Wednesday, June 7, 2017
Researchers pinpoint area of brain linked to bipolar disorder - NEUROSCIENCE
A volume decrease in specific parts of the brain’s hippocampus – long identified as a hub of mood and memory processing – was linked to bipolar disorder in a study led by researchers at The University of Texas Health Science Center at Houston (UTHealth). The research was published in Molecular Psychiatry, part of the Nature Publishing Group.
Bipolar I disorder is characterized by mood changes that can swing from a high-energy, manic state to a low-energy, depressive state. The disorder can affect sleep, energy level and the ability to think clearly, according to the National Institutes of Health. It can interfere with a person’s ability to work and perform daily living activities, and could lead to suicide attempts. Patients with bipolar II disorder do not experience the full-blown manic episodes, but may have a less severe high-energy state.
The research team used a combination of magnetic resonance imaging (MRI) and a state-of-the-art segmentation approach to discover differences in the volumes of subfields of the hippocampus, a seahorse-shaped region in the brain. Subjects with bipolar disorder were compared to healthy subjects and subjects with major depressive disorder.
Researchers found that subjects with bipolar disorder had reduced volumes in subfield 4 of the cornu ammonis (CA), two cellular layers and the tail portion of hippocampus. The reduction was more severe in patients with bipolar I disorder than other mood disorders investigated.
Further, in patients with bipolar I disorder, the volumes of certain areas such as the right CA 1 decreased as the illness duration increased. Volumes of other CA areas and hippocampal tail were more reduced in subjects who had more manic episodes.