Abstract
Changes in the chloride homeostasis-related genes in trigeminal nuclei of the adult rats with nerve injuryBing Wei, Atsuo FukudaDepartment of Physiology, Hamamatsu University School of Medicine, Hamamtsu, Shizuoka 431-3192, JapanAbstractAccording the modern pain control theory predicts that a loss of inhibition in the dorsal horn of the spinal cord is a crucial substrate for chronic pain syndromes. It involves a trans-synaptic reduction in the expression of the potassium-chloride exporter KCC2. we have previously shown KCC2 mRNA downregulation in injured facial motoneurons, that impairs Cl¯ homeostasis and makes GABA act depolarizing. We report here changes in the expression level of the KCC2 and NKCC1 mRNAs in the trigeminal nuclei of an experimental rat model of trigeminal neuropathic pain produced by a chronic constriction injury to the infraorbital nerve. By means of in situ hybridization histochemistry, our data indicates that 1 to 3 weeks after the operation the KCC2 mRNA was downregulated in the spinal nucleus. The result suggests that the KCC2 downregulation may play pivotal roles in the trigeminal neuralgia by rendering GABA action depolarizing. [J Physiol Sci. 2006;56 Suppl:S213]
