Scientists at research center Applied Medicine (CIMA) and Clínica Universidad de Navarra have determined by Positron Emission Tomography (PET) the progression of dopamine deficits in Parkinson's disease from the early stages. The work, developed in animal models, has received the award of research Basic during the congress of the International Movement Disorders Society. The meeting brought together in Paris nearly 3,000 specialists in this discipline.

Parkinson's disease is mainly characterized by the death of dopamine-producing neurons in the brain. Currently, patients are diagnosed when at least 60% of neuronal death has already occurred. The study developed at CIMA and Clínica Universidad de Navarra characterizes the evolution of the disease in the experimental macaque model in different states: healthy, asymptomatic, recovered from the parkinsonian state, with mild parkinsonism and very parkinsonian. "This is the first progressive study with all these Parkinson's disease states performed in an animal model ", explain researchers Carlos Juri and Javier Blesa, from the laboratory of Movement Disorders of the CIMA and authors of the work. Dr. José Obeso, director of laboratory, Dr. Mª Cruz Rodríguez-Oroz and Elena Iglesias, as well as Dr. María Collantes and Elena Prieto, from the MicroPET Unit, led by Dr. Iván Peñuelas, also participated in the study.

The researchers used this non-invasive imaging technique to estimate the amount of dopamine at each stage using two different radiotracers. In addition, they analyzed brain metabolic activity by measuring glucose consumption. In this way, they were able to verify the gradual changes that occur in the brain during the disease. "We have found that there is a progressive loss of dopaminergic neurons and that, apparently, each state has its own metabolic patron saint . According to this study, there are adaptive or compensatory mechanisms that vary as the brain cells die," says Dr. Juri.

According to the CIMA specialist, "the main goal of this line of research is to know in detail what happens in Parkinson's disease before symptoms appear and how the progressive dopaminergic deficit is compensated. In this way, we will be able to propose neuroprotective strategies that enhance the most relevant factors at each stage. It will also serve to optimize the role of PET, which, on occasions, sample some findings that are not consistent with each other".

At present, Javier Blesa is developing the second part of work at theAutonomous University of Madrid. "It consists of verifying the histopathological basis of the PET findings by means of advanced immunohistochemical, stereological and densitometric methods".