The effect of maternal deprivation on empaty-like behavior in rats

Aim: The aim of this study is to investigate the effect and possible mechanisms of maternal deprivation stress on empathy and anxiety-like behaviors and also difference between females and males, using behavioral tests, histological and biochemical methods in rats. Method: Thirty two female and male Sprague Dawley rats were used in this study. Half of the litters were separated from their mothers for 24 hours on postnatal 18th day and the other half was left with their mothers. The rats were caged in pairs at 4 weeks of age. All subjects were trained to rescue the stressed cage mate using the empathy test equipment for 12 days. The effect of naltrexone on empathy has also been evaluated. After empathy experiments, the anxiety levels of all rats were assessed using the open field test and the elevated plus maze test. Then subjects were sacrified, OXT and AVP levels in amygdala and PFC and receptor binding in hippocampus DG, CA1 and PFC were measured. Findings: Empathy behavior and anxiety levels weren't differ significantly between groups. Amygdala AVP level was increased in the maternal deprivated males compared to the male control group. In control groups, AVPR1a binding level was higher in CA1 and PFC. In DG, AVPR1a binding in the female experimental group was higher than the male experimental and female control groups. OTR binding in control groups in PFC and DG were higher. In CA1, OTR binding was higher in male controls. Result: It has been concluded that changes in OT and AVP systems in specific brain regions may play a role in the psychopathologies caused by early life adversities regardless of impairment of empathy and anxiety-related behavior.