Gene expression changes in the human amygdalar sub-nuclei in major depressive disorder
Sharma V, Chaudhury S, Thompson RC, Myers RM, Schatzberg AF, Barchas JD, Bunney WE, Akil H, Watson SJ
Society for Neuroscience. 2013.
Amygdala is a sub-cortical nucleus in the telencephalon that plays a major role in regulating not only physiological or autonomic behaviors but also higher cognitive and affective functions such as attention, emotion, memory and decision-making. Due to its central role in mediating these brain functions, it is implicated in various psychiatric disorders including Major Depressive Disorder (MDD). It has been shown that the regional connections between different sub-nuclei may play a role in regulating and maintaining the pathophysiology. To date, there have been no studies undertaken to show the gene expression changes occurring in these individual sub-nuclei which may be relevant to the pathophysiology of MDD. In the present study we report the gene expression changes occurring in the individual sub-nuclei of amygdala in MDD patients. Human brain samples of 16 healthy control subjects and 26 MDD patients were obtained from the Brain Donor Program at the University of California, Irvine. The blocks containing the amygdala region were cryo-sectioned at 10µm thickness. The location and orientation of various sub-nuclei in these sections were identified using acetylcholinestrase staining. Various sub-nuclei were dissected by laser capture microscopy, RNA extracted and gene expression assessed using microarrays (Illumina). We will describe the differential expression patterns of gene expression in the individual sub-nuclei of the amygdala of MDD subjects relative to normal controls. The findings should help elucidate the specific role that each sub-nucleus may play in the pathophysiology of MDD.