Physical sensations, such as a stomach knot when experiencing anxiety or trembling in the face of fear, have long been associated with our emotions. However, discerning the relationship between emotions and bodily functions has proven difficult due to the challenges in independently controlling the brain or body. Here we propose to develop biohybrid technologies that seamlessly integrate genetic tools, materials, and bioelectronic devices to enable minimally invasive manipulation of organ function. By enabling optogenetic control over the heart and peripheral nervous system, we will elucidate the pathways through which cardiac signals are transmitted to the brain to influence behavior and emotional states. Our findings will provide novel insights into the circuit mechanisms that underly the relationship between bodily feedback and emotions, and potentially pave the way for innovative therapeutic approaches in bioelectronic medicine.