OPN3 expressing neurons (inexperienced) within the paraventricular nucleus of the hypothalamus. Picture courtesy of Jonathan Mercado-Reyes. Credit score: Jonathan Mercado-Reyes.
Scientists found years in the past that the hypothalamus—which helps to handle physique temperature, starvation, intercourse drive, sleep and extra—consists of neurons that specific the protein opsin 3 (OPN3). Far much less clear, nevertheless, was what this light-sensing protein does so deep contained in the mind.
A examine revealed in PNAS means that OPN3 performs an vital function in regulating meals consumption.
“Our results uncover a mechanism by which the nonvisual opsin receptor OPN3 modulates food intake via the melanocortin 4 receptor MC4R, which is crucial for regulating energy balance and feeding behavior,” mentioned Elena Oancea, a professor of medical science who’s affiliated with the Carney Institute for Mind Science at Brown College. “This finding is interesting because loss-of-function mutations in MC4R are a known genetic cause of obesity in humans.”
The examine was led by Hala Haddad, who carried out the analysis whereas a Ph.D. scholar after which postdoctoral analysis affiliate at Brown, with senior authors Oancea and Richard Lang, director of the Visible Techniques Group at Cincinnati Youngsters’s.
The analysis staff reported that OPN3 features along with MC4R and the Kir7.1 potassium channel to control sure cell indicators in addition to neuronal firing in a key space that controls vitality steadiness. Notably, when mice had been engineered to lack OPN3 on this a part of the hypothalamus, they ate considerably much less and had been much less lively than management mice.
“We’re very excited to have, for the first time, a cellular mechanism of what OPN3 is doing in the brain,” Oancea mentioned.
Opsin 3 has been the main target of analysis in Oancea’s lab for nearly a decade, and the staff has found that it’s current in melanocytes, the place it features in pigmentation, and has developed a mouse mannequin to establish the particular mind areas the place this protein is expressed. Researchers in Lang’s lab have additionally been finding out OPN3 in fats tissue and within the mind, primarily utilizing mouse genetics instruments. The 2 analysis groups began collaborating round 2020.
Whereas their findings add an vital perception into the operate of OPN3, the researchers mentioned extra examine is critical to deal with whether or not the mechanism additionally performs in comparable methods within the human mind.
“While we identified the mechanism and function of OPN3 in this region of the hypothalamus, how this receptor works in other areas of the brain remains elusive,” Oancea mentioned. “There must be a common paradigm for OPN3 function in different areas, and we’re still looking for that.”
Furthermore, “the current analysis does not resolve the question of whether OPN3 can function as a light sensor in the mouse brain,” Lang mentioned. “That remains to be addressed in future studies.”
The regulation of consuming habits and physique weight is extraordinarily advanced, Oancea mentioned.
“Figuring out how to address these complex issues requires a broader understanding of the cellular processes involved,” she mentioned.
Extra info:
Hala Ok. Haddad et al, Hypothalamic opsin 3 suppresses MC4R signaling and potentiates Kir7.1 to advertise meals consumption, Proceedings of the Nationwide Academy of Sciences (2025). DOI: 10.1073/pnas.2403891122
Supplied by
Brown College
Quotation:
Examine reveals opsin 3’s function in mouse urge for food management (2025, February 15)
retrieved 15 February 2025
from https://medicalxpress.com/information/2025-02-reveals-opsin-role-mouse-appetite.html
This doc is topic to copyright. Aside from any truthful dealing for the aim of personal examine or analysis, no
half could also be reproduced with out the written permission. The content material is supplied for info functions solely.
