Dopamine D1 and D2 receptors in progressive supranuclear palsy: an autoradiographic study
Dopamine D1 and D2 receptors were studied in brain tissue sections from a typical patient with progressive supranuclear palsy and in 7 age-matched brains. The density of D1 receptors in the caudate-putamen and frontal cortex of the patient was within control limits. By contrast, the density of nigral D1 receptors and striatal D2 receptors was dramatically reduced in the patient as compared to the control brains. This work shows again that the loss of striatal D2 receptors is the most plausible explanation for the poor response to dopaminergic drugs in patients with progressive supranuclear palsy. While the loss of nigral D1 receptors can be explained by the loss of nigral neurons, it seems that neurons bearing striatal D1 receptors are spared in progressive supranuclear palsy. The clinical effects of selective D1 agonists are worth testing in this devastating disorder.