Paraventricular Thalamus Neuronal Ensembles Encode Early-life Adversity and Mediate the Consequent Sex-dependent Disruptions of Adult Reward Behaviors

While links between early-life adversity (ELA) and mental illnesses characterized by dysregulated reward behaviors are well-established, the underlying mechanisms remain unclear. In mice, ELA reduces hedonic consumption and interest in sex reward in adult males and, in contrast, augments reward consumption in females. Here, using genetic tagging (TRAPing) we found robust, sex-specific activation of thalamic paraventricular nucleus (PVT) neurons during ELA. Manipulating these neurons in adults normalized reward behaviors: Blocking TRAPed anterior PVT neurons restored hedonic consumption in ELA males and augmented hedonic consumption in control females. In contrast, activation of these neurons reduced consumption in control males and ELA females. For posterior PVT, blocking TRAPed cells attenuated excessive reward consumption in ELA females and reduced it in control males. Thus, PVT is key for adaptive brain plasticity; anterior and posterior PVT carry different functions and contribute to the effects of ELA on adult reward behaviors in a sex-dependent manner.