Early maternal separation influence on Glucocorticoid Receptors in adult rats under Chronic Stress and Amitriptyline treatment

COTELLA, EVELIN M.; DURANDO, PATRICIA E.; SUÁREZ, MARTA M.

Florencia

Congreso; IBRO Congress; 2011

International Brain Research Organization (IBRO)

Early environment has many long-term effects on animals. It may affect the regulation the HPA axis during adulthood leading to a differential glucocorticoid secretion in response to stressful situations. Two types of nuclear receptors for corticosteroids were identified: mineralocorticoid receptors (MR) and glucocorticoid receptor (GR). MR?s prevail in limbic brain areas and bind corticosteroids with high affinity, while the lower affinity GR?s are widely distributed in neurons and glial cells. These receptors mediate in a coordinate manner the steroid control of HPA activity and behavior. The signaling through GR and MR has an important role in the interaction between limbic system and HPA axis. It?s been proposed that alteration in the balance between the expression and functioning of these receptors would be an important factor in the pathogenesis of stress related disorders. The aim of this work was to measure the immunoreactivity of GR in Hippocampus of adult Wistar Rats submitted to chronic variable stress (CVS) during 24 days. CVS consists in 5 stressors, with different intensity, which are presented randomly in time and order to the animals during the experiment. During the stress protocol, the animals were treated with antidepressant Amitriptyline (10 mg/KG). These rats had been previously exposed to 4.5 h of maternal separation during the first 3 weeks of life. In accordance to previous findings, an increase in GR inmunoreactive cells was seen in CA1 and CA3 regions in animals subjected both to separation and stress (p