Gray Matter Microstructural Abnormalities and Working Memory Deficits in Individuals with Schizophrenia

Area of Science:

• Neuroimaging
• Psychiatry
• Neuroscience

Background:

• Working memory impairments are key indicators in schizophrenia prognosis.
• Gray matter (GM) volume and thickness are typically associated with working memory deficits.

Purpose of the Study:

• To investigate the relationship between gray matter (GM) diffusivity and working memory in individuals with schizophrenia and healthy controls.
• To identify specific brain regions where GM microstructural differences may underlie working memory impairments in schizophrenia.

Main Methods:

• Collected T1 and diffusion tensor imaging (DTI) data, working memory scores (letter-number sequencing), and demographic information from 90 individuals with schizophrenia and 97 controls.
• Parcellated T1 images into 68 GM Regions of Interest (ROIs) and calculated diffusion parameters (Axial Diffusivity (AD), Fractional Anisotropy (FA), Radial Diffusivity (RD), and Trace (TR)) for each ROI.

Main Results:

• Individuals with schizophrenia exhibited significantly higher AD, RD, and TR in frontal, temporal, and anterior cingulate regions compared to controls.
• In schizophrenia patients, working memory performance negatively correlated with AD, RD, and TR in specific left hemisphere regions, including the lateral orbitofrontal, superior temporal, inferior temporal, and rostral anterior cingulate areas.

Conclusions:

• Gray matter (GM) microstructural abnormalities are present in the frontal, temporal, and anterior cingulate regions of individuals with schizophrenia.
• These GM microstructural alterations provide a potential neuropathological explanation for the observed working memory deficits in schizophrenia.