File(s) stored somewhere else

Please note: Linked content is NOT stored on Carnegie Mellon University and we can't guarantee its availability, quality, security or accept any liability.

Rhythmic regulation of membrane potential and potassium current persists in SCN neurons in the absence of environmental input.

journal contribution
posted on 01.08.2004, 00:00 by Sandra Kuhlman, Douglas G. McMahon

Neurons of the mammalian suprachiasmatic nucleus (SCN) generate self-sustained rhythms of action potential frequency having a period of approximately 24 h. It is generally believed that cell autonomous circadian oscillation of a network of biological clock genes drives the circadian rhythm in neuronal firing rate through as yet unspecified effects on the neuronal membrane. While it is clear that cyclic gene expression continues in constant darkness, previous studies have not examined which specific membrane properties of SCN neurons continue to oscillate in constant conditions. Here, we demonstrate that SCN neurons exhibit robust rhythms in resting membrane potential and input resistance in constant darkness. Furthermore, application of the K+ channel blocker tetraethylammonium revealed a rhythm in K+ current amplitude that persists in constant darkness and underlies the rhythm in membrane potential.