Nimodipine potentiates light-induced phase shifts of circadian activity rhythms but not c-fos expression in the suprachiasmatic nucleus of mice.
The present study assessed whether treatment with the L-type calcium channel antagonist nimodipine affects the responsiveness of the circadian pacemaker to light in C3H/HeN mice. Nimodipine (10 mg/kg, sc) increased the magnitude of light-induced phase delays (P<0.01) and c-fos mRNA expression in the paraventricular nuclei (P<0.01), but not in the suprachiasmatic nuclei (SCN). These results suggest that nimodipine may affect phase shifts of circadian activity rhythms through a mechanism independent of c-fos expression in the SCN.
Benloucif
Susan
S
Department of Molecular Pharmacology and Biological Chemistry, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA. s-benloucif@northwestern.edu
Masana
Monica I
MI
Zee
Phyllis C
PC
Dubocovich
Margarita L
ML
D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects* / Q000502:physiology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D016762:Genes, fos / Q000187:drug effects* / Q000502:physiology; D051379:Mice; D009553:Nimodipine / Q000494:pharmacology*; D010775:Photic Stimulation / Q000379:methods; D012333:RNA, Messenger / Q000096:biosynthesis; D013493:Suprachiasmatic Nucleus / Q000187:drug effects* / Q000378:metabolism
D012333:RNA, Messenger; D009553:Nimodipine