Effect of Perinatal Monosodium Glutamate Administration on Visual Evoked Potentials of Juvenile and Adult Rats

摘要

Administration of high doses of monosodium glutamate (MSG) to rats during the first postnatal week results in severe losses of retinal ganglion cells and interneurons in the retina. The study was conducted to determine what effect this severe retinal damage would have upon the ontogeny of rat flash evoked potentials (FEPs) and the adult pattern reversal evoked potentials(PREP). MSG (4 mg/g) or isotonic saline was administered to rat pups daily from postnatal day (PND) 2 until PND 9. FEPs were recorded following 2 stimulation frequencies from unanesthetized, unrestrained MSG treated and control rats on PND 15, PND 22, and PND 60 or older. PREPs were recorded from unanesthetized, restrained rats older than PND 60 from each treatment group. On PND 15, 9 of 12 control animals exhibited responses to light flashes, while only 4 of 12 MSG treated animals did so. All animals from both treatment groups exhibited FEPs on PND 22. All FEP peak latencies were significantly increased in MSG treated animals with the magnitude of the effect being greater during development. Perinatal MSG treatment results in profound alterations in FEP ontogeny and the generation of PREPs.