Synaptic plasticity in the hippocampus of awake C57BL/6 and DBA/2 mice: interstrain differences and parallels with behavior.
C57BL/6 mice consistently outperform DBA/2 mice in a range of hippocampal-dependent spatial learning behaviors. We recorded evoked responses from the dentate gyrus of awake, freely-moving mice and measured synaptic plasticity (LTP) and performance in a hippocampal-dependent task in individual animals from these two inbred strains. Spatial alternation tasks confirmed the behavioral divergence between the two strains, with C57BL/6 mice demonstrating more robust alternation than DBA/2 mice. Recording changes in field potentials in the dentate gyrus following three different high-frequency stimulation paradigms in the same groups of animals revealed differences in neural plasticity: both strains were able to support long-term potentiation (LTP) at perforant path synapses, but brief high-frequency stimulation induced larger and longer potentiation of the population spike in C57BL/6 than in DBA/2 mice. This greater propensity for population-spike potentiation in the strain that performed better in a hippocampal-dependent task is in accord with the different neurochemical profiles of C57BL/6 and DBA/2 mice.
Jones
M W
MW
Division of Neurophysiology, National Institute for Medical Research, London, UK. mwjones@mit.edu
Peckham
H M
HM
Errington
M L
ML
Bliss
T V
TV
Routtenberg
A
A
D000200:Action Potentials; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D004558:Electric Stimulation / Q000379:methods; D006624:Hippocampus / Q000502:physiology*; D008297:Male; D018782:Maze Learning / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL / Q000502:physiology*; D008811:Mice, Inbred DBA / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D013045:Species Specificity; D013569:Synapses / Q000502:physiology*