[3H]Dihydrotetrabenazine, a new marker for the visualization of dopaminergic denervation in the rat striatum

[3H]Dihydrotetrabenazine ([3H]TBZOH), a derivative of the monoamine depleting agent, tetrabenazine, has been shown to bind to the vesicular monoamine transporter. We studied the effect of unilateral nigral lesion with 6-hydroxydopamine on [3H]TBZOH binding in the striatum by means of quantitative autoradiography. Topographical analysis of striatal [3H]TBZOH binding showed in control rats a pattern similar to the known distribution of dopaminergic innervation, and allowed to visualize dopaminergic denervation in lesioned rats. A good correlation was found between striatal [3H]TBZOH binding levels and tyrosine hydroxylase activities in similar areas on adjacent slices following 6-OHDA lesions with varying severity. These data reveal that autoradiography of [3H]TBZOH binding is a good index for the visualization and quantitation of dopaminergic nerve terminals integrity in the striatum.