[Evaluation of motor disorders in animal models of Parkinson's disease]

The diagnosis of Parkinson's disease is essentially clinical, that is to say, it is based on the observation of the motor alterations displayed by patients, and for this reason it is considered to be a simple matter. Yet, only 75% of the diagnoses that are carried out clinically are later confirmed in the autopsy. Animal models can be generated by systemic or intracerebral application of neurotoxins, like 6-hydroxydopamine (6-OHDA) for rats or 1-methyl-4-phenyl-1,2, 3,6-tetrahydropyridine (MPTP) for mice and non-human primates, which induce damage in the nigrostriatal dopaminergic system. This gives rise to a variety of motor symptoms such as akinesia, bradykinesia, rigidity, tremor, gait disorders and abnormal postures, which is what makes the evaluation of the changes in the signs of Parkinsonism in animal models such a challenge to researchers today.

The paper reviews the variety of paradigms available for evaluating these symptoms in mouse, rat and non-human primate models, which have been used to measure the differences brought about by applying neurotoxins and, in some cases, the improvements produced by different treatments for the Parkinsonian syndromes that were induced.

Both the general findings of these works and the factors that influence the trials are discussed, together with the potential problems and benefits that the experimental procedures may have.