Altered morphological traits along central olfactory centres in congenitally blind subjects.

Abstract

It is well documented that early sensory loss typically alters brain morphology in the areas associated with the lost sense. However, much less is known about the impact of early sensory loss on the remainder of the sensory regions. Therefore, we investigated whether congenitally blind (CB) individuals show brain alterations in the olfactory system by comparing cortical morphology and olfactory bulb (OB) volume between 16 congenitally blind individuals and 16 sighted matched controls. Our results showed that not only CB blind individuals exhibited smaller OB but also alterations of cortical density in some higher olfactory processing centres, but unchanged cortical thickness. Our current findings suggest that a lifelong absence of visual input leads to morphological alterations in olfactory processing areas.