NITRIC-OXIDE SENSITIVE DEPOLARIZATION-INDUCED HYPERPOLARIZATION - A POSSIBLE ROLE FOR GAP-JUNCTIONS DURING DEVELOPMENT

Electrical coupling is a widespread feature of developing neuronal cir cuits and it contributes to the generation of patterned activity, In t he developing rat hippocampus, release of GABA by coactive hilar inter neurones generates widespread synchronized activity, Here it is shown that hilar interneurones strongly rectify in the outward direction whe n depolarized, This depolarization-induced hyperpolarization, abolishe d by gap junction uncouplers, is modulated by nitric oxide, This pheno menon might represent a current-shunting mechanism of the excess curre nt by providing functional inhibition at a developmental stage when GA BA is excitatory, Spatial buffering of the current might represent an osmotic mechanism for growth and differentiation.