Robust tonic GABA currents can inhibit cell firing in mouse newborn neocortical pyramidal cells.

ABSTRACT: Within the hippocampus and neocortex, GABA is considered to be excitatory in early development due to a relatively depolarized Cl(-) reversal potential (E(Cl)). Although the depolarizing nature of synaptic GABAergic events has been well established, it is unknown whether cortical tonic currents mediated by extrasynaptically located GABA(A) receptors (GABA(A) Rs) are also excitatory. Here we examined the development of tonic currents in the neocortex and their effect on neuronal excitability. Mean tonic current, recorded from layer 5 (L5) pyramidal cells of the mouse somatosensory cortex, is robust in newborns [postnatal day (P)2-4] then decreases dramatically by the second postnatal week (P7-10 and P30-40). Pharmacological studies, in combination with Western blot analysis, show that neona

SUBMITTER: Sebe JY 

PROVIDER: S-EPMC2956765 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature