Adult cell proliferation in the dentate gyrus.maternal separation metters? Results from a rat depression model

MIR F; RIVAROLA M A; POLLANO A; BARCENA B, SUÁREZ M, RIVAROLA MA, LEVIN G; AGUGGIA J

Mar del Plata

Congreso; Reunión anual Conjunta SAIC SAFE SAB SAP; 2019

Depression is one of the most common and debilitating mental disorders; however, its etiology remains unclear. Some possible pathophysiological mechanisms include altered neurotransmission, HPA axis abnormalities involved in chronic stress, reduced neuroplasticity, and network dysfunction. Neonatal maternal separation induces long-term alterations in the morphology of hippocampus and may increase vulnerability to depression when a stressful situation occurs in adulthood. Treatment with the antidepressant tianeptine may reverse the stress-induced alterations in neuroplasticity. The aim of our study was to investigate if the interaction between neonatal maternal separation and chronic unpredictable stress in adulthood can alter cell proliferation in the dentate gyrus. Also, we wanted to assess if antidepressant tianeptine could correct the alterations induced by our model.Also, the effect of the antidepressant tianeptine in the alterations induced by the present model was assessed.Wistar derived male rats were separated from their mother for 4.5 hr during the first 3 weeks of life. From day postnatal 50, were exposed to an unpredictable chronic stress paradigm during 24 days and were daily treated with tianeptine (10 mg/kg i.p.) or vehicle. Cell proliferation was evaluated by bromodeoxyuridine (BrdU) immunohistochemistry in the subgranular stratum of dentate gyrus.Maternally-separated rats showed a decrease in cell proliferation (p