The impulse to like someone was previously attributed to the brain, to the hypothalamus to be exact. Now, a study reveals the neurons responsible to the attraction to opposite sex. The scent of the opposite sex triggers some certain hormone-sensitive neurons which trigger pro-social behavior.
The researchers found neurons which are sensitive to sex hormones in the hypothalamus of mice. Aside from pro-social behavior, these neurons could play a certain role in mood-related human conditions such as depression. This could lead to the development of new treatments targeting such conditions.
In a study published in Nature Neuroscience, researchers from University of North Carolina School of Medicine investigated the hypothalamus of mice using advanced deep brain imaging techniques. Specifically, the medial preoptic area (mPOA) of the brain. Previous research reveals that mPOA plays a vital role in reproductive and social behavior, however, it is unclear how this area drives social motivation.
The study focused on one of the major connections of the mPOA, which sends signals to the ventral tegmental area (VTA). They found out that a large subset of mPOA neurotensin neurons becomes active when the female mice were exposed to the scent of male mouse urine. But not with other attractive odors such as appetizing food or even female mouse urine odor. This implies the importance of the said neural network to attraction to opposite sex.
"With our setup, we could image the mice a couple of times a week and each time find the same cells that we previously recorded brain activity from," Garret D. Stuber, PhD, associate professor of psychiatry and cell biology & physiology and co-lead author of the study said according to Science Daily. "On the whole, the data suggest that these mPOA neurons help drive social attraction toward a potential mate," he added.
Other than the basic implication to neuroscience, the attraction to opposite sex, the study further highlighted the importance of the findings to psychological conditions like depression. In some females, changes in hormonal levels triggers or worsens mood-related behavior. The study of neural circuits which are sensitive to hormones could reveals new targets for treatment of mood disorders.