Increase of 5HT and VIP immunoreactivity within the hamster (Mesocricetus auratus) SCN during chronic MAOI treatment.
The effects of chronic treatment with the monoamine oxidase inhibitor (MAOI), clorgyline (CLG; 2 mg/kg per day) on serotonin (5HT) and vasoactive intestinal peptide (VIP) immunoreactivity (IR) within the hamster suprachiasmatic nucleus (SCN) were examined. Optical densities of 5HT IR and VIP IR were increased by MAOI treatment. VIP IR was increased in both the ventrolateral and dorsal regions of the SCN, suggesting that VIP content was increased within both perikarya and terminals of VIP neurons. The results suggest that previously described effects of MAOIs on the mammalian circadian system may be mediated in part, by their effects on serotonergic input to VIP neurons within the SCN.
Duncan
W C
WC
Clinical Psychobiology Branch, National Institute of Mental Health, NIH, Bethesda, MD 20892, USA. wduncan@box-w.nih.gov
Johnson
K A
KA
Wehr
T A
TA
D000818:Animals; D000906:Antibodies; D002940:Circadian Rhythm / Q000187:drug effects / Q000502:physiology; D003010:Clorgyline / Q000494:pharmacology*; D006224:Cricetinae; D008297:Male; D008647:Mesocricetus; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology*; D012701:Serotonin / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D013493:Suprachiasmatic Nucleus / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D014660:Vasoactive Intestinal Peptide / Q000032:analysis / Q000276:immunology / Q000378:metabolism*
D000906:Antibodies; D008996:Monoamine Oxidase Inhibitors; D012701:Serotonin; D014660:Vasoactive Intestinal Peptide; D003010:Clorgyline