Influência da estimulação tátil neonatal associada à administração de antidepressivo, sobre parâmetros comportamentais e bioquímicos em ratos jovens

Abstract

Early life events, in both humans and animals, may influence on brain development, leading to long-term consequences on adult behavior. Thus, this study was carried out in order to assess the influence of neonatal tactile stimulation (TS), when associated to sub-therapeutic administration of sertraline (SERT) in rats, on behavioral parameters related to depression-like. We also evaluated the influence of the TS-SERT association on the hypothalamic-pituitary-adrenal axis, as well as on the development of anxiety-like symptoms, assessed in different behavioral. Male rat pups were daily submitted to 10 min TS, from postnatal day (PND) 8 to PND 14. On DPN50, rats were first exposed to forced swimming test (FST). Then, after 24h, it was conducted the SERT administration and, 30 minutes later, animals were submitted to new evaluation on FST. On DPN51, rats were evaluated on the elevated plus maze (EPM). The animals were euthanized 24h after the behavioral tasks, followed by biochemical assessments. TS per se decreased depression behaviors, since there was an increase on swimming time and a decrease on immobility time in FST. On the EPM task, TS diminished behaviors related to anxiety, as shown in the increase of time on open arms and decrease on anxiety rates. In addition, TS also decreased corticosterone and cortisol plasma levels. All these results were enhanced when TS was associated to a sub-therapeutic dose of SERT. From these results, we suggest that neonatal handling TS may accomplish beneficial influence on parameters of depression, promoting the ability to cope with stressful situations in adulthood.