Nonlinear pharmacological modulation of conditioning in the neocortex.

The conditioned defence reflex was elaborated by pair combination of direct stimulation of the motor cortex and electrocutaneous stimulation in awake nonimmobilized rabbit. This conditioning was organized mainly in the cortical part close to the stimulating electrode in the cortex. Influence of modulation of functional state on the observed phenomenon by means of application of GABA solution on the hypothetical place of the formation of the conditioning was examined. S-shaped dependence of effects on concentration of GABA solution was found. The hypothesis of the simultaneous modulation of processes of excitement and inhibition was used to analyse empirical dependences. Saturation effects (100% appearance of same alterations) were took into account. The model was suitable for description of the discovered nonlinear pharmacological modulation of physiological processes.