NOS1 and drug dependence: It is known that both glutamate and NO signaling play an important role in the development of drug dependence, since blockage of the NMDA receptor complex or administration of NOS inhibitors attenuated opioid (Gabra et al. 2005; Trujillo and Akil 1991; Vaupel et al. 1997), ethanol (Liljequist 1991; Uzbay et al. 1997), and nicotine (Jain et al. 2008a, b) withdrawal signs in animal models.