Experience-dependent asymmetric shape of hippocampal receptive fields.
We propose a novel parameter, namely, the skewness, or asymmetry, of the shape of a receptive field to characterize two properties of hippocampal place fields. First, a majority of hippocampal receptive fields on linear tracks are negatively skewed, such that during a single pass the firing rate is low as the rat enters the field but high as it exits. Second, while the place fields are symmetric at the beginning of a session, they become highly asymmetric with experience. Further experiments suggest that these results are likely to arise due to synaptic plasticity during behavior. Using a purely feed forward neural network model, we show that following repeated directional activation, NMDA-dependent long-term potentiation/long-term depotentiation (LTP/LTD) could result in an experience-dependent asymmetrization of receptive fields.
Mehta
M R
MR
Center for Learning and Memory, RIKEN-MIT Neuroscience Research Center, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge 02139, USA. mayank@mit.edu
Quirk
M C
MC
Wilson
M A
MA
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D003213:Conditioning, Psychological / Q000502:physiology*; D004594:Electrophysiology; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology; D009949:Orientation / Q000502:physiology; D017966:Pyramidal Cells / Q000502:physiology; D051381:Rats; D020318:Rats, Long-Evans; D013028:Space Perception / Q000502:physiology*