Fuorescent retrograde neuronal labeling in rat by means of substances binding specifically to adenine-thymine rich DNA.

Six fluorescent substances, binding specifically to adenine-thymine rich DNA, were injected in rat caudate-putamen. This resulted in retrograde axonal transport and fluorescent retrograde labeling of neurons in center-medium parafascicular nucleus, substantia nigra and dorsal raphe. Two of these substances, i.e. "True Blue' and 'Granular Blue', give a very striking blue fluorescent retrograde neuronal labeling. Mid-thoracic spinal injections of these two substances in rat also resulted in a pronounced retrograde fluorescent labeling of neurons of the descending brainstem pathways and of neurons in the sensori-motor cortex.