Pea-sized area of the brain linked to schizophrenia risk

New research has provided new insight into how the habenula, a pea-sized brain region that helps regulate motivation and mood, may contribute to schizophrenia risk.

Many schizophrenia-related molecular changes appear to be specific to this region, suggesting the habenula could be a potential target for future treatments.

Researchers from the Lieber Institute for Brain Development and Johns Hopkins University used advanced molecular techniques to analyse postmortem human brains, creating the first cell-by-cell gene expression map of the human habenula — showing which genes are active in different cells.

Led by Ege A. Yalcinbas, PhD, the team compared brain tissue from 35 people with schizophrenia and 33 nonpsychiatric donors.

They focused on the habenula because of its emerging role in psychiatric disorders and its influence on neurotransmitter systems — the brain’s chemical messengers — affected in schizophrenia.

The analyses identified numerous genes with altered expression patterns, many unique to the habenula.

 Sixteen of these genes overlapped with those known to be associated with the development of schizophrenia, providing evidence that the habenula may contribute to the genetic architecture of the condition.

The researchers also found genes linked to nicotine dependence in the habenula — significant given the increased rates of smoking among people with schizophrenia.

AJP editor in chief Ned Kalin, MD said: “This work is important as it has uncovered alterations in the expression of specific genes in the habenula, a relatively under-investigated brain region, that may be related to the pathophysiology and/or aetiology of schizophrenia.”

The authors noted that the study could not determine cause and effect and was based on a small sample of men of European ancestry.

They recommend further research to confirm and extend these findings.