Intracellular Na+ inhibits voltage-dependent N-type Ca2+ channels by a G protein betagamma subunit-dependent mechanism.

N-type voltage-dependent Ca(2+) channels (N-VDCCs) play important roles in neurotransmitter release and certain postsynaptic phenomena. These channels are modulated by a number of intracellular factors, notably by Gbetagamma subunits of G proteins, which inhibit N-VDCCs in a voltage-dependent (VD) manner. Here we show that an increase in intracellular Na(+) concentration inhibits N-VDCCs in hippocampal pyramidal neurones and in Xenopus oocytes.