Bittner, K. C., Milstein, A. D., Grienberger, C., Romani, S., & Magee, J. C. (2017). Behavioral time scale synaptic plasticity underlies CA1 place fields. Science, 357(6355), 1033-1036. https://www.science.org/doi/full/10.1126/science.aan3846
Intracellular recordings in CA1 of head-fixed mice running on a treadmill as well as slice electrophysiology
Mouse hippocampus
Bittner et al. recorded from individual CA1 pyramidal neurons in head-fixed mice running along a linear-track treadmill. Initially the CA1 cell was unresponsive but, following a plateau potential initiation (either spontaneously generated or induced by current injection) the CA1 cell now showed a lasting place field response to this location on the track. The authors provide evidence that all of the synapses that had been active within a several second time window centered on the plateau potential are potentiated. Evidence included slice experiments in which the precise timing characteristics of this Behavioral Time Scale Plasticity (BTSP) were measured as well as its sensitivity to calcium dynamics. BTSP’s characteristics are distinct from Hebbian plasticity in that potentiated inputs do not have to be causally related to the post-synaptic cell’s firing, do not have to be coincident on the millisecond time scale, and do not require repeated pairings. In contrast, BTSP seems well tailored to the task of one-shot learning of a place field.
“We discovered that place fields in hippocampal area CA1 are produced by a synaptic potentiation notably different from Hebbian plasticity. Place fields could be produced in vivo in a single trial by potentiation of input that arrived seconds before and after complex spiking… This plasticity efficiently stores entire behavioral sequences within synaptic weights to produce predictive place cell activity.”
