Kappa-opioid receptor activation reinstates nicotine self-administration in mice

Voluntary drug administration is a key facet of substance use disorder (SUD). Among the substances included under SUD, nicotine is the leading cause of preventable death. Nicotine use is also particularly sensitive to relapse, with stress being the major cause. Intravenous self-administration of nicotine has been the gold standard for accurately modeling SUD in rat and non-human primate models. However, this has been hard to achieve in mice. Here, using previously published protocols, we show that mice develop and maintain intravenous self-administration for nicotine and cocaine. Furthermore, we demonstrate that dynorphin-Kappa opioid receptor signaling, previously established to be necessary for negative affective behavior associated with stress, is sufficient to reinstate nicotine seeking in mice. With a stable model for volitional nicotine-seeking, we will be able to uncover the circuit- and molecular-level adaptations during the development, maintenance, withdrawal and relapse to pathological nicotine use.