Gene Arrays and Proteomics: A Primer

In recent years, molecular biology has increasingly focused on how cellular effectors are modulated by the environment and, in turn, modulate each other to control cellular functions. In the opioid field, we concern ourselves both with signaling mechanisms within cells and the functions of neural circuitry in mediating the behavioral effects of opioids. All of these mechanisms identified to date have proven to be extremely complex, suggesting that behavioral outcomes mediated by opioids are dependent on the interactions of multiple gene products. Opioid-mediated behavioral outcomes such as tolerance, dependence, and addiction may reflect problems in the regulation of complex biological and emotional functions. From this, it follows that slight alterations in the expression or function of individual genes that still fall within the “normal” range could lead to pathological effects or behaviors. Genetic polymorphisms cause changes in the coding and regulatory regions of genes. Thus, in addition to changes in levels of protein expression, encoded proteins may have slightly different functions or undergo differential regulation in cells.