The effects of running and of inhibiting adult neurogenesis on learning and memory in rats.
The presence of ongoing adult neurogenesis within the highly plastic hippocampal circuitry poses questions as to the relevance of new neurons to learning and memory. Correlational and causal evidence suggests that some, but not all, hippocampal tasks involve the new neurons. The evidence with regard to spatial learning in the water maze, one of the most commonly used hippocampal tasks, is contradictory. In this study we examined the effects of irradiation-induced reduction in neurogenesis on spatial learning and another standard hippocampal task, contextual fear conditioning, in rats that experienced normal cage conditions or voluntary running. The results indicate that reduced neurogenesis had little effect on spatial learning but severely impaired contextual fear conditioning. It was suggested that compensatory mechanisms within the hippocampus may have contributed selectively to sparing of spatial function. Performance on the fear conditioning task was weakly related to enhanced neurogenesis or running. The results improve our understanding of the functional role of adult neurogenesis in behaving animals.
Wojtowicz
J Martin
JM
Department of Physiology, University of Toronto, Toronto, ON, M5S 1A8, Canada. martin.wojtowicz@utoronto.ca
Askew
Michele L
ML
Winocur
Gordon
G
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology* / Q000528:radiation effects; D003037:Cobalt Radioisotopes; D005239:Fear / Q000502:physiology / Q000528:radiation effects; D006624:Hippocampus / Q000166:cytology / Q000502:physiology / Q000528:radiation effects; D007858:Learning / Q000502:physiology* / Q000528:radiation effects; D008297:Male; D008568:Memory / Q000502:physiology / Q000528:radiation effects; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011897:Random Allocation; D051381:Rats; D020318:Rats, Long-Evans
D003037:Cobalt Radioisotopes