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Updated: May 9, 2026
08:42
Whole Mount Labeling of Cilia in the Main Olfactory System of Mice
Published on: December 27, 2014
Brain structure is changed in congenital anosmia
Johannes Frasnelli1, Therese Fark, Jacqueline Lehmann
1CERNEC, Département de Psychologie, Université de Montréal, Montréal, Québec, Canada; Smell & Taste Clinic, Department of ENT, Technical University of Dresden Medical School, Dresden, Germany.
Neuroimage
|August 10, 2013
Summary
Congenital anosmia, or the inability to smell from birth, is linked to increased gray matter volume and cortical thickness in olfactory processing areas. This suggests reduced synaptic pruning due to lack of sensory input.
Area of Science:
- Neuroscience
- Neuroimaging
- Olfactory System Research
Background:
- Olfactory function in healthy individuals correlates with brain structure.
- The impact of congenital anosmia on higher-order olfactory processing areas remains unclear.
- Previous studies on acquired anosmia show reduced brain volumes, contrasting with potential effects of congenital loss.
Purpose of the Study:
- To investigate the effects of congenital anosmia on brain structure, specifically gray matter volume and cortical thickness in olfactory processing regions.
- To compare brain structure in individuals with congenital anosmia to healthy controls.
Main Methods:
- Acquired T1-weighted magnetic resonance images (MRIs) from 17 subjects with congenital anosmia and 17 age- and sex-matched controls.
- Compared white matter and gray matter volumes between groups.
- Assessed cortical thickness in olfactory processing areas.
Main Results:
- Subjects with congenital anosmia showed larger gray matter volumes in the left entorhinal and piriform cortices.
- Individuals with congenital anosmia had thicker orbitofrontal cortices bilaterally.
- The left piriform cortex was also thicker in the congenital anosmia group compared to controls.
Conclusions:
- Congenital anosmia is associated with increased gray matter volume and cortical thickness in olfactory processing areas.
- These findings contrast with observations in acquired anosmia and align with theories of reduced synaptic pruning in sensory systems with congenital loss.
- Suggests that reduced synaptic pruning due to absent peripheral sensory input may influence brain structure development in the olfactory system.
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