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


A man is holding a fish in his hand in front of a lake.
By Dan Lewis Foundation November 6, 2024
After a life-altering accident in October 2022, Devon Guffey’s story is about resilience and determination. His journey has been profiled in the summer 2023 issue of the Making Headway Newsletter: https://www.danlewisfoundation.org/devons-story . Hit by a drunk driver, Devon sustained severe brain and physical injuries, including axonal shearing, a traumatic frontal lobe injury, and facial fractures. Even after contracting meningitis while in a coma, Devon fought hard to survive – and today, his recovery continues to inspire us all. In late 2023, Devon worked as an assistant basketball coach at Blue River Valley, where he had once been a student. His love for sports and dedication to regaining his physical strength returned him to the gym, where his hard work paid off. Devon’s persistence earned him another job at the YMCA, guiding gym members and supporting facility upkeep. Through all the challenges—deafness in one ear, blindness in one eye, and a permanent loss of taste and smell—Devon perseveres. He recently regained his driving license, a significant milestone that symbolizes his increasing independence and cognitive and physical recovery. While each day may not show significant changes, Devon now sees his progress over time. Today, Devon speaks to groups about his journey, the dangers of drunk driving, and finding strength in adversity. His message is clear: recovery is a process, and sometimes, "can't" simply means "can't do it yet ." Every TBI is unique, and Devon’s story powerfully reminds us of the strength that comes from resilience and community. We are grateful to Devon for continuing to share his story and for his role in uplifting others facing difficult paths. His journey is a testament to the fact that we are stronger together. #BrainInjuryAwareness #DevonsJourney #Resilience #EndDrunkDriving #MakingHeadway
A close up of a brain with a lot of cells and a purple background.
By Dan Lewis Foundation | Summer 2024 July 10, 2024
Scientists worldwide are working to find ways to stimulate healing and functional recovery after severe brain injuries. This work is driven by the desperate needs of persons who have suffered brain damage. It is inspired by the knowledge that the information required to create new brain cells, cause these cells to interconnect, and stimulate new learning is contained in our genome. Now that we can readily generate stem cells from adult tissue, we have access to the genomic program that can control all of the intricate details of brain tissue formation. A number of different research themes are being pursued productively. These include: (1) enabling injured neurons to self-repair (“axonal repair”) 1,2 ; (2) replacing damaged tissue by increasing the growth of new neurons (“neurogenesis”) 3-5 ; (3) transplanting new brain cells that are derived from a person’s own stem cells (“autologous cellular repletion”) 6-8 ; (4) stimulating the re-wiring of new or surviving tissue by encouraging the formation of new connections (“synaptogenesis”) 9,10 ; and (5) augmenting the function of a damaged brain by the use of bio-computational prostheses (“brain-computer interfaces”) 11,12 ; We’ve explored these themes in previous newsletters. The goal of stimulating meaningful brain regeneration is now sufficiently plausible that a large-scale, well-funded campaign needs to be funded to bring meaningful new therapies to patients within the foreseeable future. Here, we suggest a high-level outline of the research themes for such a campaign. A ‘moon shot’ program towards brain regeneration would leverage cutting-edge technologies in stem cell research, gene therapy, synaptic plasticity, neuronal repair, and brain-computer interfaces (BCIs) to develop innovative treatments for brain injuries and neurodegenerative diseases. These treatments would target the restoration of lost brain functions and improvement in the quality of life for individuals affected by severe brain injuries. This research agenda aims to catalyze serious discussion about creating a federal program with funding, organizational resources, and expert governance to enable brain regeneration in our lifetimes. Major Themes For a Brain Regeneration “Moon Shot” Program 1: Promote the formation of new neurons 1.1 Stimulate the brain to create new neurons 1.2 Create new neurons from patient-derived induced pluripotent stem cells to be transplanted back into the patient. Create new glial cells to support neurogenesis. 2: Stimulate new synaptic formation 2.1 Develop drugs that enhance synaptic plasticity and promote the formation of new synaptic connections 3: Stimulate self-repair of damaged neurons 3.1 Develop drugs that de-repress neurons and, thereby, enable axonal regrowth 4: Develop brain-computer interfaces (BCIs) for brain-injured patients 4.1: Develop and test BCIs that enable the brain to control behaviors or external devices and, thereby, augment or replace impaired functions. 4.2: Develop and test BCIs that can accelerate the training of remapped brain tissue in persons with brain injuries to optimize functional recovery. 4.3: Combine BCIs with other strategies (e.g., cell repletion, synaptogenesis, and enhanced plasticity) to accelerate adaptation and functional improvement. The proposed research themes can underpin targeted research to stimulate meaningful brain regeneration, offering new hope for patients with brain injuries and neurodegenerative diseases. While the scientific challenges are profound, there has been sufficient progress to justify substantial investment in brain regeneration research. Any such large-scale program will require coordinated collaborations among academic and commercial partners, skillful governance and management, and a shared sense of profound commitment to the goal. The recent pace of advances in cell biology, stem cell technology, bio-computational interfaces, and genomically targeting medicines suggests that large-scale investment will yield meaningful clinical advances toward brain regeneration after injury. With robust funding and skilled leadership, this comprehensive research agenda has a realistic potential to transform scientific breakthroughs into tangible medical therapies, offering hope to millions affected by brain damage.
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