Autoradiographic localization of 5-HT1E and 5-HT1F binding sites in rat brain: effect of serotonergic lesioning.
5-carboxamidotryptamine (5-CT)-insensitive binding sites labelled by [3H]5-hydroxytryptamine (5-HT) in the presence of 100 nM 5-CT and 100 nM mesulergine, were examined by semi-quantitative autoradiography in rat brain. Under these conditions most of the labelled sites correspond to 5-HT1E and 5-HT1F sites. The 5-CT-insensitive binding is located mainly in cortical layer V, caudate-putamen, interpeduncular nucleus and claustrum. In cortex and caudate-putamen, a large proportion of 5-CT-insensitive sites is displaced by 250 nM sumatriptan and can be attributed to the presence of 5-HT1F receptors. A low, but significant, level of displacement by sumatriptan was observed in the choroid plexus. Lesions of serotonergic neurones by intracerebroventricular 5,7-dihydroxytryptamine injection does not significantly modify the densities of 5-HT1E or 5-HT1F binding sites. Our findings suggest that the 5-HT1F receptor has a limited distribution in rat brain, mainly located on non-serotonergic neurones.
Fugelli
A
A
Unité de Pharmacologie N.I.E, Institut Pasteur, Paris, France.
Moret
C
C
Fillion
G
G
D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000378:metabolism*; D008297:Male; D051381:Rats; D011985:Receptors, Serotonin / Q000032:analysis* / Q000378:metabolism; D012701:Serotonin / Q000494:pharmacology*; D014316:Tritium
D011985:Receptors, Serotonin; D014316:Tritium; D012701:Serotonin