[Generators of pathologically enhanced excitation as determinant structures in the spinal cord]

Using tetanus toxin as a tool to disturb the inhibition, enhanced excitation generators were created in the anterior horns of lumbar segments of the left and right sides of albino rat spinal cord. The generators worked at different regimens: the "left-side" generator originating under conditions of a more prolonged toxin action, on being activated by trigger stimulation, produced first tonic and then intermittent activity or periodic spontaneous discharges; the "right-side" generator produced only tonic activity. After the inhibition of one of the generators by glycine the other continued working in its regimen. Activation of one of the generators was followed by inhibition of the effect of the other. In case of separate activation of one of the generators all pools of the spinal and supraspinal motor neurons reproduced the activity pattern of the generator working at that moment. Thus, the latter played the role of the hyperactive structure determining the system behaviour, i.e. the determinant. The evidence obtained is analyzed from the point of view of the general concept on the role of the determinant structures in the nervous system activity and the theory of generator mechanisms of the neuropathological syndromes characterized by the system hyperactivity.