An important role in the mechanisms of action of the known nootropic drugs is ascribed to macromolecular synthesis . An increase in the intensity of uptake of labeled precursors into proteins of a cell suspension from certain parts of the brain has been demonstrated experimentally. In the modern view, long-term retention of the memory trace is connected with activation of protein synthesis in the region of synaptic boutons . Research workers are interested not least in the role of intracellular formations, notably structures of the endoplasmic reticulure, in the mechanism of integrative functions of the neuron. There is evidence that weakly bound microsomal surface proteins of animals exhibit reactivity during learning . The aim of this investigation was to study the effect of structural analogs of ethylnorantitheine (ethimizole), a substance with nootropic type of action, on protein metabolism in various intracellular structures of rat brain neurons.