Diurnal variation in serotonin immunoreactivity in the dorsal raphe nucleus.
Serotonin (5-HT) immunostained sections were analyzed using integrated optical density (IOD) measures obtained throughout the dorsal raphe nucleus (DRN) in Mongolian gerbils at selected times during a 12:12 h light:dark cycle. Substantial diurnal variation occurred in 5-HT neuronal staining density, with lowest and highest IOD values occurring at the light/dark and dark/light transitions, respectively. The injection of pargyline and tryptophan increased 5-HT immunostaining comparable to the highest level observed in control animals. Transitions between light and dark periods appear to be major environmental events that influence 5-HT levels in the DRN.
Birkett
Melissa
M
Department of Neuroscience and Behavior Program, Tobin Hall, University of Massachusetts, Amherst, MA 01003-9271, USA.
Fite
Katherine V
KV
D000818:Animals; D018687:Antidepressive Agents, Second-Generation / Q000494:pharmacology; D002940:Circadian Rhythm / Q000502:physiology*; D003624:Darkness; D001330:Electronic Data Processing; D005849:Gerbillinae; D007150:Immunohistochemistry; D008027:Light; D008297:Male; D008636:Mesencephalon / Q000166:cytology / Q000378:metabolism*; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D010293:Pargyline / Q000494:pharmacology; D011903:Raphe Nuclei / Q000166:cytology / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism*; D014364:Tryptophan / Q000494:pharmacology
D018687:Antidepressive Agents, Second-Generation; D008996:Monoamine Oxidase Inhibitors; D012701:Serotonin; D014364:Tryptophan; D010293:Pargyline