Transcriptomic analysis of the human habenula in schizophrenia

Area of Science:

• Neuroscience
• Genetics
• Psychiatry

Background:

• The habenula (Hb) plays a crucial role in neuropsychiatric disorders, including schizophrenia (SCZD).
• Understanding the cell type-specific molecular organization of the human Hb is vital for developing targeted therapies.
• Current knowledge of human Hb transcriptomics and its alterations in SCZD is limited.

Purpose of the Study:

• To define the molecular neuroanatomy of the human Hb.
• To identify transcriptomic changes in the human Hb associated with SCZD.
• To explore the genetic underpinnings of SCZD risk within the human Hb.

Main Methods:

• Single nucleus RNA-sequencing (snRNA-seq) on human Hb tissue to identify cell types.
• Single molecule fluorescent in situ hybridization (smFISH) for spatial mapping of identified cell types.
• Bulk RNA-sequencing and eQTL analysis on human Hb tissue from SCZD patients and controls to identify differentially expressed genes and genetic variants.

Main Results:

• Identified 17 distinct molecularly defined Hb cell types, including conserved rodent populations.
• Discovered 45 SCZD-associated differentially expressed genes (DEGs) in Hb-enriched tissue, with a majority unique to this region.
• Identified 16 colocalized genes between SCZD risk variants and DEGs, suggesting specific genetic links to SCZD.

Conclusions:

• The human Hb exhibits topographically organized cell types with unique molecular signatures.
• Distinct genetic changes in the human Hb are associated with SCZD.
• These findings offer novel molecular insights into the Hb's role in neuropsychiatric disorders and potential therapeutic targets.