Shedding "UV" light on endogenous opioid dependence.

ABSTRACT

Excessive sun tanning can result in addictive behavior. In this issue of Cell, Fell et al. utilize a combination of behavioral pharmacology and transgenic mice to demonstrate that chronic UV light exposure recruits p53 signaling in keratinocytes, subsequently increasing ß-endorphin signaling at opioid receptors, and produces an endogenous opioid-dependent state.