants to Anthony McGregor ( BB/F013094/1 ) and Colin Lever ( BB/M008975/1 ) from the United Kingdom Biotechnology and Biological Sciences Research Council (BBSRC) and to Anthony McGregor from the Experimental Psychology Society .
Funding Information:
We acknowledge funding from research grants to Anthony McGregor (BB/F013094/1)and Colin Lever (BB/M008975/1)from the United Kingdom Biotechnology and Biological Sciences Research Council (BBSRC)and to Anthony McGregor from the Experimental Psychology Society. We thank Andy Long, Elaine Stanton, Claire Robinson and Heather Crawford for technical support.
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/9/2
Y1 - 2019/9/2
N2 - The precise role played by the hippocampus in spatial learning tasks, such as the Morris Water Maze (MWM), is not fully understood. One theory is that the hippocampus is not required for ‘knowing where’ but rather is crucial in ‘getting there’. To explore this idea in the MWM, we manipulated ‘getting there’ variables, such as passive transport or active swimming towards the hidden platform, in rats with and without hippocampal lesions. Our results suggested that for intact rats, self-motion cues enroute to the hidden goal were a necessary component for ‘place learning’ to progress. Specifically, intact rats could not learn the hidden goal location, when passively transported to it, despite extensive training. However, when rats were either given hippocampal lesions, or placed in a light-tight box during transportation to the hidden goal, passive-placement spatial learning was facilitated. In a subsequent experiment, the ‘getting there’ component of place navigation was simplified, via the placement of two overhead landmarks, one of which served as a beacon. When ‘getting there’ was made easier in this way, hippocampal lesions did not induce deficits in ‘knowing where’ the goal was. In fact, similar to the facilitation observed in passive-placement spatial learning, hippocampal lesions improved landmark learning relative to controls. Finally, demonstrating that our lesions were sufficiently deleterious, hippocampal-lesioned rats were impaired, as predicted, in an environmental-boundary based learning task. We interpret these results in terms of competition between multiple memory systems, and the importance of self-generated motion cues in hippocampal spatial mapping.
AB - The precise role played by the hippocampus in spatial learning tasks, such as the Morris Water Maze (MWM), is not fully understood. One theory is that the hippocampus is not required for ‘knowing where’ but rather is crucial in ‘getting there’. To explore this idea in the MWM, we manipulated ‘getting there’ variables, such as passive transport or active swimming towards the hidden platform, in rats with and without hippocampal lesions. Our results suggested that for intact rats, self-motion cues enroute to the hidden goal were a necessary component for ‘place learning’ to progress. Specifically, intact rats could not learn the hidden goal location, when passively transported to it, despite extensive training. However, when rats were either given hippocampal lesions, or placed in a light-tight box during transportation to the hidden goal, passive-placement spatial learning was facilitated. In a subsequent experiment, the ‘getting there’ component of place navigation was simplified, via the placement of two overhead landmarks, one of which served as a beacon. When ‘getting there’ was made easier in this way, hippocampal lesions did not induce deficits in ‘knowing where’ the goal was. In fact, similar to the facilitation observed in passive-placement spatial learning, hippocampal lesions improved landmark learning relative to controls. Finally, demonstrating that our lesions were sufficiently deleterious, hippocampal-lesioned rats were impaired, as predicted, in an environmental-boundary based learning task. We interpret these results in terms of competition between multiple memory systems, and the importance of self-generated motion cues in hippocampal spatial mapping.
KW - Cognitive map
KW - Getting there
KW - Hippocampus
KW - Knowing where
KW - Multiple memory systems
KW - Passive learning
KW - Self-Generated motion
KW - Spatial learning
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U2 - 10.1016/j.bbr.2019.111936
DO - 10.1016/j.bbr.2019.111936
M3 - Article
C2 - 31055057
AN - SCOPUS:85065421226
VL - 369
JO - Behavioural Brain Research
JF - Behavioural Brain Research
SN - 0166-4328
M1 - 111936
ER -