Moreover, we have analysed by immunohistochemistry the expression of the immediate early gene c-Fos (c-Fos IR), an indirect marker of neural activity, after the administration of GAL(1-15)+ESC in OBX rats in several nuclei involved in MDD: Hippocampus, PFC, lateral (LHb) and medial (mHb) habenula. This evidence concerns the gene FOS and major depressive disorder.