Paraventricular thalamus gates hippocampal coding of salient experiences.

Abstract

Adaptive behavior requires neural circuits that encode salient stimuli to guide approach and avoidance. The hippocampal ventral subiculum (vSub) encodes information related to avoidance and reward seeking, yet how upstream inputs shape its representations of salient appetitive and aversive events remains unclear. Here, we show that a projection from the anterior paraventricular thalamus (PVT) to vSub carries an aversive-state signal that biases vSub representations toward threat-related information. In anxiety-provoking environments, anterior PVT to vSub activity is associated with avoidance behavior and enhanced vSub discrimination of threat and safety. During associative learning, this circuit preferentially promotes vSub responses to threat-predictive cues and aversive outcomes while constraining representations of rewarding stimuli. These findings refine canonical limbic circuit models by identifying a direct thalamic influence over hippocampal coding of rewarding versus aversive stimuli and the approach-avoidance behaviors they guide.