Physiologic effects of maternal separation on rat brain neurochemistry: comparative study

ABSTRACT

Exposure to maternal separation in early life is associated with alteration in the neuroendocrine and neurotransmitter system which may be associated with risk of psychiatric disorders development at adulthood. The aim of this study was to [i] assess levels of monoamines [dopamine, nor-epinephrine, epinephrine and serotonin] in rat pup's brain following repeated maternal separation [RMS] and maternal deprivation [MD]. [ii] Assess brain corticosterone and oxytocin level following both RMS and MD. This study was carried out on 50 male rat pups divided into 3 experimental groups; Group I 20 rats subjected to 3 h of repeated maternal separation for 14 days; Group II 20 rats subjected to 24 h of maternal deprivation; Group III 10 rats served as control group. At the end of the experimental period, all rats were sacrificed and their brains were rapidly removed and dissected for estimation of monoamines, corticosterone and oxytocin. Brain corticosterone level showed marked increase after both separation procedures, however, MD was associated with marked increase. RMS was associated with higher level of epinephrine, norepinephrine, dopamine and serotonin. Dopamine and serotonin levels however, were reduced after MD. Oxytocin level showed marked reduction after MD and RMS. The current work provided some neurobiological evidence supporting the determinant role of mother-infant relationship in the development of psychopathology. Maternal separation leads to profound alterations in the central neurotransmitter system and therefore is associated with increased risk of psychiatric disorders as depression and anxiety. Moreover, maternal separation has impact on the corticosterone and oxytocin release in the brain. Different separation procedures however, can influence the consequences of MS