[GABA(B) receptors and sensitization to pain]

The GABA(B) receptors belong to the family of class C metabotropic receptors. They are inhibitory receptors forming obligatory heterodimers. Their analgesic role in the dorsal horn of the spinal cord is well established since more than 25 years ago. However, Baclofen, the reference agonist of the GABA(B) receptor, proved to have little efficiency in clinics in neuropathic patients. It seems therefore useful to decipher GABA(B) functions in the nociceptive circuitry, and their regulation in conditions of chronic pain. In the present review, we will focus first on the distribution of the GABA(B) subtypes. Then, we will consider their pre- and post-synaptic functions in the dorsal horn of naïve rats. Finally, we will document the mechanisms that may lead to receptor impairment in neuropathic conditions.