Oxytocin: The Neurotransmitter That Will Replace Friends?

The last decennia, it has become clear that oxytocin is an important neurotransmitter for also social behaviour. It is synthesized in the PVN by magnocellular and parvocellular neurons and has different projections throughout the entire brain. It plays a role in parental and sexual behaviour, social memory and recognition, and social bonding and affiliation. Intranasal administering of oxytocin results in an elevation of the mentioned social behaviours and it is suggested that this is due to a rise of central oxytocin level, although it is not clear yet how a nasal spray can influence the central levels. Furthermore, social support attenuates the stress response and so also the HPA-axis. It has been clearly shown that oxytocin levels are lowered in several sociopsychopathologies, like SAD, schizophrenia and autism. Intranasal administration of oxytocin reduces the social deficits in these diseases. On the other hand, social environment can also enhance the central oxytocin levels. From animal studies it can be deduced that both affiliation and isolation enhance the central oxytocin levels. This is also reproduced in humans, although these studies measured peripheral oxytocin levels. On the other hand, the behavioural effects of affiliation and isolation are the opposite of each other; the overall well-being is elevated during social support and reduced during isolation. Taking this into account, the medical profession might focus more on the self activating part of the oxytocinergic system instead of adding oxytocin.