The purpose of this work was an estimation of levetiracetam effects on reinforcing properties of self-stimulation of the lateral hypothalamus in rats as compared to the reference drugs lithium chloride and valproic acid in amphetamine-induced amplification reaction of self-stimulation in rats.
Materials and methods. To form a model of the brain self-stimulation bilaterally in the lateral hypothalamic nucleus implanted nichrome monopolar electrodes, followed by morphological control, and 7–10 days after the operation, the rats were trained to press a pedal for electrical stimulation of the brain. The effects of self-stimulation was assessed by analyzing the frequency of pedal and the threshold of self-stimulation. Study of the effects of test compounds started when the value of the average threshold of self-stimulation varied by less than 10% for three consecutive sessions of the brain self-stimulation. It is discovered the levetiracetam dose-dependently increases the threshold and reduces the maximum frequency of reactions of self-stimulation, suggesting that its inhibitory effect on the reward system, which is similar to the action of lithium chloride and different from actions of valproic acid. It is also shown potentiation of levetiracetam inhibitory effects in combination with valproic acid on amphetamine-induced reaction of self-stimulation in the rat, which is possible due to their effects on dopamine-ergic system.
Results. The experimental data suggest that the levetiracetam has a strong influence on behavior, in particular the supporting system of the brain, which is similar to the action of lithium chloride and different from the effect of valproic acid.