What Is the Suprachiasmatic Nucleus?

The supraoptic nucleus refers to the anterior hypothalamus nucleus. Located above the optic cross. It is a circadian pacemaker in the mammalian brain, which can regulate various circadian rhythm activities in the body, so that the internal environment can make the largest adaptation to the external environment in a suitable time sequence. As a pair structure, there is a nucleus on each side of the optic cross. There are two main areas: the ventrolateral area receives nerve fibers from the retinal hypothalamus bundle and the geniculate hypothalamus bundle, and also contains vasoactive intestinal peptides and europaparin neurons; Angiotensin and somatostatin neurons. ^[1]

Supraoptic nucleus

Right!

The supraoptic nucleus refers to the anterior hypothalamus nucleus. Located above the optic cross. It is a circadian pacemaker in the mammalian brain, which can regulate various circadian rhythm activities in the body, so that the internal environment can make the largest adaptation to the external environment in a suitable time sequence. As a pair structure, there is a nucleus on each side of the optic cross. There are two main areas: the ventrolateral area receives nerve fibers from the retinal hypothalamus bundle and the geniculate hypothalamus bundle, and also contains vasoactive intestinal peptides and europaparin neurons; Angiotensin and somatostatin neurons. ^[1]

The suprachiasmatic nucleus or suprachiasmatic nucleus (SCN) is

Supraoptic nucleation

From human birth to death, the phenomenon of biological rhythms runs through. SCN is the central structure for mammals to produce and regulate circadian rhythms. On the one hand, SCN has autonomous circadian rhythms such as electrophysiological characteristics, sugar utilization, and protein synthesis; on the other hand, SCN accepts integration of optical information from the external environment, synchronizing the internal rhythm of the organism with the external environment.

Humans or other animals have a fixed circadian rhythm in their physical activities such as eating, sleeping, and the control of this rhythm is in a part of the brain called the suprachiasmatic nucleus (SCN). SCN generally uses light to calibrate the circadian clock, but even in the absence of light, the neurons in the SCN keep the animal circadian: people and animals that are always in the dark environment usually continue to eat and sleep.

Supraoptic nuclear research

SCN regulation mechanism

Some scientists have found that neurons in the suprachiasmatic nucleus have cannabinoid receptors. A team led by Anthony van den Po of Yale University in the United States has conducted a new study to understand the role of these receptors. They first kept 42 mice in a completely dark environment for 2 weeks, and synchronized the rat's biological clock. In this environment, the mice developed a 12-hour activity and a rest period of 12 hours. Then, a few of the caged mice were exposed to light when they just woke up. Because mice are animals that move at night, the mice exposed to light will begin to move about 2 hours later. However, if mice were injected with cannabinoids before the light, the effect of delaying activities was much weaker, only an hour.
The researchers then studied the SCN neurons themselves. They cultured SCN cells in mice and added cannabinoids to the cells. They believe that it is likely that this increase in activity disrupted circadian rhythms in mice. In humans, cannabinoids may have a similar effect on the suprachiasmatic nucleus, causing SCN neurons in marijuana users to erroneously discharge, disrupting their own biological clock, and thus disrupting time.
Northwestern University in Evanston expert Joseph Bass said the study supports the claim that addictive drugs affect the circadian clock. It seems obvious in daily experience, but the previous Research has focused only on the brain's reward system. According to Bass, evidence is beginning to show that drug molecules affect both the reward system and the circadian system.