Decoding the transcriptomic signatures of psychological trauma in human cortex and amygdala

Area of Science:

• Neuroscience
• Molecular Biology
• Psychiatry

Background:

• Psychological trauma significantly impacts brain function and increases psychiatric disorder risk.
• The precise molecular mechanisms linking trauma exposure to psychiatric vulnerability are not fully understood.

Purpose of the Study:

• To investigate the transcriptional signatures of various trauma exposures in specific human brain regions.
• To explore how different trauma types and sex influence these molecular changes.
• To identify potential gene targets and molecular pathways involved in trauma's long-term effects.

Main Methods:

• RNA sequencing of postmortem brain tissue from 304 donors (136 with trauma exposure).
• Analysis focused on dorsolateral prefrontal cortex, dorsal anterior cingulate cortex, medial amygdala, and basolateral amygdala.
• Cell-type-specific expression imputation and coexpression network analysis were employed.

Main Results:

• Amygdala regions showed vulnerability to childhood trauma, while cortical regions were more affected by adulthood trauma.
• Childhood trauma induced a strong transcriptional response in medial amygdala excitatory neurons.
• Trauma-associated coexpression modules revealed coordinated functional dysregulation and potential gene targets.

Conclusions:

• Traumatic experiences leave long-lasting molecular imprints on corticolimbic brain regions.
• Understanding these transcriptional signatures is crucial for dissecting the molecular basis of trauma-related psychiatric disorders.
• Findings highlight region-specific vulnerabilities and cellular responses to different types of trauma.