Proceedings of The Physiological Society
King's College London (2011) Proc Physiol Soc 22, PC27
The effects of oxytocin on hippocampal neurogenesis
K. Musaelyan1, C. Anacker1, P. A. Zunszain1, C. M. Pariante1
1. IOP, KCL, London, United Kingdom.
The neurohypophysial hormone oxytocin, best known for its role in lactation and parturition, has been shown to play an important role in the central nervous system, modulating stress responses, pain perception, learning and different aspects of social behaviour, from trust to maternal care (Neumann, 2008). Animal and human studies showed that administration of oxytocin produces anxiolytic effects and decreases the release of stress hormones (Yoshida et al., 2009). The majority of studies of oxytocin levels in depression showed its negative correlation with depressive symptoms. It has been found that human hippocampal neurogenesis is involved in the pathogenesis of depression. It has been shown that depressed patients exhibit reduced levels of neurogenesis in hippocampal dentate gyrus, and antidepressants counteract this effect (Boldrini et al., 2009). Specifically, our laboratory has recently demonstrated that antidepressants exert their effect through the glucocorticoid receptor (Anacker et al., 2011). It has been shown that oxytocin in vivo has a suppressive effect on glucocorticoid receptor expression in the hippocampus (Petersson and Uvnäs-Moberg, 2003). Considering that, we hypothesised that oxytocin may have an antidepressant-like effect on hippocampal neurogenesis, which would strengthen the notion of its therapeutic potential for stress-related disorders, including depression. We used a human neural stem cell line HPC03A/07 (provided by ReNeuron Ltd., Surrey, UK) as an in vitro model of hippocampal neurogenesis. We assessed the effect of oxytocin treatment on cell proliferation by BrdU immunocytochemistry. The results showed that oxytocin has a stimulating effect on the proliferation of neural progenitors (20.13% increase upon 1μM oxytocin, p<0.05, t-test, n=3, and 20,51% increase upon 100nM oxytocin, p<0.05,t-test, n=3). These findings show that oxytocin has a positive effect on adult hippocampal neurogenesis, a process which is altered in depressed patients and proposed to be an alternative target of antidepressant treatment, therefore confirming the therapeutic potential of neurohormone oxytocin for depressive disorders.
Where applicable, experiments conform with Society ethical requirements