Strychnine and microwave radiation produced changes in spectral parameters of electrocorticogram, correlation dimension, and Kolmogorov entropy, parameters calculated by the methods of nonlinear dynamics opposite to those induced by urethane. The modulatory effect of microwaves on bioelectric cerebral activity in narcotized animals was similar to the effect of strychnine and probably related to enhanced excitability of brain structures and complication of bioelectric processes.