Oxytocin shapes spontaneous activity patterns in the developing visual cortex by activating somatostatin interneurons

Summary Spontaneous network activity shapes emerging neuronal circuits during early brain development prior to sensory perception. However, how neuromodulation influences this activity is not fully understood. Here, we report that the neuromodulator oxytocin differentially shapes spontaneous activity patterns across sensory cortices. In vivo, oxytocin strongly decreased the frequency and pairwise correlations of spontaneous activity events in the primary visual cortex (V1), but it did not affect the frequency of spontaneous network events in the somatosensory cortex (S1). Patch-clamp recordings in slices and RNAscope showed that oxytocin affects S1 excitatory and inhibitory neurons similarly, whereas in V1, oxytocin targets only inhibitory neurons. Somatostatin-positive (SST+) interneurons expressed the oxytocin receptor and were activated by oxytocin in V1. Accordingly, pharmacogenetic silencing of V1 SST+ interneurons fully blocked oxytocin’s effect on inhibition in vitro as well its effect on spontaneous activity patterns in vivo. Thus, oxytocin decreases the excitatory/inhibitory (E/I) ratio by recruiting SST+ interneurons and modulates specific features of V1 spontaneous activity patterns that are crucial for the wiring and refining of developing sensory circuits.
Graphical Abstract
Highlights • Oxytocin modulates spontaneous activity event patterns in the developing V1 • Oxytocin increases inhibition by activating somatostatin+ interneurons • SST+ neuron activity reduces event frequency and correlations, but not amplitude • In S1, oxytocin increases excitation and inhibition and does not modulate frequency
Maldonado et al. uncover oxytocin’s role in developing sensory cortices. In vivo, they show that oxytocin decreases the frequency and correlations of spontaneous activity patterns in V1 by specifically activating somatostatin+ interneurons. In S1, oxytocin increases both excitation and inhibition and does not affect spontaneous activity frequency.