Effect of GABAB-receptor agonist and antagonist on whole-cell patch-clamp recorded rat PO/AH neurons
Department of Pharmacology, Faculty of Medicine, Medical University, 1431 Sofia, (BULGARIA)
Intracellular recordings were made from neurons in slices of the preoptic area/anterior hypothalamus (PO/AH) of rats, using whole-cell patchclamp recording techniques to investigate the effects of the GABAB-receptor agonist baclofen and GABAB-receptor antagonist CGP 35348 on neuronal response characteristics. Baclofen decreased firing rate of the neurons, regardless of their type of temperature sensitivity. The decrease in firing rate during baclofen application was accompanied with significant membrane hyperpolarization and decrease of input resistances. The firing rate (in all type of PO/AH neurons) was increased by GABAB-receptor antagonist CGP 35348 and this was accompanied with membrane depolarization and increase of input resistances. These findings were abolished when baclofen and CGP 35348 were applied simultaneously. Our results are step of understanding the complicated mechanisms of action of GABAergic agents on the level of central temperature controller – the neurons of the PO/AH.