Cagampang F R, Antoni F A, Smith S M, Piggins H D, Coen C W
Anatomy and Human Biology, Division of Biomedical Sciences, King's College London, London, WC2R 2LS, UK.
Brain Res. 1998 Nov 9;810(1-2):279-82. doi: 10.1016/s0006-8993(98)00934-2.
Circadian functions of the suprachiasmatic nuclei (SCN) are influenced by cyclic AMP (cAMP). Adenylyl cyclase type II (AC-II) is a cAMP-generating enzyme which, in the context of activation by Gsalpha, is further stimulated by protein kinase C or G protein betagamma subunits. Using in situ hybridization we have found a biphasic variation in AC-II mRNA within the rat SCN during the light-dark cycle (peaks at Zeitgeber time 6 and 18) and also in constant darkness (peaks at circadian time 2 and 14). The cingulate cortex showed no such variation. These findings suggest that circadian changes in AC-II expression may be pertinent to the rhythmic functions of the SCN.
