Ming Chang, Hiroshi Saito and Kazuho Abe (*)
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
(*) To whom correspondence should be addressed.
Abstract: We investigated the effects of histamine H3-receptor ligands on hippocampal synaptic transmission by using anesthetized rats in vivo. The medial perforant path was stimulated, and the population excitatory postsynaptic potential (pEPSP) and population spike were recorded from the granule cell layer of the dentate gyrus. Intracerebroventricular injection of the H3-receptor agonist (R)-alpha-methylhistamine decreased both the pEPSP and population spike, while H3-receptor antagonists, clobenpropit and thioperamide, increased both the pEPSP and population spike. These results suggest that the histaminergic system plays a role in inhibition of hippocampal synaptic excitation via the H3 receptor.
Keywords: Histamine H3 receptor, Excitatory synaptic transmission, Dentate gyrus