Abstract
GABAA receptor-mediated responses are often depolarizing in immature neurons, which was mainly due to a high [Cl−]i. Therefore Cl− transporters that change [Cl−]i may affect synaptic responses and synaptic development of immature neurons. To investigate the roles of Cl− transporters in synaptic development, we cultured rat neocortical neurons for 2 weeks in the presence of NKCC (Na+-K+-Cl− cotransporter) inhibitor bumetanide and examined the sEPSCs and sIPSCs.Chronic treatment with 10 μM bumetanide during cultivation decreased the soma size of neurons. The frequency of sIPSC but not of sEPSC decreased after chronic treatment with bumetanide. These results suggest that cation-chloride cotransporters such as NKCC affect synaptic activities and synaptic development presumably by attenuating depolarized GABA responses. [Jpn J Physiol 55 Suppl:S144 (2005)]
