The effect of chronic social defeat on the expression of Arc, BDNF, Shank1b, Homer1A and VGLUT1 genes

The chronic social defeat model of depression is an ethologically based model of depression, in which a rat (the intruder) is defeated by a bigger, more dominant rat (the resident) for one hour per day during 10 consecutive days. At the end of the procedure, the defeated animal displays symptoms of a depressive-like behaviour including decreased sucrose consumption, increased plasma levels of corticosterone, loss of weight, increased adrenal weight and a blunted circadian rhythm in body temperature. We study the expression of genes involved in synaptic plasticity such as Arc, BDNF, Shank1B, Homer1A and VGLUT1 in the defeated animals and show a decrease in BDNF abundance in the ventral hippocampus, as well as reduced Arc and vGluT1 mRNA across cortical regions. The abundance of mRNA encoding Shank1B is also decreased in cortical regions.

VGLUT1mRNA expression in the hippocampus was determined by in situ hybridisation and quantified by optical density VGLUT1 mRNA after chronic social  defeat