Water and metabolite transverse T2 relaxation time abnormalities in the white matter in schizophrenia

Area of Science:

• Neuroimaging
• Neuroscience
• Biochemistry

Background:

• White matter microstructural abnormalities are implicated in schizophrenia pathophysiology.
• Diffusion MRI is commonly used, but transverse relaxation times (T2) offer complementary insights into molecular interactions.
• Water and N-acetylaspartate (NAA) T2 values reflect distinct intra- and extracellular processes.

Purpose of the Study:

• To investigate differences in water and NAA T2 relaxation times in the white matter of patients with schizophrenia (SZ) compared to healthy controls (HC).
• To explore the relationship between T2 relaxation times and white matter microenvironment alterations in schizophrenia.

Main Methods:

• Collected water and NAA T2 data from 16 HC and 16 SZ subjects.
• Utilized 4 Tesla (4 T) magnetic resonance imaging (MRI).
• Focused analysis on a 9 cm(3) voxel in the right prefrontal white matter.

Main Results:

• The SZ group exhibited significantly longer water T2 relaxation times compared to the HC group.
• The SZ group showed significantly shorter NAA T2 relaxation times compared to the HC group.
• A significant metabolite × group interaction was observed (F(18,1):4.980, p=0.039).

Conclusions:

• The observed pattern of prolonged water T2 and shortened NAA T2 suggests impoverished white matter macromolecule structures, potentially including myelin.
• Findings indicate abnormal intra-axonal milieu and volume in the white matter of individuals with schizophrenia.
• T2 relaxation times provide valuable information on molecular and microstructural changes in schizophrenia.