Abnormal functional connectivity of the medial cortex in euthymic bipolar II disorder

Prog Neuropsychopharmacol Biol Psychiatry. 2014 Jun 3:51:28-33. doi: 10.1016/j.pnpbp.2014.01.004. Epub 2014 Jan 16.

Abstract

This project utilized functional MRI (fMRI) and a motor activation paradigm to investigate neural circuitry in euthymic bipolar II disorder. We hypothesized that circuitry involving the cortical midline structures (CMS) would demonstrate abnormal functional connectivity. Nineteen subjects with recurrent bipolar disorder and 18 controls were studied using fMRI and a motor activation paradigm. We used functional connectivity analyses to identify circuits with aberrant connectivity. We found increased functional connectivity among bipolar subjects compared to healthy controls in two CMS circuits. One circuit included the medial aspect of the left superior frontal gyrus and the dorsolateral region of the left superior frontal gyrus. The other included the medial aspect of the right superior frontal gyrus, the dorsolateral region of the left superior frontal gyrus and the right medial frontal gyrus and surrounding region. Our results indicate that CMS circuit dysfunction persists in the euthymic state and thus may represent trait pathology. Future studies should address whether these circuits contribute to relapse of illness. Our results also suggest the possibility that aberrations of superior frontal circuitry may impact default mode network and cognitive processes.

Keywords: Bipolar disorder; Functional MRI; Medial cortex.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Bipolar Disorder / pathology*
  • Cerebral Cortex / blood supply
  • Cerebral Cortex / pathology*
  • Cerebral Cortex / physiopathology*
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging
  • Male
  • Motor Activity / physiology
  • Neural Pathways / blood supply
  • Neural Pathways / physiology*
  • Oxygen / blood
  • Young Adult

Substances

  • Oxygen