Thalamic transcriptome screening in three psychiatric states.

Area of Science:

• Neuroscience
• Genetics
• Psychiatry

Background:

• The prefrontal cortex is linked to schizophrenia and affective disorders.
• Thalamic nuclei and cortical fields function as interconnected units.
• Altered thalamic gene expression is anticipated alongside cortical dysfunction.

Purpose of the Study:

• To investigate genome-wide gene expression in thalamic neurons projecting to the dorsolateral prefrontal cortex.
• To compare gene expression patterns in schizophrenia, major depression, and bipolar disorder against controls.

Main Methods:

• Laser-capture microdissection (LCM) was used to harvest neurons.
• Whole-genome expression screening was performed using microarrays.
• Analysis focused on thalamic neurons connecting to the dorsolateral prefrontal cortex.

Main Results:

• Schizophrenia (SZ) exhibited the highest number of dysregulated genes (1152), followed by major depression (MD) (385) and bipolar disorder (BP) (288).
• Distinct gene pathways were uniquely altered in each disorder: SZ (IGF1-mTOR, AKT, RAS, VEGF, Wnt, immune signaling, eIF2, proteasome), BP (Vitamin D receptor, calcium signaling), and MD (AKAP95 pathway, pantothenate and CoA biosynthesis).
• Significant transcriptional differences were observed among the three psychiatric disorders in thalamic neurons.

Conclusions:

• These findings reveal unique transcriptional dysregulation patterns in the thalamus specific to schizophrenia, bipolar disorder, and major depression.
• The study provides novel insights into the molecular mechanisms underlying thalamic dysfunction in these psychiatric conditions.