A study thesis from the CIMA opens up new avenues for protecting neurons in Parkinson's disease

Parkinson's disease is a neurodegenerative disorder that affects millions of people worldwide, and its incidence is increasing as the population ages. Although one of the main characteristics of the disease is the loss of dopaminergic neurons, evidence suggests that the immune system is involved in the neurodegenerative process.

Adriana Tavira Rodríguez (Pamplona, age 27) holds a bachelor’s degree in Biochemistry (2021) and a Ph.D. in Applied Medicine and Biomedicine (2026) from the University of Navarra. Her thesis , supervised by Dr. Marisol Aymerich Soler, has focused on the role of the immune system during the initial stages of neuronal loss and its influence on the survival of dopaminergic neurons in the nigrostriatal pathway—the neurons that are lost during the course of the disease.

To this end, researchers have studied the changes that occur in the brain’s immune cells and what happens when certain signals that regulate their activity are altered. “We have sought to better understand the relationship between the immune system and neuronal degeneration, especially in the early stages of the disease, when there is still greater potential to protect neurons,” he explains.

However, according to the doctor, not every immune response is necessarily harmful to neurons. “We have observed that modulating certain ‘checkpoints’ of the immune system at the peripheral level can have a beneficial effect at the neuronal level. This approach, based on temporarily stimulating the immune system, promotes the survival of dopaminergic neurons and improves the motor impairments associated with neurodegeneration,” she says.

This research helps broaden our understanding of the mechanisms involved in this neurodegeneration and highlights the immune system as a potential pathway for protecting neurons. “One particularly interesting aspect is that in our model we achieved neuroprotective effects by modulating the immune system from the periphery, without the need to intervene directly in the brain,” he adds.

The next step for the research will be to delve deeper into the mechanisms that explain how the modulation of the immune response can protect neurons: which cells are involved in this effect, how they communicate with each other and with brain cells, and what changes occur in their function. They will also determine whether these mechanisms persist across different stages of the disease and whether the results obtained in experimental models are relevant to Parkinson’s disease in humans.
 

Bibliographical references

· Tavira, A., Basurco, L., Abellanas, M. A., Ayerra, L., Vidaurre, C., Luquin, E., Vales, A., Gonzalez-Aseguinolaza, G., Marrodan, L., Alonso, M. M., Mengual, E., Tansey, M. G., Hervás-Stubbs, S., & Aymerich, M. S. (2025). Inhibition of T-cell infiltration and soluble TNF signaling is neuroprotective in the alpha-synuclein-overexpressing mouse model of Parkinson's disease. NPJ Parkinson's Disease, 11(1), 315. 

· Ayerra, L., Abellanas, M. A., Vidaurre, C., Basurco, L., Tavira, A., Luquin, E., Clavero, P., Mengual, E., Collantes, M., Peñuelas, I., de Martin-Esteban, S. R., Grether, U., Hillard, C. J., Romero, J., Hervás-Stubbs, S., & Aymerich, M. S. (2025). Activation of central cannabinoid type 2 receptors, but not on peripheral immune cells, is required for endocannabinoid-mediated neuroprotection in Parkinson’s disease. Brain, Behavior, and Immunity, 128, 600–611.

· Ayerra, L., Abellanas, M. A., Basurco, L., Tamayo, I., Conde, E., Tavira, A., Trigo, A., Vidaurre, C., Vilas, A., San Martin-Uriz, P., Luquin, E., Clavero, P., Mengual, E., Hervás-Stubbs, S., & Aymerich, M. S. (2024). Nigrostriatal degeneration determines the dynamics of glial inflammatory and phagocytic activity.Journal of Neuroinflammation, 21(1), 92.