Changes in the spontaneous and stimulus-evoked activity in the somatosensory cortex of rats on acute manganese administration

In this work, acute effects of inorganic manganese exposure on nervous electrical activity of rats were investigated. Young adult male Wistar rats were prepared for recording in anaesthesia and spontaneous cortical as well as stimulus-evoked cortical and peripheral nervous activity was recorded before and after i.p. administration of 25 and 50 mg/kg Mn2+. The alterations found resulted possibly from several known neuronal effects of manganese. The frequency shift of spontaneous cortical activity, and increased latency and decreased amplitude of the peripheral nerve action potential, were probably due to the Mn2+-induced impairment of the mitochondria, whereas the increased amplitude of the evoked cortical response, to the effect on glutamatergic transmission. (C) 2004 Elsevier Ireland Ltd. All rights reserved.