Previous studies have shown that nicotine treatment not only causes swelling and structural remodeling of mitochondria in cells of various tissues, including the brain (Jin and Roomans 1997; Maritz and Thomas 1994; Onal et al. 2004; Zimmerman and McGeachie 1987), but also regulates processes such as protein turnover (Katyare and Shallom 1988), enzyme activity (Barbieri et al. 1989; Galvin et al. 1988), and generation of ROS (Bhagwat et al. 1998; Soto-Otero et al. 2002). Here, we further demonstrate that the genes of each complex in the electron transfer system are modulated by chronic nicotine treatment. The consistent changes in the genes included in complexes I, III, IV, and V of the electron transport system in multiple brain regions indicate the importance of this system in the interaction of the CNS with nicotine.
