Serotonin depletion by 5,7-dihydroxytryptamine does not affect G protein subunit levels in rat cortex.
To investigate the role of G proteins in denervation supersensitivity of the CNS serotonergic system, we examined the effect of lesioning serotonergic neurons on the abundance of cerebral cortical membrane G protein subunits in rats. Three weeks after intracisternal injection of 5,7-dihydroxytryptamine (5,7-DHT), which significantly reduced cortical 5-hydroxytryptamine (5-HT; -90%) and 5-hydroxyindoleacetic acid (approximately 98%) levels, no statistically significant differences were observed for G alpha s-1, G alpha s-s, G alpha i1, G alpha i2, G alpha q/11, G alpha 0, G beta 1 and G beta 2 immunoreactivity levels between sham-lesioned and 5,7-DHT lesioned rats. These data suggest that the functional supersensitivity of 5-HT neuronal system often observed following lesions of 5-HT fibers may not involve changes at the level of G proteins but may instead encompass other downstream elements of the 5-HT receptor signaling cascade.
D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D004102:Dihydroxytryptamines / Q000494:pharmacology*; D019204:GTP-Binding Proteins / Q000096:biosynthesis* / Q000378:metabolism; D007278:Injections, Spinal; D008297:Male; D009474:Neurons / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism*; D015398:Signal Transduction; D013997:Time Factors
D004102:Dihydroxytryptamines; D012701:Serotonin; D019204:GTP-Binding Proteins