Experience-dependent, asymmetric expansion of hippocampal place fields.
Theories of sequence learning based on temporally asymmetric, Hebbian long-term potentiation predict that during route learning the spatial firing distributions of hippocampal neurons should enlarge in a direction opposite to the animal's movement. On a route AB, increased synaptic drive from cells representing A would cause cells representing B to fire earlier and more robustly. These effects appeared within a few laps in rats running on closed tracks. This provides indirect evidence for Hebbian synaptic plasticity and a functional explanation for why place cells become directionally selective during route following, namely, to preserve the synaptic asymmetry necessary to encode the sequence direction.
Mehta
M R
MR
ARL Division of Neural Systems, Memory and Aging, Department of Psychology, University of Arizona, Tucson, AZ 85724, USA.
Barnes
C A
CA
McNaughton
B L
BL
D000818:Animals; D007839:Functional Laterality / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology*; D007858:Learning / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology; D009473:Neuronal Plasticity; D051381:Rats; D011916:Rats, Inbred F344