[An experimental study on neurotoxicity of 2,5-hexanedione. Visual and somatosensory cortical evoked potentials in rats]

Abstract

In order to clarify the effects of 2,5-hexanedione (2,5-HD) on the central nervous system, the somatosensory evoked potentials (SEP) and the visual evoked potentials (VEP) were experimentally studied. Eight male rats (Jcl-Wistar) were given subcutaneously 300 mg/kg/day of 2,5-HD five days a week for three weeks. Another eight male rats group served as the control. One week after ending the administration, the SEP and VEP of rats were measured under artificial respiration using bipolar and monopolar recording methods. The caudal nerve conduction velocities (C-NCVs) were also measured before the administration was begun, and weekly during the experiment, using Ono's method. Significant findings observed in the 2,5-HD administered group in comparison with the control group were as follows: delayed latencies in P1 and N1 components of VEP, reduced amplitude between N1 and P2 components of VEP and decreased caudal nerve conduction velocities. It was also observed that latencies of SEP components of the 2,5-HD administered group tended to prolong in spite of shorter conducting length. Alterations of VEP and a tendency of prolongation in latencies of SEP components were considered to be dysfunctions of the visual and somatosensory afferent pathway attributable of 2,5-HD. The present experiments suggest that for further understanding of the effects of 2,5-HD, on the central nervous system, it is necessary to utilize more sophisticated techniques which can quantitatively detect neurophysiological changes in the ascending tract from the periphery to the cortex.