Hippocampal lesions impair contextual fear conditioning in two strains of mice.
Two different strains of mice, C57BL/6J and BALB/c, with hippocampal, cortical, or sham lesions, underwent contextual fear conditioning. In both strains, contextual fear, as measured by the freezing response, was significantly impaired in hippocampus-lesioned animals compared with sham control animals. Fear conditioning was not affected in the cortical-lesioned group. Moreover, there was a strain difference in fear conditioning: The C57BL/6J mice exhibited freezing more frequently than the BALB/c mice. Consistent with previous hippocampal lesion studies in rats, these results indicate that contextual fear conditioning in mice also requires the intact hippocampus. This study provides a basis for evaluating hippocampal synaptic mechanisms in relation to contextual fear conditioning in widely available gene knockout or transgenic mice.
Chen
C
C
Howard Hughes Medical Institute, Center for Learning and Memory, Massachusetts Institute of Technology, Cambridge 02139, USA. cchen@wccf.mit.edu.
Kim
J J
JJ
Thompson
R F
RF
Tonegawa
S
S
D000818:Animals; D001245:Association Learning / Q000502:physiology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology; D003214:Conditioning, Classical / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D005260:Female; D006624:Hippocampus / Q000502:physiology*; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000502:physiology; D012931:Social Environment; D013045:Species Specificity; D009435:Synaptic Transmission / Q000502:physiology