Zn2+ depresses GABAA receptor mediated responses in acutely dissociated sacral dorsal commissural neurons

The effects of Zn2+ on GABAA-receptor mediated responses in acutely isolated rat sacral dorsal commissural nucleus (SDCN) were studied using nystatin-perforated whole cell recording techniques. The results demonstrated that (1) GABA induced inward currents through activation of GABAA-receptor at a holding potential of -40 mV; (2) GABAA-receptor mediated responses were suppressed by Zn2+ in a reversible and voltage-independent manner; and (3) in the presence of Zn2+, the concentration-response curve of GABA-induced responses was shifted to the right in a parallel manner. The results suggest that Zn2+ allosterically depresses GABAA-receptor mediated currents.