[Electrophysiological analysis of functional state of spinal cord motoneurons in rats with parathyroprivous tetany].

In normal rats and of those with parathyroprivous (hypocalcemic) tetany the comparative analysis of background activity (BA), tetanic and posttetanic increase and decrease of frequency of spinal cord (SC) motoneurons (MNs) responses under high-frequency (50, 100Hz) stimulation (HFS) of flexor (G) and extensor (P) hind-limb nerves have been conducted. The on-line selection and program analysis of the spikes was produced. On the 3-7 and 21-22 days of development of acute and chronic tetany, respectively, the significant tetanic and posttetanic changes of MNs activity without meaningful changes in BA was registered. Along with the abrupt increase of excitatory manifestation of activity to HFS in a period of development of acute tetany was observed their relative weakening in animals with chronic tetany. Simultaneously the weakening or total disappearance of depressor reaction, especially expressed in the period of development of acute tetany was noted. It was concluded on the causal dependence of the parathyroprivous convulsions due to disturbances of correlation of inhibitory-excitatory processes in SC MNs.