First Author | Trillat AC | Year | 1997 |
Journal | J Neurochem | Volume | 69 |
Issue | 5 | Pages | 2019-25 |
PubMed ID | 9349547 | Mgi Jnum | J:43716 |
Mgi Id | MGI:1098377 | Doi | 10.1046/j.1471-4159.1997.69052019.x |
Citation | Trillat AC, et al. (1997) Regulation of serotonin release in the frontal cortex and ventral hippocampus of homozygous mice lacking 5-HT1B receptors: in vivo microdialysis studies. J Neurochem 69(5):2019-25 |
abstractText | To assess the involvement of the serotonin receptor subtype 5-HT1B as terminal autoreceptor regulating 5-HT release in mice, we compared basal values and potassium-evoked changes of extracellular 5-HT levels obtained by in vivo microdialysis in two serotoninergic terminal projection areas of conscious wild-type mice with those measured in homozygous mutant mice lacking the gene encoding the 5-HT1B receptor. In the frontal cortex and ventral hippocampus, basal and K+-evoked 5-HT release did not differ between the two strains of mice studied. The infusion via reverse microdialysis of the selective 5-HT1B receptor agonist CP-93,129 (500 nM) decreased significantly K+-evoked 5-HT release in the frontal cortex (by -44%) and ventral hippocampus (by -32%) of wild-type mice but had no effect in mutants. In a similar manner, the mixed 5-HT1B-5-HT1D receptor agonist sumatriptan (800 nM) decreased significantly K+-evoked 5-HT release in the frontal cortex (by -46%) of wild-type mice but had no effect in mutants. These results demonstrated that 5-HT1B knockout mice are not as sensitive to full (CP-93,129) and mixed (sumatriptan) 5-HT1B receptor agonists as are wild-type mice. These data provide in vivo evidence that, in mice, 5-HT1B, but not 5-HT1D, autoreceptors inhibit 5-HT release at nerve terminals located in the frontal cortex and ventral hippocampus. |