Maturation of a recurrent excitatory neocortical circuit by experience-dependent unsilencing of newly formed dendritic spines.

ABSTRACT: Local recurrent excitatory circuits are ubiquitous in neocortex, yet little is known about their development or architecture. Here we introduce a quantitative technique for efficient single-cell resolution circuit mapping using 2-photon (2P) glutamate uncaging and analyze experience-dependent neonatal development of the layer 4 barrel cortex local excitatory circuit. We show that sensory experience specifically drives a 3-fold increase in connectivity at postnatal day (P) 9, producing a highly recurrent network. A profound dendritic spinogenesis occurs concurrent with the connectivity increase, but this is not experience dependent. However, in experience-deprived cortex, a much greater proportion of spines lack postsynaptic AMPA receptors (AMPARs) and synaptic connectivity via NMDA recepto

SUBMITTER: Ashby MC 

PROVIDER: S-EPMC3092126 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature