[Long-term studies of the reproducibility of evoked spinal potentials from chronically implanted recording electrodes in the rat].

Over a period of 4 weeks we examined the reliability of spinal cord nerve potentials in the thoracic-lumbar region after stimulation of the hindpaw in 10 rats. Recording electrodes were chronically implanted over a period of 4 weeks into the lower thoracic and upper lumbar lamina by using an operation microscope. The action potentials were recorded at the dorsal root entry zone after stimulating the hindpaw. By comparing the data of the recording sessions we found a high reliability of the spinal cord evoked response over a long period. The experimental model is appropriate for the assessment of neurophysiological changes in the long term. Additionally we examined some basic characteristics of the evoked spinal response in this area.