Regulation of alpha7-nicotinic receptor subunit and alpha7-like gene expression in the prefrontal cortex of patients with bipolar disorder and schizophrenia

Acta Psychiatr Scand. 2006 Sep;114(3):211-5. doi: 10.1111/j.1600-0447.2006.00785.x.


Objective: The alpha7-nicotinic receptor subunit gene (CHRNA7) is located at chromosome 15q13-14, a region previously linked with schizophrenia. Genetic association and mRNA expression studies also implicate CHRNA7 in schizophrenia. The CHRNA7 gene has a partial duplication that constitutes the alpha7-like nicotinic receptor gene (CHRFAM7A). We hypothesized that major psychoses could affect the expression of both CHRNA7 and CHRFAM7A.

Method: CHRNA7 and CHRFAM7A mRNA levels were measured in postmortem prefrontal cortex (donated by the Stanley Foundation) from subjects with schizophrenia, bipolar disorder and unaffected controls (n = 35 each).

Results: The mRNA levels of alpha7 and alpha7-like genes have a positive correlation overall (r = 0.25; P = 0.009), however, there is no significant difference in the expression of CHRNA7 among the three diagnostic groups.

Conclusion: This correlation is driven by the bipolar group (r = 0.43; P = 0.009), and is absent in schizophrenia and unaffected controls, suggesting an alteration in the CHRNA7:CHRFAM7A ratio in bipolar disorder.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Bipolar Disorder / genetics*
  • Bipolar Disorder / pathology
  • Chromosomes, Human, Pair 15*
  • Female
  • Gene Duplication
  • Gene Expression / physiology*
  • Genetic Predisposition to Disease / genetics
  • Humans
  • Male
  • Middle Aged
  • Prefrontal Cortex / pathology*
  • RNA, Messenger / genetics
  • Receptors, Nicotinic / genetics*
  • Reference Values
  • Risk Factors
  • Schizophrenia / genetics*
  • Schizophrenia / pathology
  • Statistics as Topic


  • CHRNA9 protein, human
  • RNA, Messenger
  • Receptors, Nicotinic