DIBENZOAZEPINE ANALOGS - THE ELECTROPHYSIOLOGICAL PROPERTIES OF JL3, A POTENTIAL ATYPICAL ANTIDEPRESSANT

JL3, lpiperazin-1-yl)pyrido[4,3-b][1,4]benzothiazepine, has potent ant idepressant-like activity in Porsolt's test in mice. Therefore, its in fluence on the electrical activity of central monoaminergic neurons wa s investigated in rats anaesthetized with chloral hydrate. JL3 induced a marked decrease of the firing rate of dorsal raphe serotonergic neu rons (ID50 = 3.87 +/- 0.57 mg kg(-1)) and of locus coeruleus noradrene rgic neurons (ID50 = 2.63 +/- 0.35 mg kg(-1)). The drug did not modify the electrical activity of A10 dopaminergic neurons. JL3 does not blo ck amine uptake but it has affinity for 5-HT1A and 5-HT2 receptors. It is speculated that serotonergic mechanisms could play a role in the e lectrophysiological effects of JL3.