August 21, 2015

Brain circuitry in psychosis

Functional magnetic resonance imaging has revealed faulty circuits between the thalamus – a central hub of brain activity – and other brain regions.

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Growing evidence suggests that the thalamus – a central “hub” of brain activity – is abnormal in psychotic disorders. Key features of thalamic dysconnectivity in psychosis, including its onset, anatomical specificity and clinical correlates, are not well understood.

Neil Woodward, Ph.D., and Stephan Heckers, M.D., used resting state functional magnetic resonance imaging (fMRI) to study functional connectivity between the thalamus and cerebral cortex in healthy subjects and individuals with psychosis.

They confirmed previous reports of reduced connectivity between the thalamus and prefrontal cortex and increased somatomotor-thalamic connectivity, and they found the same pattern of altered circuitry in patients with both early-stage and chronic psychosis. The study revealed that thalamocortical dysconnectivity in psychosis includes reduced thalamic connection with the executive control network of the cortex and is related to cognitive impairment.

The findings, reported in Biological Psychiatry, are consistent with neurodevelopmental explanations for thalamic dysconnectivity in psychosis and clarify the anatomical specificity of thalamic circuitry abnormalities.

This research was supported by the National Institutes of Health (grants MH102266, MH070560, RR024975), the Jack Martin M.D. Research Professorship in Psychopharmacology, and the Brain and Behavior Research Foundation.

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