Chronic methods to study the release of catecholamines from the neostriatum in nonanaesthetized monkeys (Macaca mulatta)

The present report describes two methods allowing the chronic collection of catecholamine (CA) released from the neostriatum in the nonanaesthetized monkey (Macaca mulatta). In both methods the monkeys were placed in a restraining chair. Indwelling electrodes allowed the correlation of behavioural observations with polygraphic recordings. The first method uses a special superfusing cup permanently implanted on the lateral surface of the caudate nucleus, which permits the demonstration of spontaneous and D-amphetamine-induced release of (3H)-dopamine (DA) newly synthesized from L-(3,5-3H)-tyrosine over a period of six days. In the second method the collection of unlabelled CA is carried out by a localized ventricular perfusion. A radio-enzymatic estimation enabled the measurement of unlabelled DA and noradrenaline. With this second method the animals were kept for 25 to 30 days.