Oxytocin-induced balance of cortical inhibition and excitation facilitates behavioural changes in pup retrieval by mice

Abstract

Across species, oxytocin (OT) has been identified as a neuromodulator of social interactions and maternal behaviour. The timing, location, and method of how oxytocin alters neural activity, however, are not well characterized. In order to elucidate oxytocin’s mechanism of action, Marlin et al. (2015) investigated differences in pup retrieval among maternal female mice (dams), naïve virgin mice, and experienced virgin mice, as well as the role of oxytocin in eliciting or modifying their behaviours. As muscimol inhibition of the left auditory cortex (AI) prevented pup retrieval, so systemic application of oxytocin accelerated maternal reactions to pup vocalizations. Neural responses to vocalizations confirmed lateralization of responses in the left AI of experienced adult mice. Further, Marlin et al. (2015) observed that current-clamp and cell-attached recordings of the left AI in dams and experienced virgins demonstrated precisely timed combinations of excitatory and inhibitory activity as a response to pup calls. Finally, optogenetic oxytocin stimulation paired with pup vocalizations resulted in the balancing of size and time of inhibition with excitation. These results indicate synaptic balance as the mechanism that allows oxytocin to enhance salience of socially relevant auditory information.