Improvement of interhemispheric interaction by polyprenol and nootropic agents in a visual evoked potential model in rabbits

BACKGROUND: Interhemispheric interaction is a complex mechanism that integrates the left and right hemispheres into a cohesive system, enabling compensation for functional impairments in one hemisphere. Studies of visual evoked brain potentials (VEPs) provide objective data on the state of visual analyzers under various brain conditions. AIM: To investigate interhemispheric interactions in male rabbits using light flash-evoked visual potentials and to compare the effects of polyprenol (administered at doses of 2 and 10 mg/kg) with the nootropic agents piracetam and aminophenylbutyric acid. MATERIALS AND METHODS: The study included 25 male Chinchilla rabbits implanted with epidural silver chloride electrodes above the visual cortex. Visual evoked potentials in response to light flashes presented from different directions were recorded. Changes in the latency and amplitude of primary response components — negative oscillations at 75 ms (N75) and positive oscillations at 100 ms (P100) — were evaluated under the influence of polyprenol at doses of 2 and 10 mg/kg and compared with piracetam and aminophenylbutyric acid, which were administered intraperitoneally. RESULTS: Polyprenol, like the comparator drugs, improved brain information processing during light stimulation of both eyes by either reducing latency or increasing amplitude. A comparison of VEP responses recorded from the hemisphere opposite to the light stimulus revealed greater reactions in the right hemisphere during left eye stimulation than vice versa. CONCLUSIONS: Polyprenol at a dose of 2 mg/kg reduces response latency in VEPs during bilateral light stimulation, while a dose of 10 mg/kg increases amplitude. The interhemispheric interaction observed in rabbits is comparable to aminophenylbutyric acid and surpasses that of piracetam when polyprenol is administered at 2 mg/kg.