Intraventricular galanin produces a time-dependent modulation of 5-HT1A receptors in the dorsal raphe of the rat

• Published in: Neuroreport Vol. 11; no. 18; p. 3943
• Main Authors: Razani, H, Diaz-Cabiale, Z, Fuxe, K, Ogren, S O
• Format: Journal Article
• Language: English
• Published: England 18.12.2000
• Subjects: 8-Hydroxy-2-(di-n-propylamino)tetralin - pharmacology; Animals; Binding Sites - drug effects; Binding Sites - physiology; Drug Administration Schedule; Galanin - pharmacology; Injections, Intraventricular; Male; Neurons - cytology; Neurons - drug effects; Neurons - metabolism; Radioligand Assay - statistics & numerical data; Raphe Nuclei - cytology; Raphe Nuclei - drug effects; Raphe Nuclei - metabolism; Rats; Rats, Sprague-Dawley; Receptors, Serotonin - drug effects; Receptors, Serotonin - metabolism; Receptors, Serotonin, 5-HT1; Time Factors; Tritium
• ISSN: 0959-4965
• DOI: 10.1097/00001756-200012180-00008

Galanin given i.c.v. increased the K(D) values of 5-HT1A receptors in the DR by 100% 10 min after administration. This effect had disappeared 2 h and 5 h after galanin administration. In contrast, i.c.v. galanin caused a 40% increase in the Bmax values at 2 h without affecting the Bmax values 10 min and 5 h after i.c.v. galanin. The mRNA levels of 5-HT1A receptors and of galanin in the DR were significantly decreased by 33% and 56% respectively 2h but not 5h after i.c.v. galanin. These results suggest that in vivo galanin can modulate somatodendritic 5-HT1A receptors in the DR in a time-dependent manner via galanin-5-HT1A receptor interactions. The findings implicate a potential role of galanin in affective disorders.