IMAGING OF THE SEROTONINERGIC NEURONAL SYSTEM IN THE BRAIN

The recently developed method for estimation of brain serotonin synthe sis rate by autoradiography is briefly reviewed. Rats treated by lithi um were used to test the method. As expected, this treatment increased the rate of serotonin in the brain. For the first time we could show that the effect of lithium treatment was not uniform throughout the br ain. An example is also given of extension of the method to measuremen ts by positron emission tomography in dog brain. We demonstrated that the repeated measurements in the same brain were feasible. The increas e in oxygen tension in arterial blood resulted in increased serotonin synthesis rate.