A few studies have suggested a role for cell adhesion and extracellular matrix proteins in the response to cocaine. Disturbances in cortical cytoarchitecture in animal models of prenatal cocaine exposure resembled changes observed when Wnt/cadherin pathway function was altered; this lead to the prediction that these pathways play a role in the response to cocaine (Novikova et al., 2005). As observed here (Cluster i), Cdh6 and Cdh11 expression increased in the frontal cortex of E18 pups taken from dams treated with cocaine for 10 days (Novikova et al., 2005). Also contributing to alterations in the extracellular milieu is cocaine-mediated down-regulation of glycosyltransferase expression; these enzymes are crucial for the synthesis of cell surface glycoproteins. In a compilation documenting changes in gene expression in postmortem tissue from cocaine addicts, cell adhesion molecules were identified as major targets (Lehrmann et al., 2003; Mash et al., 2007).
