[Role of monoamines in the recovery of the conditioned reflex activity of rats following extirpation of the frontal cortex].

The influence of frontal cortex extirpation on the amount of monoamines in the brain structures was investigated in chronic experiments on rats trained according to the method of motor feeding reflexes with bilateral reinforcement. Monoamine levels were measured by high performance liquid chromatography with electrochemical detection. By the ninth day after the ablation serotonin (5-HT) and dopamine (DA) levels were significantly reduced in the cortex and the striatum, respectively, while noradrenaline ++ (NA), 5-HT, dihydroxyphenylacetic and 5-hydroxyindoleacetic acid levels in raphe nuclei and locus coeruleus were increased. The level of conditioned reflex reproduction was 39% on the light and 33% on the sound stimulus. The involvement of monoamines in the recovery of conditioned reflexes after frontal cortex extirpation is discussed.