Inhibitory and Disinhibitory Effects of Nitrazepam, Diazepam and Flurazepam Hydrochloride on Delayed Matching Behaviour in Monkeys (Macaca - mulatta),

The effect of three benzodiazepines, nitrazepam 0.15, 0.45 and 0.75 mgkg, diazepam 0.6, 1.8 and 3.0 mgkg and flurazepam 0.45, 1.35 and 2.25 mgkg on total response time and on the accuracy of response on a delayed matching task has been studied in monkeys macaca mulatta. Increased total response time was observed after all three doses of diazepam and particularly nitrazepam, but after flurazepam increased total response time was limited to the highest dose 2.25 mgkg. Accuracy of response on delayed matching was impaired by all three drugs. The effect of diazepam and flurazepam was limited to the highest dose in each case, but with nitrazepam performance was impaired also after 0.45 mgkg. The effect of the three benzodiazepines on delayed matching was related in a complex way to the delay between stimuli and to the response demanded GO OR NO-GO.