Effect of handling by human being neonatal period on anxiety and Depression-like behavior of adult rats

Abstract

Human-animal interactions occur in many sectors of livestock production. This study aims to determine whether human manipulation during the critical period could disrupt their long-term behavior. Forty-four pup rats (22 males and 22 females), were divided into two groups (handling, non-handling: corresponding to the control group). Subsequently, each group was subdivided into two subgroups: male subgroup (Handling Males, H♂) and a female subgroup (Handling Female, H♀), which were handled daily for 5 min from birth to weaning. On postnatal days (PND 67,70,73), they were subjected to three behavioral tests respectively: open field (OF), elevated plus-maze (EPM) and forced swim test (FST). Within the open field, the results showed that in both sexes, the manipulated group had spent less time in corners, more time in the center, had more squares crossed and finally, more rearing. The results also showed significantly lower levels of anxiety, which translates into more time spent in open arms of the elevated plus-maze. Improved adaptation to depression was observed in forced swimming tests as they had more swimming time and less immobility time. Therefore, human handling during the neonatal period of rats could induce greater resistance to depression and better adaptation to anxiety without any negative effects on behavior.