Our brain cells neurons and the connections between them are constantly changing, which enables us to learn and remember, acquire new skills, and recover from brain injury.
It's a property referred to as 'neuroplasticity' — the ability of the brain and nervous system ability to remodel in response to new information, whether that be due to experiences, behaviour, emotions, or injury. One of the methods the brain does this is through a process known as neurogenesis — the creation of new neurons. Neurogenesis is a particularly important process when an embryo is developing. Until only recently, it was thought that the number of neurons we're born with is fixed — that the central nervous system, including the brain, was incapable of neurogenesis and unable to regenerate.
But neuroscientists led by QBI's founding director, Professor Perry Bartlett , discovered stem cells in the hippocampus of the adult brain in the s. Neurogenesis is now accepted to be a process that occurs normally in the healthy adult brain, particularly in the hippocampus , which is important for a learning and spatial memory.
Damage to the hippocampus can lead to difficulties with navigation, as Dr Lavinia Codd found when, at age 31, she had a stroke that damaged her right hippocampus. Create a personalised content profile.
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Recent Blog Articles. Why is topical vitamin C important for skin health? Preventing preeclampsia may be as simple as taking an aspirin. Caring for an aging parent? Tips for enjoying holiday meals. A conversation about reducing the harms of social media. This process is called plasticity , and it helps the brain to adapt to the loss of neurons. Forget for a moment about dying cells, the responsibility for plasticity lies entirely with the surviving cells.
How does this work? Apart from growing new arms to connect with new cells, neurons can also modify the strength of existing connections with other neurons Figure 3. They can either strengthen such connections or they can weaken them, resulting in a totally new network of connections in the brain. This plasticity is driven and directed by activities that we perform. After a stroke or brain injury, patients usually improve to a certain extent doing some sort of physical therapy.
The improvement is not so much due to growth of new neurons, as you learned above, but because these patients keep stimulating plasticity and, therefore, build new connections between surviving neurons in their brains!
Unfortunately, plasticity as a repair mechanism has its limits. Plasticity relies entirely on surviving cells, so the more surviving cells there are, the better. If someone suffers a severe brain injury, or a huge stroke that kills a substantial amount of brain cells, then there are less surviving neurons available for plasticity than following a mild concussion.
The more cells available for plasticity to work with, the more plasticity can occur. This is why severe central nervous system injuries usually result in lasting disabilities. And because the consequences of these severe injuries are so dire, scientists are working hard to try to protect neurons from dying, to replace lost cells with stem cells, to help injured neurons grow, and to stimulate plasticity. The spinal cord is mainly responsible for picking up all kinds of feelings from your body and sending it to the brain for processing, as well as for sending movement commands from the brain to your arms and legs.
This network of connected neurons is the basis of all the work that the central nervous system performs so you can think, move, and feel things. If you have a bad concussion, you may see stars in front of your eyes, you may not remember what day it is, and you may feel nauseous. The nerve cells in that region die off quickly if they stop receiving essential things like sugar and oxygen from the blood. Most of these challenges are complicated chemical processes.
They can develop into any professional cell, including neurons, when scientists treat them with specific molecules. For example, this sheath is what allows you to react quickly when you hurt yourself, such as pulling back your hand from touching a hot stove top.
Astrocytes are support cells in the brain that are very different from neurons. They support neurons in many ways, such as by keeping harmful molecules away.
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