Microcircuit dynamics of map plasticity in barrel cortex

- Chronic imaging and electrophysiology offer new insight into cortical map plasticity.
- Plasticity effects are diverse within local cortical populations.
- Distinct activity redistributions result from sensory deprivation and learning.
- Diverse synaptic, intrinsic and compensatory mechanisms likely operate in parallel.

Functional reorganization of the whisker map in rodent barrel cortex has long served as a model for cortical plasticity following changes in sensory experience. Given the heterogeneity of neuronal response properties in neocortex, it has remained unclear how individual neurons in the cortical microcircuit are affected. Novel in vivo imaging and electrophysiology methods allow longitudinal recording of the same neurons' functional properties and therefore have the critical ability to resolve the direction and dynamics of change as plasticity progresses. Tracking sensory responsiveness before and after whisker trimming has uncovered diverse effects in individual neurons, suggesting that longitudinal recording will be essential for elucidating plasticity mechanisms within cortical microcircuits.