Histopathologic changes associated with intracerebral injections of 6-hydroxydopamine (6-OHDA) and peroxide (H2O2) in the cat and the rat.

Several factors must be taken into consideration in order to establish whether or not 6-hydroxydopamine (6-OHDA) introduced in the CNS more or less selectively destroys monoaminergic and, more especially, catecholaminergic structures. These include an assessment of all elements possibly damaged following different sites of injection in various species, a comparison with the effects of known neurotoxic agents, the degree of diffusion and/or of dilution of the substance used, the assessment of associated behavioral, neurochemical and morphological changes in the light of the known topography of brain nervous structures etc. A comparison of the effects of 6-OHDA and of peroxide (H2O2) introduced in the CNS suggests that both agents produced similar morphological changes in various sites of the brains of cats and rats. In the light of various data in the literature and of the results reported in this study it appears that 6-OHDA which may be used to induce a focal lesion cannot be regarded as a specific neurotoxic agent.