The Neurobiology of Bipolar Disorder: Findings Using Human Postmortem Central Nervous System Tissue

Abstract

Objective: Postmortem brain studies have been undertaken to understand changes in the molecular architecture of the central nervous system (CNS) of subjects with bipolar disorder. These studies, along with a limited number of functional neuroimaging studies, have been reviewed to provide information on the neurobiology underlying the disorder. Method: Findings from the study of postmortem brain tissue and neuroimaging were reviewed if their focus was on the molecular architecture of the human CNS to identify future lines of research required to understand the underlying pathology of bipolar disorder. Results: There is considerable evidence to implicate the serotonergic system of the CNS and abnormalities in signal transduction pathways in the pathology of bipolar disorder. In addition, preliminary findings suggest that changes in the benzodiazepine binding site on the γ aminobutyric acid A receptor may be affected in bipolar disorder. Conclusions: Further systematic studies on the serotonergic systems of the CNS, as well as the interaction between neurotransmitter receptors, G-proteins and signal transduction pathways are required to better understand the pathology of bipolar disorder. In addition, findings on the serotonin transporter indicate that changes in presynaptic function may be a critical component of the pathology of bipolar disorder.