Chinese scientists reveal the mechanism of hypothalamic circadian rhythm December 25, 2018 Source: Ministry of Science and Technology Recently, the Huang Zhili Group of the School of Basic Medicine of Fudan University and the University of Hokkaido University of Japan, Sato and Musuke, published a book online in the Proceedings of the National Academy of Sciences of the United States of America (PNAS). Research paper on "Urtradian Calcium Rhythms in the Paraventricular Nucleus and Subparaventricular Zone in the Hypothalamus". The study found that the hypothalamic paraventricular nucleus and the paraventricular nucleus have secondary circadian rhythms, revealing the secondary circadian rhythm production site and neural network mechanism. Both plants and animals have their own biological rhythms. The most common is the 24-hour circadian rhythm. The human sleep-wake cycle conforms to the typical biological rhythm. However, in some behaviors and functions, mammals exhibit a rhythm with a period shorter than 24 hours, that is, a sub-circadian rhythm such as hormone secretion and thermoregulation in the human hypothalamus, REM-non-REM cycle at night, and the like. Because the secondary circadian rhythm and the circadian rhythm are often accompanied, the study of the secondary circadian rhythm is very difficult. Therefore, revealing the mechanism of the occurrence of the secondary circadian rhythm is an important and difficult scientific problem. To explore the specific mechanism of the circadian rhythm, the team expressed the calcium ion indicator GCaMP6s protein on the brain slices of newborn 4-6 days mice, which can be stimulated to produce fluorescence and dynamically change with intracellular calcium ions. A change in intensity occurs, and the degree of activity of the neuron is reflected by detecting the degree of calcium signal strength. Using real-time fluorescence imaging (Time-lapse imaging) to monitor changes in neuronal calcium ion concentration in isolated brain slices for more than one week, found in the hypothalamic paraventricular nucleus (PVN), paraventricular nucleus (SPZ) region and a part of the visual cross In the upper nucleus (SCN) region, there is a circadian rhythm with a period of 0.5 to 4 hours. This secondary circadian rhythm is generated from the SPZ-PVN region, and the secondary circadian signal can be fed back to the circadian SCN. In addition, the project team also discovered through pharmacological methods that the glutamatergic system is also involved in the formation of the circadian rhythm, while the sodium channel blocker TTX-sensitive neural network is involved in the synchronization of the secondary circadian calcium rhythm. The results of this study play an important role in understanding the secondary circadian rhythms of behaviors or functions such as sleep cycle, thermoregulation and hormone secretion in animals, and may provide potential treatments for biorhythmia and sleep disorders. Oxygen Mask,venturi mask,tracheostomy mask,nasal cannula 2 MEDS TECHONOLOGY CO.,LTD , https://www.2-meds.com