Modulatory effects of gonadorelin on GABA-induced depolarization and GABA-activated current in rat spinal ganglion neurons.

AIM: To explore the modulatory effects of gonadorelin on GABA-induced depolarization and GABA-activated current in membrane of rat primary sensory neurons.

METHODS

Intracellular recordings and whole-cell patch clamp techniques were performed on neurons in rat spinal ganglia (SG) preparation and neurons freshly isolated from rat SG, respectively. Drugs were applied by superfusion and/or by bath application.

RESULTS

In the majority of neurons GABA (10 mumol.L-1 -1 mmol.L-1) induced a depolarization, which was blocked by bicucullin (100 mumol.L-1). Pretreatment with gonadorelin (50 mumol.L-1) decreased the GABA-induced depolarization by 79 +/- 22% (n = 29), while gonadorelin elicited no effect or slight depolarization alone. In 6 of 11 cells, GABA-activated currents were also inhibited by pretreatment with gonadorelin (50 mumol.L-1), while in 5 of 11 cells, there was no change or a slight potentiation.

CONCLUSION

Gonadorelin exerts an inhibitory effect on GABA-induced depolarization and GABA-activated current in the primary sensory neurons.