Social Touch Suppresses Aggression via Thalamic Mechanisms

Understanding the neural circuitry underlying aggression is critical for both scientific insight and clinical intervention. Here, we identify the posterior intralaminar thalamic nucleus (PIL) as a key node in an anti-aggressive circuit activated by social touch. Using a rodent model, we demonstrate that deprivation of direct physical contact during social isolation leads to heightened aggression. Chemogenetic and optogenetic manipulations reveal that PIL neurons activated by social touch inhibit aggression via excitatory projections to the medial preoptic area (MPOA) of the hypothalamus. This PIL-to-MPOA pathway is suppressed by input from the ventromedial hypothalamic nucleus (VMH). Our findings establish a novel thalamic-hypothalamic circuit that mediates social touch-induced suppression of aggression, offering potential targets for therapeutic intervention in conditions marked by pathological aggression.