Serotonin depletion by 5,7-dihydroxytryptamine does not affect G protein subunit levels in rat cortex

• Published in: Neuroscience letters 1995-07, Vol.194 (3), p.153-156
• Main Authors: Li, Peter P., Law, Garson, Green, Marty, Chambers, John W., Coscina, Donald V., Warsh, Jerry J.
• Format: Article
• Language: English
• Subjects: 5,7-Dihydroxytryptamine; Animals; Biochemistry and metabolism; Biological and medical sciences; Central nervous system; Cerebral Cortex - drug effects; Cerebral Cortex - metabolism; Denervation supersensitivity; Dihydroxytryptamines - pharmacology; Fundamental and applied biological sciences. Psychology; G proteins; GTP-Binding Proteins - biosynthesis; GTP-Binding Proteins - metabolism; Injections, Spinal; Male; Neurons - drug effects; Rats; Rats, Sprague-Dawley; Serotonin; Serotonin - metabolism; Signal Transduction; Time Factors; Vertebrates: nervous system and sense organs
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/0304-3940(95)11746-J

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 (∼98%) levels, no statistically significant differences were observed for G α s-1, G α s-s, G α i1, G α i2, G α q/11, G α o, and G β1 and G β2 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.