Effects of chlordiazepoxide on acquisition and performance of a go-no go successive discrimination task, and on brain biogenic amines in cats.

1. Normal and chlordiazepoxide (0.4 mg/kg/day, per os) treated cats were trained on a symmetric go-no go successive discrimination task with positive reinforcement. 2. The treatment impaired the acquisition, but not the performance once the task was learned. 3. Serotonin, 5-hydroxyindoleacetic acid and noradrenaline were assayed in 12 brain areas in trained cats, and in normal and treated cats which did not undergo the training. 4. The treatment produced localized changes in the serotonin: 5-hydroxyindoleacetic acid ratio and the noradrenaline level; these effects were modified by the training. 5. The drug induced an acquisition deficit rather than a general behavioral disinhibition, and produced neurochemical effects which were dependent upon the brain area, the treatment duration and the behavioral state.