Mitochondrial uncoupling protein 2 in the central nervous system: neuromodulator and neuroprotector.

Uncoupling proteins (UCPs) are localized in the inner membrane of the mitochondria in diverse tissues and decrease mitochondrial membrane potential. The first of these proteins, UCP1, was discovered in brown adipose tissue, where it has a well-described role in thermogenesis. The functional significance of other UCPs, including UCP2, is less well understood. Here we summarize the recent advancements on the role of UCP2 in the brain and portray this uncoupler as an important player in normal neuronal function as well as a key cell death-suppressing device. These previously unknown functions of UCPs offer new avenues not only for the better understanding of these proteins but also for the furthering of our knowledge on the central nervous system in healthy and disease states.