Localized alterations in pre- and postsynaptic serotonin binding sites in the ventrolateral prefrontal cortex of suicide victims

• Published in: Brain research 1995-08, Vol.688 (1), p.121-133
• Main Authors: Arango, Victoria, Underwood, Mark D., Gubbi, Ananda V., Mann, J. John
• Format: Article
• Language: English
• Subjects: 5-HIAA; 5-HT 1A receptor; [ 3H]8-OH-DPAT; [ 3H]Cyanoimipramine; Adult; Adult and adolescent clinical studies; Aging - metabolism; Autoradiography; Biological and medical sciences; Carrier Proteins - metabolism; Case-Control Studies; Female; HPLC; Humans; Male; Matched-Pair Analysis; Medical sciences; Membrane Glycoproteins - metabolism; Membrane Transport Proteins; Nerve Tissue Proteins - metabolism; Prefrontal Cortex - metabolism; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Quantitative receptor autoradiography; Radioligand Assay; Receptors, Presynaptic - metabolism; Receptors, Serotonin - metabolism; Risk Factors; Serotonin - metabolism; Serotonin Plasma Membrane Transport Proteins; Serotonin transporter; Sex Characteristics; Suicide
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/0006-8993(95)00523-S

Altered serotonin indices have been reported in the brain of suicide victims. We sought to localize the changes in presynaptic and postsynaptic serotonin receptors and identify an area of prefrontal cortex that may influence suicide risk. Quantitative autoradiography was performed in coronal sections of prefrontal cortex to determine whether serotonin 5-HT 1A receptor (postsynaptic in cortex) and serotonin transporter (presynaptic) binding are different in suicide victims compared to matched controls. 5-HT 1A receptor binding was higher in 85 of the 103 sampled areas in the suicide group ( n = 18 pairs; P < 0.0001). The increase ranged from 17 to 30%. The increase was more pronounced in the ventrolateral prefrontal cortex. Serotonin transporter binding was found to be lower in the suicide group in all but one of the 43 sampled regions ( n = 22 pairs; P < 0.0001). The reduction in binding was most pronounced in the ventrolateral prefrontal cortex, where the difference between suicides and controls ranged between 15 and 27%. Serotonin transporter and 5-HT 1A binding were negatively correlated ( r = −0.35 to − 0.44, P = 0.04 to 0.007) within the same brain areas, suggesting common regulatory factors with opposite effects on binding to the two receptors. We conclude that suicide victims have an abnormality in the serotonin system involving predominatly the ventrolateral prefrontal cortex, and hypothesize that the serotonergic dysfunction in this brain region contributes to the risk for suicidal behavior.