Altered grey matter volume in 'super smellers'

Area of Science:

• Neuroscience
• Olfactory neuroscience

Background:

• Heightened sense of smell, termed 'super smellers,' lacks detailed neuroanatomical data.
• The structural brain differences in individuals with superior olfaction are not well-understood.

Purpose of the Study:

• To investigate the neuroanatomical differences in gray matter volume (GMV) within the olfactory network of 'super smellers' compared to normosmic individuals.
• To explore the relationship between olfactory performance and brain structure in men with varying olfactory abilities.

Main Methods:

• A voxel-based morphometry study compared GMV in olfactory regions between 25 male 'super smellers' and 20 normosmic men.
• Participants were grouped based on standardized olfactory performance test scores.
• Key brain regions analyzed included the piriform/entorhinal cortex, orbitofrontal cortex, insula, and hippocampus.

Main Results:

• 'Super smellers' demonstrated significantly increased GMV in the anterior insula and the hippocampus (dentate gyrus) compared to normosmic men.
• Positive correlations were observed between hippocampal volume and olfactory performance in both groups.
• These findings highlight specific structural brain variations associated with superior olfactory function.

Conclusions:

• The anterior insula and hippocampus play crucial roles in olfactory information integration, odor learning, and memory.
• The neuroanatomical findings suggest that enhanced olfactory abilities may be linked to structural brain plasticity.
• Further research is needed to determine the genetic versus experience-based contributions to the observed neuroanatomical patterns in 'super smellers'.