Social Behaviour and Oxytocin Secretion in the Brain Regulated by CD38 in Human and Mice

Oxytocin (OXT) in the hypothalamus is the biological basis of social recognition, trust, love and bonding. Previously, we showed that Cd38, a proliferation marker in leukaemia cells, plays an important role in the hypothalamus in the process of OXT release in adult mice. Disruption of Cd38 (Cd38-/-) elicited impairment of maternal behaviour and male social recognition in adult mice (Nature, 446, 41, 2007), similar to the behaviour observed in Oxt and OXT receptor (Oxtr) gene knockout (Oxt-/and Oxtr-/-, respectively) mice. Impairment was also prominent in Cd38-/newborn mice. However, these behaviours were much milder than those observed in Oxt-/and Oxtr-/mice. These phenotypes seemed to be caused by the high plasma OXT levels during development from neonates to 3-week-old juvenile mice. These results suggest that secretion of OXT into the brain in a Cd38-dependent manner plays an important role in the development of social behaviour. Based on these results in animal experiments, OXT treatment for autistic subjects as a restore method has been proposed, and its use has begun in several hospitals. Key-words: Oxytocin, Social recognition, Maternal behaviour, CD38, Autism