Alterations of serotonin receptor binding in the hypothalamus following acute denervation.
Quantitative autoradiography was used to determine the effect of acute serotonergic denervation with 5,7-dihydroxytryptamine (5,7-DHT) or serotonin 5HT1a and 5-HT1b receptors in male rats. Seven days after intrahypothalamic 5,7-DHT injection there was a significant increase in the density of 5HT1a receptors in the ventromedial and dorsomedial hypothalamic nuclei (VMN and DMN) of male rats. In adjacent sections. 5-HT1b receptors were significantly increased only in the VMN. No changes in receptor density were observed in the lateral hypothalamic area or hippocampus even though binding of [3H]paroxetine, which labels the presynaptic transporter site, was significantly decreased in all evaluated brain regions in 5,7-DHT-treated animals. In addition to demonstrating that 5-HT1a and 5-HT1b receptors are differentially regulated in different brain areas, these results show that in the brain regions examined both 5-HT1a and 5-HT1b receptors are primarily post-synaptic.
Frankfurt
M
M
Rockefeller University, New York, NY 10021.
Mendelson
S D
SD
McKittrick
C R
CR
McEwen
B S
BS
D015116:5,7-Dihydroxytryptamine / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D001369:Axons / Q000187:drug effects; D003714:Denervation; D004302:Dorsomedial Hypothalamic Nucleus / Q000378:metabolism; D006624:Hippocampus / Q000502:physiology; D007026:Hypothalamic Area, Lateral; D007031:Hypothalamus / Q000378:metabolism*; D007267:Injections; D008024:Ligands; D008297:Male; D017374:Paroxetine / Q000378:metabolism; D051381:Rats; D011985:Receptors, Serotonin / Q000378:metabolism*; D014697:Ventromedial Hypothalamic Nucleus / Q000378:metabolism
D008024:Ligands; D011985:Receptors, Serotonin; D015116:5,7-Dihydroxytryptamine; D017374:Paroxetine