Introduction
The circadian rhythm is a biological system that allows organisms to synchronize their activities to the coming and going of light in their external environment. All living organisms contain this biological clock that helps coordinate physiological activities, such as eating, sleeping, and reproducing, to promote survival. In mammals, the principal regulator of the circadian clock is a group of nerve cells known as the suprachiasmatic nucleus (SCN), which is located in the hypothalamus, an area found at the base of the brain that is responsible for controlling the endocrine system. The SCN is connected to the nerve cells in the eyes that send signals to SCN cells when they sense the presence or absence of light. When optic nerve cells sense light in the daytime, SCN cells send efferents in the form of hormones and neuronal signals to the rest of the body as well as to other regions of the brain that, for example, increase blood pressure and body temperature and decrease levels of melatonin. And when optic nerve cells sense a decrease in the amount of light, SCN cells send out signals that do the opposite [1, 2].
The circadian clock functions on the molecular level through two gene regulatory proteins, CLOCK and BMAL1. During the day, CLOCK and …show more content…
Staining is performed in the presence of Fc Block (eBioscience) at a 1:200 dilution on FACs buffer containing 2 mM EDTA and 5% FBS. Cells are stained with the following antibodies: FITC-PDCA (Miltenyi Biotec), PE-IRF7 (eBioscience), PE-Cy7-CD11C (BioLegend), PerCPCy5.5-F480 (Biolegend), and APC-CD45 (BD Biosciences). Cells are stained for 30 minutes on ice in the dark followed by rinsing in PBS. Cells are then run on the BD LSRII flow cytometer (BD