SCI Disrupts Diurnal Rhythms (IMAGE) Society for Neuroscience Caption Figure 9. (A) Diurnal rhythm control under homeostatic conditions. Initial circadian input occurs via light activating specialized retinal ganglion cells that project directly to the suprachiasmatic nucleus (SCN). The SCN is the master circadian oscillator; in turn, this regulates extra-SCN ("peripheral") rhythms via direct and indirect routes. The SCN controls peripheral clocks directly via autonomic control (sympathetic and parasympathetic innervation), whereas the SCN controls peripheral clocks indirectly through regulation of physiologic and humoral factors. Appropriately entrained clocks throughout the body (likely every cell) optimize organismal performance for time-of-day. (B) Diurnal rhythm control is disrupted by SCI. Our data suggest that SCI disrupts rhythms of key zeitgebers - including body temperature, activity, and CORT (yellow bolts) - which could disrupt peripheral clock entrainment. In addition, data from other groups suggest that SCI also disrupts additional entraining factors (e.g., feeding, melatonin, and autonomic input; grey bolts). Ultimately, prolonged SCI-elicited disruption of these entraining factors could contribute to loss of homeostasis and suboptimal repair. Credit Gaudet et al., JNeurosci (2018) Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.