Biologists began investigating the neuronal changes underlying cocaine addiction many years ago. Some studies focused on what was happening on cell membranes; others tackled the less accessible molecular and genetic developments inside neurons. About five years ago, this intracellular approach largely petered out in the face of dauntingly complex biochemical pathways and proteins with unfathomable functions. A few labs persisted, however, and their explorations are starting to hit pay dirt. In March, for example, a team of 12 neuroscientists published a Nature paper detailing, for the first time, how chronic cocaine exposure affects several proteins along a critical signal transduction pathway in neurons.1
The ultimate goal of all this research is to tease out how short-term changes in intracellular proteins lead to the lifelong bodily changes that maintain addiction and cause relapse. One key protein identified in the Nature paper, cyclin-dependent kinase 5 (Cdk5), is "a very good candidate for ...
