Characterization of a voltage-dependent anionic channel in fused synaptosomes isolated from rat hippocampi

The inside out configuration of the patch-clamp technique was used to study single-channel anionic currents from purified hippocampal synaptosomes fused into liposomes to form giant proteoliposomes. At least six different anionic channels with unitary conductances of 22-150 pS were found. The most frequently observed was the 32-pS conductance channel. This was voltage-dependent; the open probability increased from 0.20 at -40 mV to 0.46 at 40 mV. This channel may be involved in the repolarization of nerve terminal membranes after an action potential, thus, limiting the duration of the spike and the transmitter release.