Postpartum adversity in rats creates a hypervigilant maternal state through selective salience-circuit recruitment

Maternal caregiving is a central regulator of infant stress physiology and socioemotional development, yet surprisingly little is known about how early-life adversity reshapes the maternal organism itself. Here, we asked how postpartum resource scarcity alters maternal caregiving and the neural circuits engaged during the dam's social behavior outside the nest. Using a limited bedding (LB) manipulation during PN8-12, a window that reliably induces fragmented caregiving, we found that dams remained highly present in the nest but exhibited degraded caregiving quality, including reduced efficient pup transport and increased rough handling. During a mild social challenge with an unfamiliar adult female, LB dams showed intact sociability but heightened locomotor arousal in a social context, accompanied by increased Fos activation in basolateral amygdala (BLA), paraventricular thalamus (PVT), and ventral hippocampus (vHPC). Brain-behavior correlations dissociated these functions: BLA Fos predicted arousal, vHPC Fos predicted exploratory strategies, and lateral habenula (LHb) Fos negatively predicted sociability bias. Network analyses revealed largely preserved global topology but selective reweighting toward lateral habenula (LHb)-centered organization, with LHb emerging as the only region showing increased node strength under LB. Together, these findings identify a hypervigilant maternal phenotype in conditions of resource scarcity, marked by degraded tactile caregiving, salience-biased neural recruitment, and LHb-centered network reorganization. This maternal state likely alters the early-life environment in ways that contribute to the intergenerational transmission of adversity.