Yes, humans can grow new nerves, but the extent and location vary significantly. While the brain and spinal cord have limited regenerative capacity after injury, unlike nerves in other parts of the body (like a cut finger which heals), research indicates ongoing neurogenesis (the process of forming new neurons) throughout life, albeit at a slower rate than during prenatal development.
Neurogenesis: The Creation of New Neurons
Numerous studies support the ongoing process of neurogenesis in specific brain regions, such as the hippocampus, which plays a critical role in learning and memory. This study shows that neurogenesis continues even in older adults, including those with mild cognitive impairment or Alzheimer's disease. This process involves the creation of new neurons from neural stem cells or precursor cells. This article from the National Institute of Neurological Disorders and Stroke (NINDS) confirms this, stating that while most neurons are formed before birth, evidence supports lifelong neurogenesis.
Several factors influence neurogenesis, including:
- Exercise: Studies indicate exercise promotes neurogenesis and can improve cognitive function. NIH research highlights this positive effect.
- Age: The rate of neurogenesis declines with age, but it doesn't cease entirely.
- Environmental factors: Various environmental factors can also influence neurogenesis rates.
Nerve Regeneration Outside the Brain and Spinal Cord
Outside of the central nervous system (brain and spinal cord), peripheral nerves have a greater capacity for regeneration. If a peripheral nerve is damaged, it can regrow, allowing for functional recovery. However, the extent of this regeneration depends on the severity and location of the injury.
Challenges in Nerve Regeneration
While neurogenesis and peripheral nerve regeneration are possible, there remain significant challenges, particularly in the central nervous system. The limited regenerative capacity of neurons in the brain and spinal cord after injury presents a major obstacle in treating conditions like spinal cord injury. Researchers are actively working to overcome these challenges. For example, research at Washington University focuses on identifying and manipulating key genes to promote nerve regrowth.
Advancements in Nerve Regeneration Research
Ongoing research continuously expands our understanding of nerve regeneration. For example, recent studies have shown success in growing lab-grown eye cells that form new neural connections NIH research and the use of lab-grown human nerve cells to accelerate the development of new treatments. See this NIH Seed portfolio story.
