Maternal aggressive and protective behavior is linked to the hormone oxytocin (OT), and may affect the maternal instincts of animals and women in the same manner.
The hormone is released from the neurohypophyseal terminals into the bloodstream as well as in the brain into the supraoptic nucleus (SON) and paraventricular nucleus (PVN), where it makes and impact on the behavior. The release of hormone oxytocin in the brain can lead to auto regulation of oxytocin neuronal activity, promotion of maternal behavior and maternal aggression and morphological plasticity.
Drawing parallel from the mice study, the researchers from University of Edinburgh said that in highly anxiety prone animals, the release of the hormone directly influences the level of maternal offensive behavior against a perceived threat. This is more pronounced in lactating mothers than at any other species.
Researchers also say that other than increasing the maternal protective instincts during the lactating phase, the oxytocin hormone also regulates the functions of hypothalamic-pituitary-adrenal axis that controls the anxiety levels.
The researchers had started their investigations by directly inserting the oxytocin hormone in the brains of the virgin female rats and found out that the functions of the hormone receptor binding in the central amygdala reduces the levels of anxiety and promotes dominant social behavior in females.
Reference: American Physiological Society's 2005 Conference, July 2005