Metabotropic glutamate mGlu(1) receptor mRNA expression in dorsal root ganglia of rats after peripheral nerve injury

Although cerebral and spinal metabotropic glutamate mGlu(1) receptors are t hought to be involved in nociception and in the development/ maintenance of chronic pain, it is still unclear to what extent mGlu(1) receptors are pre sent in the dorsal root ganglia of peripheral sensory afferents, and whethe r their expression is affected during development of chronic pain. It was f ound in the present study that mGlu(1) receptor messenger RNA (mRNA) is pre sent in rat L5 dorsal root ganglia and that it is strongly downregulated af ter unilateral axotomy of the tibial branch of the sciatic nerve, a model o f chronic neuropathic pain. However, as sham-operated animals showed a simi lar downregulation, it is suggested that peripheral tissue damage is suffic ient to result in a reduction of peripheral mGlu(1) receptor expression. (C ) 2001 Elsevier Science B.V. All rights reserved.