title: Effect of serotonin axon injury on the somatostatinergic system in rat frontoparietal cortex.
abstract: In order to investigate the possibility that, in the rat, some cerebral cortex somatostatin (SS) receptors may be localized presynaptically on the terminals of serotonergic neurons, serotonin [5-hydroxytryptamine, (5-HT)] neurons in the central nervous system were damaged with a local intracerebral injection of the serotonergic neurotoxin, 5,7-dihydroxytryptamine(5,7-DHT). The injection of 5,7-DHT (11 micrograms free base dissolved in 10 microliters of isotonic saline containing 0.01% ascorbic acid) in rats produced an reduction by about 74% in frontoparietal cortical 5-HT content at 1 and 3 weeks after injection. These changes were associated with a significant decrease by about 30% in the total number of specific SS receptors in the frontoparietal cortex at both times studied without influencing the apparent affinity of the receptors. Together, these results suggest that a portion of the frontoparietal cortex SS receptors may be localized presynaptically on the serotonergic nerve terminals. The 5,7-DHT did not affect SS-like immunoreactivity (SSLI) levels suggesting that SS and 5-HT are not colocalized within the same neuronal elements in the rat frontoparietal cortex.
authors.affiliation: Department of Biochemistry and Molecular Biology, Medical School, University of Alcalá, Madrid, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Muñoz-Acedo
authors.forename: S
authors.initials: S
authors.lastname: López-Sañudo
authors.forename: E
authors.initials: E
authors.lastname: Arilla
mesh_terms: D015116:5,7-Dihydroxytryptamine / Q000494:pharmacology; D000818:Animals; D001369:Axons / Q000187:drug effects / Q000378:metabolism*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D005625:Frontal Lobe / Q000378:metabolism; D009410:Nerve Degeneration / Q000187:drug effects / Q000502:physiology; D010296:Parietal Lobe / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017481:Receptors, Somatostatin / Q000187:drug effects / Q000378:metabolism*; D012044:Regression Analysis; D012701:Serotonin / Q000378:metabolism*
chemical_list: D017481:Receptors, Somatostatin; D015116:5,7-Dihydroxytryptamine; D012701:Serotonin