AN EXPERIMENTAL-STUDY OF SPINAL-CORD EVOKED-POTENTIAL

The characteristics of spinal cord-evoked potentials were investigated by using an in vitro spinal cord preparation. The spinal cord isolate d from adult rats was immersed in a bathing chamber filled with oxygen ated artificial cerebrospinal fluid (aCSF). The spinal cord-evoked pot entials elicited by the stimulation of the spinal cord were recorded b y using bipolar platinum electrodes. The potentials recorded consisted of early and late negative components (N1, N2). The inhibitory effect of lowered temperature on the N1 potential was clearly demonstrated. The oxygen deprivation of aCSF showed the higher sensitivity of N2 pot ential to hypoxia than that of N1. It was also possible to analyze the effects of potassium and magnesium ion concentration and pH on the ev oked potentials. These results showed that the pure effects of various physiological and chemical factors on the spinal cord-evoked potentia ls can be analyzed by this experimental model.