Isapirone is a partial agonist at 5-hydroxytryptamine 1A (5-HT1A) receptors in the rat hippocampus: electrophysiological evidence.
Using iontophoretic techniques we observed that in vivo isapirone (TVX Q 7821), a selective ligand for the 5-HT1A binding site, at low ejection currents (5-30 nA) antagonised 5-HT and 8-hydroxy-2-(di-n-propylamino) tetralin (DPAT)-induced suppression of hippocampal unit activity, with little effect on baseline firing rate itself. At higher ejection currents (20-100 nA) or following prolonged application, isapirone inhibited unit firing. Responses to GABA were unaffected by isapirone. These data demonstrate that isapirone is a 5-HT1A receptor antagonist with partial agonist properties on 5-HT sensitive neurones in the rat hippocampus.
D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D004594:Electrophysiology; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D011743:Pyrimidines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects*
D014151:Anti-Anxiety Agents; D011743:Pyrimidines; D011985:Receptors, Serotonin; C043077:ipsapirone