Identification of Two Brain Cell Types That Shape Our Response to Smells

Researchers from the University of Florida have uncovered the neural mechanisms that determine whether a scent is perceived as pleasant or unpleasant. The study, published in "Molecular Psychiatry," reveals that specific brain cell types in the amygdala play a pivotal role in assigning emotional significance to odors. These cells, found in the basolateral amygdala (BLA), are genetically distinct and capable of influencing our emotional reactions toward smells, whether positive or negative.

Traditionally, it's been understood that smells exert a powerful influence on our emotions and memory, but the precise brain circuitry linking olfactory perception with emotional responses was not fully understood. The amygdala, a small yet key brain region responsible for processing emotions, receives direct input from the olfactory system, making it a crucial area for studying scent-related emotional responses.

Using mice models that share neurochemical similarities with humans, the team observed that these animals could learn to classify odors as appealing or repulsive. By examining their brain activity, the researchers identified two distinct cell types within the BLA—one expressing Drd1+ and the other Drd2+ receptors—that are responsible for mediating these emotional associations.

Interestingly, the findings suggest that these cells are not fixed in their role; instead, they possess the capability to produce either positive or negative emotional responses depending on where they project in the brain and how they interact with other neural structures. This flexibility means an odor's emotional valence is dynamically constructed rather than hardwired.

Understanding how the brain categorizes smells has significant implications, especially for individuals with heightened sensory sensitivities, such as those with PTSD, anxiety, or autism spectrum disorder. These individuals might experience exaggerated reactions to certain odors, affecting their daily lives. The research offers hope that future therapeutic strategies could target these specific neural pathways to modulate emotional responses to olfactory stimuli.

Potential treatments may involve medication or neural modulation techniques designed to suppress or activate these pathways, helping individuals gain control over adverse scent associations or restore enjoyment where it has been lost. Ultimately, this research advances our understanding of the biological basis of emotional processing related to our strongest sense and could lead to improved interventions for sensory-related emotional disorders.

Source: https://medicalxpress.com/news/2025-06-brain-cell-pleasant-unpleasant.html