Cortical Gyrification in Transgender Individuals

Area of Science:

• Neuroscience
• Psychiatry
• Developmental Biology

Background:

• Gender incongruence (GI) involves estrangement from one's own body, often seen in transgender individuals.
• Current understanding of the neurobiological mechanisms underlying GI is limited.
• Previous models focused on sex atypical cerebral dimorphism, but a new model considers brain circuit disconnection in body perception.

Purpose of the Study:

• To investigate the neurobiological underpinnings of gender incongruence (GI) in transgender persons (TGI).
• To test a novel model proposing that GI is associated with altered brain circuits for body perception and self-ownership.
• To examine cortical gyrification as a metric of early brain maturation in relation to GI.

Main Methods:

• Magnetic Resonance Imaging (MRI) was used to measure cortical gyrification.
• The study included hormone-naive transgender men (TrM), transgender women (TrW), cisgender men (cismen), and cisgender women (ciswomen).
• Cortical gyrification was analyzed in relation to body-self incongruence.

Main Results:

• Transgender participants exhibited significantly lower cortical gyrification compared to cisgender participants.
• This reduction was specifically observed in the occipito-parietal and sensory motor cortex, regions crucial for body image and ownership.
• Cortical gyrification showed an inverse correlation with body-self incongruence in these specific brain regions.

Conclusions:

• Gender incongruence in transgender individuals may originate from neurodevelopmental factors affecting body image and ownership processing regions.
• These findings suggest a neurobiological basis for GI related to the development of body-self perception.
• The study contributes to understanding the neurobiological contributors to gender identity.