Evaluation of neurobehavioral characteristics in actively lactating and nonlactating Wistar rats

Abstract

Background : The processes of reproduction place a huge responsibility on the brain, hence the behavioral modulations observed in both the mother and the pups during this process owing to hormonal activities. Among such hormones are prolactin and oxytocin, which are majorly elaborated during lactation from the anterior pituitary and the hypothalamic nuclei. Recent in vivo data have implicated the receptors for these hormones in certain brain areas concerned with behavioral modulation. Aim : This study was therefore carried out to support existing documentation on the role of prolactin and oxytocin in neurobehavioral modulation. Materials and Methods : A total of 20 female Wistar rats were used for the study, 10 actively lactating and 10 nonpregnant, nonlactating. Neurobehavioral characteristics were evaluated in both groups using Open field and Hole-board tests. Results : In the Open field test, the result showed a significant ( P P Discussion : Increased locomotor and exploratory behaviors exhibited by lactating animals is an indication of fearlessness and reduced anxiety while reduced locomotor and exploratory behaviors in nonlactating rats indicated fear and higher level of anxiety also lactating animals exhibited high level of head-dipping, which was indicative of low anxiety-like state while the nonlactating animals exhibited reduced head-dipping which was indicative of high anxiety-like state. Conclusion: The authors therefore suggest that, the behavioral deficit observed in nonlactating, nonpregnant group could be due to the reduced plasma concentration of hormones responsible for the process of lactation (prolactin and oxytocin).