Novel findings from 2,838 Adult Brains on Sex Differences in Gray Matter Brain Volume

Abstract

There is still disagreement among studies with respect to the magnitude, location, and direction of sex differences of local gray matter volume (GMV) in the human brain. Here, we applied a state-of-the-art technique examining GMV in a well-powered sample (n = 2,838) validating effects in two independent general-population cohorts, age range 21-90 years, measured using the same MRI scanner. More GMV in women than in men was prominent in medial and lateral prefrontal areas, the superior temporal sulcus, the posterior insula, and orbitofrontal cortex. In contrast, more GMV in men than in women was detected in subcortical temporal structures, such as the amygdala, hippocampus, temporal pole, fusiform gyrus, visual primary cortex, and motor areas (premotor cortex, putamen, anterior cerebellum). The findings in this large-scale study may clarify previous inconsistencies and contribute to the understanding of sex-specific differences in cognition and behavior.

Figure 1

Significant sex differences for the combined cohort (n = 2,838). Glass brain projections with labels (top) and MNI-standard brain projections (bottom). Orange clusters display regions with larger gray matter volume in women (women > men): pCBH = posterior cerebellar hemisphere; IPL = inferior parietal lobe; SPL = superior parietal lobe; STS = superior temporal sulcus; ACC = anterior cingulate cortex; BA = Brodmann areas 45, 46, 47, 10; OFC = orbitofrontal cortex; pIns = posterior insula. Blue clusters display regions with significantly larger gray matter volume in men (men > women): BA = Brodmann areas 6, 17; aCBH = anterior cerebellar hemisphere, Hi = hippocampus, Th = thalamus, Pu = putamen, TP = temporal pole, FG = fusiform gyrus, Am = amygdala). All findings are significant at p ≤ 0.05, FWE corrected for multiple comparisons.