[Statistical analysis of diencephalic neuronal spike activity during immobilization emotional stress in the rat].

On the basis of one second frequency values of spike activity, a study was made of statistical parameters of impulse flow power of 64 dorsomedial thalamus (DMT) neurones, 180 ventromedial thalamus (VMT) neurones and 110 ventromedial hypothalamus (VMH) neurones in alert rats during a 30 hour immobilization. The VMH neurones had highly significant lower values of standard deviations and variation coefficients of spike activity frequencies as compared with medial thalamic neurones. In the two parts of the medial thalamus (DMT and VMT) the neuronal mean frequency and standard deviations of spike activity frequencies were significantly enhanced at the initial stage of the animals' immobilization as compared with the final stage. In the VMH neurones enhancement of the mean frequency without pronounced change of other parameters of impulse was observed at the final stage of immobilization due to the appearance of a group of high frequency neurones with low variability of the spike flow.