When a TRP goes bad: transient receptor potential channels in addiction.

Drug addiction is a psychiatric disease state, wherein a drug is impulsively and compulsively self-administered despite negative consequences. This repeated administration results in permanent changes to nervous system physiology and architecture. The molecular pathways affected by addictive drugs are complex and inter-dependent on each other. Recently, various new proteins and protein families have been discovered to play a role in drug abuse. Emerging players in this phenomenon include TRP (Transient Receptor Potential) family channels, which are primarily known to function in sensory systems. Several TRP family channels identified in both vertebrates and invertebrates are involved in psychostimulant-induced plasticity, suggesting their involvement in drug dependence. This review summarizes various observations, both from studies in humans and other organisms, which support a role for these channels in the development of drug-related behaviors.