Inhibition of protein kinase A phase delays the mammalian circadian clock.
The suprachiasmatic nuclei (SCN) contain the mammalian circadian clock whose rhythm of firing rate can be recorded in vitro for several days. Application of a protein kinase A (PKA) inhibitor onto the SCN at Zeitgeber time (ZT) 10 on the first day in vitro phase delayed the rhythm of firing rate expressed by SCN neurons on the subsequent day in vitro. Application of the inhibitor (Rp-cAMPS) at other circadian phases did not phase shift the rhythm. These results suggest that during approximately 1 h in the late subjective day the presence and activity of PKA plays a role in setting the phase of the mammalian circadian clock.
Departments of Psychology and Neuroscience Program, Smith College, Northampton, MA 01063, USA.
J M
JM
Lee
K M
KM
Schak
M E
ME
Harrington
D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects*; D006224:Cricetinae; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D008297:Male; D010766:Phosphorylation; D013493:Suprachiasmatic Nucleus / Q000187:drug effects* / Q000378:metabolism
D004791:Enzyme Inhibitors; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases