Post-training reversible inactivation of hippocampus reveals interference between memory systems.
A post-training reversible lesion technique was used to examine the effects of neural inactivation of the dorsal hippocampus on place and response learning. Male Long-Evans rats trained in one of two versions of a water plus-maze task received post-training intra-hippocampal infusions of the local anesthetic drug bupivacaine (0.75% solution, 0.5 microl), or saline. Post-training intra-hippocampal infusions of bupivacaine attenuated acquisition of the place task and enhanced acquisition of the response task. Delayed (2-h) post-training infusions of bupivacaine did not affect retention in either task. The findings demonstrate (1) enhanced learning after reversible hippocampal lesions that is independent of treatment influences on non-mnemonic factors, and (2) inactivation of the dorsal hippocampus during the post-training memory consolidation period is sufficient to enhance response learning.
Schroeder
Jason P
JP
Department of Psychology, Yale University, New Haven, Connecticut 06520-8025, USA.
Wingard
Jeffrey C
JC
Packard
Mark G
MG
D000704:Analysis of Variance; D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D002045:Bupivacaine / Q000494:pharmacology; D003213:Conditioning, Psychological / Q000187:drug effects / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D008845:Microinjections; D051381:Rats; D020318:Rats, Long-Evans
D000779:Anesthetics, Local; D002045:Bupivacaine