[A comparative analysis of the functional stability (based on electrophysiological criteria) of slices of the suslik and guinea pig brains maintained under deep hypothermia].

The effect of prolonged deep cooling has been investigated in hippocampal and septal slices from the brain of hibernating and active ground squirrels, as well as of the guinea pigs. The slices were kept at low temperatures (2-4 degrees C) for various periods of time (from several hours to 6 days) and were periodically tested in a warm (31 degrees C) incubation medium. Hippocampal field potentials (mainly of the field CA1) and spontaneous activity of single neurones of the medial septum were recorded. Significant differences were observed in the recovery of functional activity of the slices after their preparation as well as after cooling between experimental groups of animals. Slices from hibernating ground squirrels retained their activity for 7-9 days, those from active ones--for 6-7 days, whereas slices from guinea pigs did not recover their functional activity after cooling for more than 1-2 days.