Activation of the nucleus accumbens promotes place preference and counteracts stress-induced hyperthermia.

Positive affect promotes mental health and physical well-being, which may involve modifications in the autonomic nervous system activity. Here, we examine, using chemogenetic techniques, the effects of nucleus accumbens (NAc) activation on affect and body temperature regulation as a proxy of autonomic function. A conditioned place preference test revealed that nucleus accumbens activation induced positive affect. Chemogenetic and natural activations inhibited intruder stress-induced hyperthermia and prostaglandin E-induced fever. Chemogenetic inhibition did not show a negative affect but canceled the positive affect induced by the natural stimulus of chocolate or sucrose. Counting of c-Fos expression confirmed chemogenetic and sucrose-induced activation of the NAc. Our findings indicate that nucleus accumbens activation modifies a component of autonomic nervous activity and that this mechanism may underscore the link between positive affect and physical well-being. Applying our observations to humans may reduce fever side reactions of vaccines by employing preventive treatments that induce positive affect.