The significance of Kİ67, glial fibrillary acidic protein and vitamin D receptor in the central nervous system of postmortem suicide victims

Death by suicide is a tragic public health concern. Some of these victims are patients with major depressive disorder (MDD). Although the etiology of the MDD has not been clarified yet, some studies suggest that hippocampus and the caudate nucleus play effective roles. In this study postmortem left hippocampus and caudate nucleus were collected from suicide victims with untreated MDD (n=7) and psychiatrically normal controls (n=6). The hippocampi and the caudate nuclei were stained with Vitamin D receptor (VDR) and glial fibrillary acidic protein (GFAP) antibodies. The hippocampi were stained with Ki67 antibodies. There were no significant differences between suicide and the control groups in the number of Ki 67 positive cells in the anterior and posterior dentate gyrus (DG) (p>0,05). There was a negative correlation between the number of Ki67 positive cells and age in the suicide in the anterior DG. The area fraction of GFAP immunoreactivity was not significant between groups in the anterior, posterior DG and caudat nucleus (p>0,05). In the anterior DG, but not posterior DG, the granular cell percentage with VDR immunoreactivity was significantly higher compared to that of the control group (p<0,05). The neuronal positivity for the VDR immunoreactivity was not significantly different between the two groups in the caudate nucleus (p>0,05). As a result, it was concluded that the immunohistochemical alterations in the anterior hippocampus were higher in the suicide victims with untreated MDD and there was an increase in the VDR in the granular cells as a protective factor. Key words: Hippocampus, vitamin d receptor, caudate nucleus