Scientists have identified a neural circuit that allows mother mice to awaken selectively in response to their offspring's cries, revealing how motherhood changes the sleeping brain.
Published in Nature Neuroscience, the research investigated communication between the auditory system, cerebral cortex, and preoptic area of the hypothalamus.
The researchers identified neurons in layer six of the temporal association and ectorhinal cortices that transmit offspring-related auditory information to the preoptic area, a brain region involved in regulating sleep and arousal.
Following motherhood, these neurons became more responsive to pup calls, partly because of increased expression of dopamine D1 receptors.
A pathway connecting the auditory thalamus to these cortical neurons also maintained sensitivity to offspring vocalizations during sleep.
The discovery complements research into neural circuits that regulate sleep and broader investigations of how brain networks coordinate behavior.
Although the mechanism may reflect an evolutionary adaptation for caregiving, these experiments were conducted in mice, and comparable mechanisms in humans remain to be established.