The research identifies a specific neural pathway, extending from the posterior amygdala (PA) to the ventromedial hypothalamus (VMHvl), as the primary driver of maternal aggression in female mice. During lactation, this circuit undergoes significant synaptic and cellular plasticity, making the aggression-related neurons more excitable than in non-maternal states. The study demonstrates that oxytocin acts as a crucial modulator, boosting the activity of this pathway to ensure mothers vigorously protect their offspring from potential threats. When pups are removed, a corresponding drop in oxytocin levels leads to a rapid decline in defensive behavior. Conversely, restoring oxytocin levels or using optogenetic stimulation can reactivate this aggressive drive. These findings ultimately reveal how hormonal changes and sensory cues work together to reorganize the brain’s circuitry for essential survival behaviors.

References:

• Yamaguchi T, Yan R, Khan M, et al. The neural mechanisms supporting the rise and fall of maternal aggression[J]. Nature, 2026: 1-11.