ELECTROPHYSIOLOGICAL RESPONSE OF THE RABBIT BRAIN TO CHRONIC HYPERNATREMIC DEHYDRATION AND REHYDRATION

In thirty-two rabbits epidural electrodes were placed and in ten of these animals concentric depth electrodes were placed stereotactically. All animals with both epidural and stereotactically placed electrode; were rehydrated with intravenous 2.5% dextrove in water over a four-hour period. Animals with just epidural electrodes had normal tonicity restored by intravenous 2.5% dextrose administered over six or eight hours or by the ad libitum oral intake of tap water. The electrical cortical activity was monitored at 15 minute intervals throughout rehydration and for an additional four-hour observation period. In animals rehydrated over a four-hour period seizures were most prominent during the third and fourth hour of rehydration and the first hour of the observation period. Slowing of the electrical actisity and development of spikes occurred during this same period of time in some animals without as well is some with clinical seizures.