NERVE INJURY ENHANCES RAT NEURONAL GLUTAMATE TRANSPORTER EXPRESSION -IDENTIFICATION BY DIFFERENTIAL DISPLAY PCR

An increase in neuronal glutamate transporter expression after nerve i njury was demonstrated by means of differential display PCR (DD-PCR) c oupled with in site hybridization. DD-PCR was carried out to compare d ifferences in expression of mRNAs between axotomized and normal hypogl ossal motoneurons in the rat. The expression of several gene fragments were found to be increased following nerve injury; the full length cD NA corresponding to one fragment was cloned by subsequent rat cDNA lib rary screening. The close homology of glutamate transporters with our rat cDNA led us to conclude that this clone corresponds to the rat neu ronal glutamate transporter (rat EAAC1). We speculate that the upregul ation of this glutamate uptake system may increase the resistance of t hese cells against neurotoxic glutamate accumulation during the proces s of nerve regeneration.