GABAA receptor gamma subunits in the prefrontal cortex of patients with schizophrenia and bipolar disorder

Immunohistochemical and immunoblot techniques were employed in order to examine alterations of the GABAA receptor gamma subunits in the prefrontal cortex from postmortem subjects with schizophrenia and bipolar disorder. Immunohistochemically, gamma 1/3 immunolabeling in the neuronal soma in the prefrontal cortex from subjects with bipolar disorder was more intense than that of the controls and the subjects with schizophrenia. The intensity of gamma 1/3 immunolabeling of the schizophrenic subjects was comparable with that of the controls. Immunoblot analysis demonstrated a significant increase in the gamma 1 subunit in the bipolar subjects, whereas no remarkable difference was detected in the schizophrenic subjects. The present study suggests that the GABAA receptor gamma subunit is differentially involved in schizophrenia and bipolar disorder, and that the gamma subunit is up-regulated in the prefrontal cortex of subjects with bipolar disorder.