Non-specific histopathological changes induced by the intracerebral injection of 6-hydroxy-dopamine (6-OH-DA)

The hypothesis that 6-OH-DA injected intracerebrally more specifically destroys catecholaminergic neurons is not supported by the data disclosed in this study.

Abstract

The injection of 6-hydroxy-dopamine (6-OH-DA) directly into the brains of rats and cats results in necrosis of all tissue surrounding the site of the injection. Under such conditions monoaminergic cells degenerate only in so far as their cell bodies or their axonal processes are within the area of destruction resulting from the injection of 6-OH-DA. In this regard 6-OH-DA-induced lesions are not different from lesions produced by electrocoagulation. The injection of 6-OH-DA into the lateral ventricle of the brain results in the destruction of the ependyma and the adjacent nervous tissue at the level of the corresponding injected ventricle and foramen of Monro, the third ventricle, the cerebral aqueduct and the fourth ventricle. It is also associated with an enlargement of the whole ventricular system. Therefore the hypothesis that 6-OH-DA injected intracerebrally more specifically destroys catecholaminergic neurons is not supported by the data disclosed in this study. The toxic effect of 6-OH-DA is more likely to be related to the formation of peroxide (H2O2) as a consequence of its rapid auto-oxidation at pH 7.