Developmental effects of oxytocin on GABAergic neurons in the olfactory brain regions

Abstract

Oxytocin affects social recognition, interactions, and behavior in adults. Despite growing data on the role of oxytocin in the sensory systems, its effects on early olfactory system development remain poorly understood. The present study aimed to investigate the developmental impact of oxytocin on selected parameters of the GABAergic system in olfactory brain regions. We found a significant increase in the expression of GABAergic markers and scaffolding proteins in the olfactory bulb during the early stages of development in both male and female rats, regardless of oxytocin treatment administered on postnatal days 2 and 3 (P2 and P3, 5 µg/pup). Oxytocin administration markedly reduced the expression of the scaffolding protein Gephyrin in male rats and it led to a significant increase in the number of GABAergic synaptic puncta in the piriform cortex of male rats at P5, P7, and P9. Our data suggest that the developmental action of oxytocin in relation to the GABAergic system may represent a mechanism by which the plasticity and maturation of olfactory brain regions are regulated.

Keywords: Brain development; GABAergic markers; Inhibitory synapse; Neurite arborization; Olfactory bulb; Oxytocin.