Brain Oxytocin: A Key Regulator of Emotional and Social Behaviours in Both Females and Males

Abstract

The neuropeptide oxytocin (OXT) is currently attracting considerable attention as a result of the discovery of the amazing behavioural functions it regulates, especially in the context of social interactions. A broad variety of behaviours, including maternal care and aggression, pair bonding, sexual behaviour, and social memory and support, as well as anxiety-related behaviour and stress coping, are modulated by brain OXT. These discoveries make this neuromodulator ⁄ neurotransmitter system of the brain a promising target for psychotherapeutic intervention and treatment of numerous psychiatric illnesses, for example, anxiety disorders, social phobia, autism and postpartum depression.Together with the related nonapeptide arginine vasopressin (AVP), OXT is an essential part of the hypothalamo-neurohypophysial system. Since the original description of this system in fish by the German biologist Ernst Scharrer in 1928 (1), this welldefined arrangement of magnocellular neurones at the base of the brain has been one of the most valuable model systems in neuroendocrinology and neuroscience. Outstanding discoveries have been made through studying the OXT and AVP systems. These include the very first characterisation of a neuropeptide by DuVigneaud and, independently, by Acher in the 1950s, important insights into the bursting pacemaker activity of neurosecretory neurones (2), the discovery of neuropeptidergic pathways within the brain (3), novel views of neuronal-glial interactive plasticity (4, 5), and the development of neuropeptide receptor antagonists (6). Furthermore, the OXT system served as a suitable model arrangement for discovering important molecular and cellular mechanisms of neuropeptide synthesis, precursor processing, and cellular trafficking (7,8), as well as the stimuli and neuronal mechanisms of intracerebral neuropeptide release within distinct brain regions (9-11). These important findings have, in parallel, raised the question of the behavioural consequences of local OXT release and subsequent OXT receptor-mediated actions within brain target regions (12, 13). Journal of NeuroendocrinologyCorrespondence to: Inga D. Neumann, Department of Behavioural and Molecular Neuroendocrinology, University of Regensburg, 93053 Regensburg, Germany (e-mail: inga.neumann@ biologie.uni-regensburg.de).In addition to various reproductive stimuli, the neuropeptide oxytocin (OXT) is released both from the neurohypophysial terminal into the blood stream and within distinct brain regions in response to stressful or social stimuli. Brain OXT receptor-mediated actions were shown to be significantly involved in the regulation of a variety of behaviours. Here, complementary methodological approaches are discussed which were utilised to reveal, for example, anxiolytic and anti-stress effects of OXT, both in females and in males, effects that were localised within the central amygdala and the hypothalamic paraventricular nucleus. Also, in male rats, activation of the brain OXT system is essential for the regulation of sexual be...

Oxytocin-induced elevation of ADP-ribosyl cyclase activity, cyclic ADP-riboseor Ca2+ concentrations is involved in autoregulation of oxytocin secretionin the hypothalamus and posterior pituitary in male mice

“…Oxytocin (OT), a peptide of the vasopressin and OT family, plays a critical role in social recognition and behavior in mammals from rodents to humans (Donaldson and Young, 2008;Neumann, 2008). This short polypeptide hormone is secreted dendritically from neurons in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) of the hypothalamus and spread to other areas of the brain (McGregor et al, 2008;Skuse and Gallgher, 2009).…”

Combining oxytocin administration and positive emotion inductions: Examining social perception and analytical performance

“…Thus, additional research examining the context-specific effects that OT administration may have for analytical thinking is needed. Indeed, it seems plausible that in some contexts OT administration could benefit analytical task performance, perhaps via anxiety-reducing mechanisms (see Churchland and Winkielman, 2012;Neumann, 2008;Uvnäs-Moberg, 1998) or an enhanced approach orientation (De Dreu et al, 2013;Kubzansky et al, 2012).…”

CD38 and its role in oxytocin secretion and social behavior

“…(Yamasue et al, 2009;Ebstein et al, 2009: Munesue et al, 2010MacDonald et al, 2011;Bartz et al, 2011). In rodents, OXT is highly involved in social interactions, social recognition, pair-bonding, and maternal behavior (Winslow and Insel, 2004;Insel and Fernald, 2004;Young and Wang, 2004;Young, 2007;Neumann, 2008;Donaldson and Young, 2008;Insel, 2010;Higashida et al, 2010). In addition, animal studies have shown that increased levels of OXT during the early postnatal period may affect behavior, and these effects may last into adulthood (Carter et al, 2009).…”