Grow, you nerve cells
In humans, damaged neurons in the central nervous system rarely regenerate. Researchers are working on very different approaches to eventually be able to heal injuries and diseases of the brain or spinal cord.
After just a few days, the injured area in the brain has healed completely - no trace of scars. Unfortunately, this is not a patient report, but an observation from experiments with zebrafish. The animals can regenerate nerve cells, also known as neurons, and thus restore the functionality of neural networks, which consist of nerve cells that interact with each other. Many other fish and some species of salamander also have this ability.
In humans, on the other hand, injuries to the central nervous system and neurodegenerative diseases usually cause permanent and serious defects: a severing of the spinal cord, for example, leads to paralysis; a stroke, in which nerve tissue in the brain is irrevocably destroyed, often leaves behind permanent damage such as speech disorders and the loss of cognitive abilities. Luckily, for some sufferers, some or all of the impairments resolve over time as pre-existing neural networks restructure.