Mechanisms of the Pharmacological Modulation of Obsessive-Compulsive and Cognitive Disorders in Cats Recognized by the Method of Normalizing FFT-Convertible Functions of Electrograms of the Frontal Cortex and Hippocampus

The pharmacological modulation and analysis of psychopathological processes in animals is a research method providing a possibility to study similar processes in humans. Methods and approaches based on the principles of the pharmacological modulation of systemic behaviour and normalization of FFT-transformed functions of the brain electrograms allow identication of the quantitative parameters of intracentral relations, cognitive functions and fundamental mechanisms for evaluating the effects of neuropsychoactive drugs in the whole brain in vivo . The work was carried out on cats with stereotactically implanted electrodes in the brain. Subtherapeutic doses of ketamine, amphetamine and nakom were used to model obsessive-compulsive disorders and cognitive changes. The pharmacological modulation of the animals’ behaviour was evaluated by the effect on the frontal brain and hippocampus. The activation of γ-rhythms (from 35 to 60 Hz) was considered as an improvement in cognitive functions. Ketamine exhibited a more pronounced depressing effect on the proreal gyrus, with its activating effects being close to amphetamine across the frequency ranges of 11–15 and 32–35 Hz. Ketamine had a pronounced activating effect on the gyrus suprasilvium anterior and the hippocampus. Ketamin and nakom demonstrated similar effects in the area of the proreal gyrus, most clearly manifested at frequencies of about 9–15 and 35–36 Hz. The action of nakom was characterized by the episodes of activation in a higher frequency range of 40–55 Hz as well. In the area of the gyrus suprasilvium anterior, the effects of nakom were similar to those of ketamine; however, these substances exhibited different effects in the range of 9–11 Hz. Compared to amphetamine, nakom showed no depressing episodes over the high-frequency range of 55–65 Hz. In the hippocampus, nakom demonstrated an activating effect exceeding that of ketamine by 100–150%. It was shown that neuroimaging of the normalized functions of electrograms during the pharmacological modulation of obsessive-compulsive and cognitive disorders reects the most striking transformations in high-frequency brain rhythms, primarily related to the γ-range. Comparison of the results of pharmacomodulation with the pharmacodynamic and pharmacokinetic parameters of drugs when modelling psychopathologies in animals helps researchers in their search for approaches to modifying animal behaviour and extrapolating them to humans.