Concurrent decrease of vasopressin and protein kinase Cα immunoreactivity during the light phase in the vole suprachiasmatic nucleus

• Published in: Neuroscience Letters
• Main Authors: Jansen, Koen, van der Zee, Eddy A., Gerkema, Menno P.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1998
• Subjects: Zeitgeber time; Immunocytochemistry; Protein kinase Cα; Suprachiasmatic nucleus; Vasopressin; Common vole; CIRCADIAN-RHYTHMS; IN-VITRO; RAT; NEURONS; RECEPTOR; MOUSE; AVP
• Online Access: https://hdl.handle.net/11370/1d4a990c-3e9d-48e2-a33f-6173b948d0a8; https://research.rug.nl/en/publications/1d4a990c-3e9d-48e2-a33f-6173b948d0a8; https://doi.org/10.1016/S0304-3940(98)00271-7; https://pure.rug.nl/ws/files/14659294/1998NeurosciLettJansen.pdf

Vasopressin (AVP) is a major neuropeptide in the suprachiasmatic nucleus, the mammalian hypothalamic circadian pacemaker. Protein kinase Cα is a putatively coupled intracellular messenger. Mean numbers of AVP- and protein kinase Cα-immunoreactive neurons were determined in the suprachiasmatic nucleus of common voles, entrained to a 12:12 h light-dark (LD) cycle, at the beginning of the light period (zeitgeber time zero) and 6 h later (zeitgeber time six). At zeitgeber time zero, mean numbers of AVP- and protein kinase Cα-immunoreactive neurons were 2194 and 9897, respectively. Both numbers decreased significantly with about 40% at zeitgeber time six. This concurrent decrease was most pronounced in the dorsomedial aspect of the suprachiasmatic nucleus. These findings are consistent with the findings of a peak of AVP release in rats during the early light phase.