LTP pathway in the alcoholics, the phosphatidylinositol signaling system, which is closely related to the LTP pathway, was significantly altered by chronic exposure to both cocaine and alcohol. These findings of gene expression changes, together with other studies that have shown the effects of cocaine on LTP (del Olmo et al., 2006; Dunwiddie, Proctor, & Tyma, 1988; Guan, Zhang, Xu, & Li, 2009; Huang, Lin, & Hsu, 2007; Smith, Browning, & Dunwiddie, 1993; Thompson, Gosnell, & Wagner, 2002; Thompson, Swant, & Wagner, 2005), provide evidence that chronic exposure to cocaine, and possibly alcohol, leads to long-term changes in the plasticity of the hippocampus and underlines the importance in addiction of molecular mechanisms for learning.
