DNA, RNA and cellular proteins are of great importance in regard to the following processes: learning, memorizing and storage of memory. That is why protein synthesis blockers are successfully used in investigations of these brain functions. Aktinomicin D (AMD) is such a substance; it is an antibiotic which is used in treatment of some malignant diseases, but on cellular level it disturbs RNA synthesis. Experiments were carried out on Chinchilla rabbits with chronically implanted electrodes for registration of electroencephalographic activity. Intracerebroventricularly applicated Aktinomicin D disturbs the appearance of habituation after rhythmic repetition of electrocutaneous stimulation of the same characteristics which clearly points to the importance of preserved cellular protein synthesis in the processes of learning.