Tech Daily News (Reporter: Zhang Jiaxin) Why can some people easily stop eating when they are full, while others can't seem to stop, potentially leading to obesity? A study from Northwestern University in the United States suggests that one reason may lie in the brain circuitry. Newly discovered structural connections between two areas in the brain may be related to regulating eating behavior. These areas involve olfaction and behavioral motivation. The weaker the connection between these two brain regions, the higher the body mass index (BMI) tends to be. This study was published on May 16th in the "Journal of Neuroscience."
Researchers identified a connection between the olfactory tubercle and the periaqueductal gray (PAG) around the midbrain. The olfactory tubercle is an area of the olfactory cortex and part of the brain's reward system. The PAG is involved in motivating behaviors in response to negative emotions such as pain and threat, and may play a role in inhibiting eating.
When hungry, the aroma of food can whet one's appetite. However, when full, this scent may not be as appealing. Odors play a crucial role in guiding behaviors like food intake, and conversely, olfaction is regulated by hunger levels. Scientists have yet to fully understand the neural mechanisms by which olfaction influences eating.
Assistant Professor Zhou Guangyu from Northwestern University's Feinberg School of Medicine Neurology Research stated that the desire to eat is related to the attractiveness of food odors, but if the brain circuits guiding this behavior are disrupted, signals may be confused, leading to food remaining appealing even when full. When the structural connection between the olfactory tubercle and PAG in the brain is weak, an individual's BMI level tends to increase.
