Neuronal activity and brain-derived neurotrophic factor regulate the density of inhibitory synapses in organotypic slice cultures of postnatal hippocampus.

摘要: Hippocampal interneurons inhibit pyramidal neurons through the release of neurotransmitter GABA. Given importance this inhibition for proper functioning hippocampus, development inhibitory synapses must be tightly regulated. In study, possibility that neuronal activity and neurotrophins regulate density GABAergic was investigated in organotypic slice cultures taken from postnatal day 7 rats. hippocampal slices cultured 13 d presence GABA(A) receptor antagonist bicuculline, glutamic acid decarboxylase (GAD) 65-immunoreactive terminals increased CA1 area when compared with control slices. Treatment glutamate 6,7-dinitroquinoxaline-2,3-dione decreased GAD65-immunoreactive stratum oriens CA1. These treatments had parallel effects on GABA-immunoreactive processes. Electron microscopic analysis after postembedding immunogold labeling antibodies against GABA indicated bicuculline treatment but not excitatory synapses. Application exogenous BDNF partly mimicked stimulatory effect terminals. Finally, BDNF, nerve growth factor, decrease bicuculline-treated Thus, regulates made by interneurons, could mediate part regulation. This regulation represent a feedback mechanism aimed at maintaining an appropriate level developing networks.