Neuroscientist Ernest Arenas had his life changed by a patient with congenital analgesia, the fakir disease. "I was a person who did not perceive physical pain, I was fascinated," he recalls. He had never heard of this disease and started looking for information. There were hardly any studies on it. He consulted the neuropathologist Isidre Ferrer, from the Bellvitge hospital, who had been one of his professors during his medical studies. Ferrer asked:
-Ernest, do you want to cure this patient or understand what is wrong with him?
After a moment of doubt, because until then he had not considered it, Arenas replied:
I think I understand what's wrong.
"Well, maybe you should consider dedicating yourself to research," Ferrer advised him.
That conversation helped Arenas discover his true vocation. Thirty-five years later, he runs a laboratory at the Karolinska Institutet in Stockholm, where he is also a member of the Nobel Assembly that awards the Nobel Prizes in Medicine, and is recognized as a world leader in Parkinson's research. This week he presented his latest discoveries on the diversity of dopamine-producing neurons in the human brain at the Parkinson's World Congress held in Barcelona.
"The brain is a continent to be explored," declares Arenas. Until recently we did not even know its geography. Now that we're getting to know her, we can decide what we're going to look for. But we don't know what we're going to find.
The geography of the brain that serves as a guide to Arenas are the different types of cells that form it. According to the results that he presented at the Barcelona congress, there are at least 14 different types of neurons that produce dopamine, the neurotransmitter most affected in Parkinson's, and not just 10 as previously described.
The next objective of this line of research, he points out, is “to understand how Parkinson's originates, and in what type of cells, in order to develop effective therapies; but we are still far away, we have a lot to discover ”, she warns.
After that conversation with Isidre Ferrer about the patient who did not know pain, Arenas began to investigate neurotransmission in the basal ganglia of the brain, the field to which he has dedicated his entire career and in which he continues to work today. “I really liked the brain, understanding how it works and how we perceive the world,” he recalls.
When he finished his doctorate, he decided to go abroad with his wife, also a neuroscientist Carmen Saltó, to further his training as a postdoctoral researcher. They ended up at the Karolinska Institute in Stockholm, with the intention of staying there for only two years. But they found a research environment that was inconceivable in Spain at that time, with sufficient resources to address important scientific questions and constant interaction with researchers from other groups.
He identified a protein that prevents the death of neurons, published the discovery in Nature and obtained a professorship to stay at the Karolinska. From there he now advises scientific institutions in Catalonia such as the Bellvitge Research Institute (Idibell), Vall d'Hebron (VHIR), Lleida (IRBLleida) or the Institute of Neurosciences of the University of Barcelona. “I try to help as much as I can,” he says.
His research focuses on exploring how dopamine-producing cells are formed to regenerate the brain because, "by the time Parkinson's is diagnosed, half of these neurons have already died."
Although current therapies alleviate symptoms and help preserve patients' quality of life, they do not prevent the disease from progressing. But if damaged neurons are regenerated, it could possibly make patients better rather than worse.
To do this, Arenas investigates how to form dopamine-producing neurons from human stem cells, an area in which his laboratory was a pioneer. The transplantation of these cells to people with Parkinson's could become an effective treatment against the disease in the future. In addition, neurons generated in the laboratory will be useful for investigating the efficacy of candidate drugs against Parkinson's.
Going forward, "we need to keep all treatment options open," says Arenas. “To improve the quality of life of patients with a disease as complex as Parkinson's, we do not think that a single type of therapy will solve all cases. We are probably going to need both cellular and pharmacological treatments.”
