beta 3, a novel auxiliary subunit for the voltage gated sodium channel is upregulated in sensory neurones following streptozocin induced diabetic neuropathy in rat

In the present study we have used in situ hybridization to examine the chan ges in mRNA expression of the voltage gated sodium channel subunits beta1 a nd beta3, which occur in response to streptozocin induced diabetic neuropat hy. Under control conditions beta1 mRNA was detected throughout the spinal cord and in large dorsal root ganglion (DRG) AP fibres whilst beta3 mRNA wa s expressed exclusively in the layers I/II and X of the spinal cord and in small DRG c-fibres. Following streptozocin treatment, the expression of bet a1 mRNA remained unchanged in both the spinal cord and DRG whilst beta3 mes sage was significantly increased in both the spinal cord and in medium diam eter A delta type DRG neurones. In conclusion, the present study illustrate s that the development of the neuropathic pain state is associated with dis tinct changes in the pattern of beta3 subunit expression and that these cha nges appear to be specific to the neuropathic pain state induced. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.