Oxytocin Shapes Spontaneous Activity Patterns in the Developing Visual Cortex by Activating Somatostatin Interneurons

Area of Science:

• Neuroscience
• Developmental Neuroscience
• Neurobiology

Background:

• Spontaneous network activity is crucial for developing neuronal circuits before sensory input.
• The influence of neuromodulators, like oxytocin, on this early activity is not well understood.

Purpose of the Study:

• To investigate how oxytocin differentially modulates spontaneous activity patterns in sensory cortices during early development.
• To elucidate the cellular mechanisms underlying oxytocin's effects in the visual and somatosensory cortices.

Main Methods:

• In vivo electrophysiology in rodent models.
• In vitro patch-clamp recordings in brain slices.
• RNAscope for gene expression analysis.
• Pharmacogenetic manipulation of specific neuronal populations.

Main Results:

• Oxytocin significantly reduced spontaneous activity frequency and correlations in the primary visual cortex (V1) but not the somatosensory cortex (S1).
• In V1, oxytocin selectively targeted somatostatin-positive (SST+) inhibitory interneurons, activating them via oxytocin receptors.
• In S1, oxytocin affected excitatory and inhibitory neurons similarly.
• Silencing V1 SST+ interneurons abolished oxytocin's effects on both inhibition and spontaneous activity in vivo.

Conclusions:

• Oxytocin decreases the excitatory/inhibitory (E/I) ratio in the developing V1 by recruiting SST+ interneurons.
• Oxytocin selectively modulates V1 spontaneous activity patterns, which are critical for sensory circuit refinement and wiring.
• These findings highlight a specific role for oxytocin in shaping early visual cortex development.