Scientists discovered a few years ago that the hypothalamus that helps manage body temperature, hunger, sexual drive, sleep, etc. include neurons that express the protein OPSIN 3 (OPN3). However, what is far from clear is that this photosensitive protein is so deep inside the brain.
Posted in PNAS It shows that OPN3 plays an important role in regulating food consumption.
“Our results reveal a mechanism in which the non-visual OPSIN receptor OPN3 regulates food intake through the melanin corticotin 4 receptor MC4R, which is essential for regulating energy balance and feeding behavior,” Brown University Institute of Brain Sciences . “This finding is interesting because the loss-of-function mutation of MC4R is a known genetic cause of human obesity.”
The study was led by Hala Haddad, who was studied on his PhD. Student, then Brown Postdoctoral Research Assistant, Senior Author Oancea and Richard Lang, Director of the Cincinnati Children’s Visual Systems Group.
The team reported that OPN3 works with MC4R and KIR7.1 potassium channels to regulate certain cellular signals and to shoot neurons in key areas that control energy balance. It is worth noting that when mice lack OPN3 in this part of the hypothalamus, they had significantly less diet and were less active than control mice.
“We are excited to have the cellular mechanisms that OPN3 does in the brain for the first time,” Oancea said.
Opsin 3 has become the focus of Oancea lab research for nearly a decade, the team found it exists in melanocytes, which plays a role in pigmentation, and developed a mouse model to identify the protein Expression of specific brain regions. Researchers in Lang labs have also been studying OPN3 in adipose tissue and brain, mainly using mouse genetic tools. The two research teams began to work together around 2020.
Although their findings add important insights into OPN3’s function, the researchers say more research is needed to address whether the mechanism is also performed in a similar way in the human brain.
“Although we identified the mechanism and function of OPN3 in this area of the hypothalamus, the way this receptor works in other areas of the brain remains elusive,” Oancea said. “In different areas, OPN3 functions must have a common paradigm,” he said. We’re still looking for it.”
Furthermore, “current analysis cannot address the question of whether OPN3 can act as a light sensor in the brain of mice.” “This is yet to be addressed in future research.”
Oancea says dietary behavior and weight regulation is very complex.
“Figuring out how to solve these complex problems requires a broader understanding of the cellular processes involved,” she said.
The study was supported by Brown University Imaging Facility and Microscope Core, as well as the GMO and Genome Editing Core in Cincinnati Children. Funding for this study was from the National Institutes of Health (R01AR076241, R01EY027077, R01EY032029, R01EY032752, R01EY032566 and R01EY032566 and R01EY034456) and the National Science Foundation.
If you find this piece useful, consider supporting our work with a one-time or monthly donation. Your contribution allows us to continue to bring you accurate, thought-provoking scientific and medical news that you can trust. Independent reporting requires time, effort, and resources, and your support makes it possible for us to continue exploring stories that are important to you. Together, we can ensure that important discoveries and developments attract those who need them the most.
