Circadian clock genes and respiratory neuroplasticity genes oscillate in the phrenic motor system.

Circadian clock genes and respiratory neuroplasticity genes oscillate in the phrenic motor system. Am J Physiol Regul Integr Comp Physiol. 2020 Apr 29;: Authors: Kelly MN, Smith DN, Sunshine MD, Ross A, Zhang X, Gumz ML, Esser KA, Mitchell GS Abstract Circadian rhythms are endogenous and entrainable daily patterns of physiology and behavior. Molecular mechanisms underlie circadian rhythms, characterized by an ~24-hour pattern of gene expression of core clock genes. Although it has long been known that breathing exhibits circadian rhythms, little is known concerning clock gene expression in any element of the neuromuscular system controlling breathing. Further, we know little concerning gene expression necessary for specific respiratory functions, such as phrenic motor plasticity. Thus, we tested the hypotheses that transcripts for clock genes (Bmal1, Clock, Per1 & Per2) and molecules necessary for phrenic motor plasticity (Htr2a, Htr2b, Bdnf & Ntrk2) oscillate in regions critical for phrenic/diaphragm motor function via RT-PCR. Tissues were collected from male Sprague-Dawley rats entrained to a 12-hour light-dark cycle at 4 zeitgeber times (ZT; n=8/group): ZT5, ZT11, ZT17 and ZT23; ZT0 = lights on. Here, we demonstrate that 1) circadian clock genes (Bmal1, Clock, Per1, Per2) oscillate in regions critical for phrenic/diaphragm function, including the caudal medulla, ventral C3-C5 cervical spinal cord, and diaphragm, 2) the clo...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - Category: Physiology Authors: Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research