Electrophysiological study of reticulo-limbic interrelationships during prolonged action of vibration

Phasic changes in the bioelectrical activity of the dorsal hippocampus (field CA3), the mesencephalic reticular formation, and several regions of the neocortex and the reticulo-cortical evoked potentials were measured under conditions of the action of prolonged vibration (3 months) in electrophysiological experiments with rabbits. Daily three-hour vibration during the first month of the experiment evoked an activation reaction in the EEG, characterized by a desynchronization effect in the neocortex and hippocampus and by the stabilization of the v rhythm in the mesencephalic reticular formation. Noted against this background was a certain facilitation in the reticulo-cortical evoked potentials, more pronounced in the neocortex, and a decline in the ascending activational influence of the mesencephalic reticular formation. The three-month action of vibration exerted an inhibitory influence on reticulo-cortical interrelationships, expressed in a decline in the compound bioelectrical activity of the cortex and subcortical formations, the excitability of the mesencephalic reticular formation, and the suppression of reticulo-cortical evoked potentials. At the same time an elongation of the latent periods of the positive phases of the evoked potentials, a decline in their amplitude, and a reduction of the negative phase in limbic structures was noted. The question of the physiological mechanism of development of vibrational pathology is discussed.