Cajal's Challenge
Dan Lewis Foundation | Spring 2024

Overcoming the Barriers in Making New Neurons in the Adult Brain: Lessons from Nature


Almost 100 years ago, the father of modern neuroscience Santiago Ramón y Cajal, a Spanish physician, recognized that the injured brain could not repair or regrow damaged neurons. Cajal stated, “In adult centers the nerve paths are something fixed, ended, immutable. Everything may die, nothing may be regenerated. It is key for the science of the future to change, if possible, this decree.”¹ Cajal recognized that for individuals with devastating brain diseases or brain injuries, there was little that could be done to repair or regenerate neurons. He proposed that it was up to future scientists to solve the problem of regeneration. There lies Cajal’s Challenge. 


The Federation of European Neuroscience Societies (FENS) will meet in Vienna from June 25th to 29th, covering all areas of neuroscience from basic to translational. On June 24th, a one-day pre-FENS workshop will be held with 100 young researchers. This one-day meeting, started in 2021, is designed to create a strong and interactive community among young researchers in the fields of neurogenesis and glia to neuron conversion in Europe, the U.S., and beyond. Our vision is to promote the free exchange of ideas and results among the research groups working in this area. Neurogenesis and Glia-to-Neuron conversion is one of the most exciting research fields of our times.

Cajal’s Challenge Speakers:

Alejandro Schinder, PhD

Benedict Berninger, PhD

Don Cleveland, PhD

Enric Llorens, PhD 

Elly Tanaka, PhD

Magdalena Gotz, PhD

Noelia Urban, PhD

Sumru Bayin, PhD

Sofia Grade, PhD

Sven Falk, PhD

For more information and free registration: 

https://roymaimonel.wixsite.com/cajalschalange


1. Ramón y Cajal S.

Degeneration and Regeneration of the Nervous System.

Haffner Publishing Company, New York, NY1926


Gloved hands hold a tablet showing medical data in a lab with blurred researchers in the background

ARPA-H Launches a Major Program in Brain Regeneration and Initiates a Second Offshoot Program

By Dan Lewis Foundation • July 24, 2026
ARPA-H, which stands for Advanced Research Projects Agency for Health, is an agency within the U.S. Department of Health and Human Services. One of its major projects is called the FRONT program which stands for Functional Repair of Neocortical Tissue .  The FRONT program focuses on repair and regeneration of the neocortex, the largest part of the brain. The neocortex is critical for many aspects of cognition and everyday functioning. The neocortex can be damaged in many ways including stroke, traumatic injury, and neurodegeneration, such as in Alzheimer's disease. Serious damage to the neocortex often causes individuals to be dependent on costly therapies or caregivers and can also lead to related health and medical problems. The FRONT program hopes to alter this pattern by using cutting-edge neurodevelopmental principles and stem cell technology to regenerate brain tissue and restore lost functions.
Lab technicians in blue gloves working with samples in a bright laboratory

Can Lost Brain Tissue Be Rebuilt?

By Hal Lewis • July 24, 2026
For decades, families facing severe traumatic brain injury have lived with a painful assumption: once brain tissue is lost, recovery is limited to what the surviving brain can re-learn. Rehabilitation can help. Technology can assist. Time can produce surprises. But the central wound—the loss of brain cells, circuits, and connections—has often been treated as permanent. That assumption is beginning to change.