• Question: How do nerves repair themselves?

    Asked by livi to Sam, Callum on 22 Nov 2012. This question was also asked by tigatrotsky.
    • Photo: Sam Godfrey

      Sam Godfrey answered on 22 Nov 2012:

      The nerves outside of your brain and spine are quite good at repairing. If you think of the nerve cell, it has a little round body and a great long arm that touches the next cell. It’s along this arm that the nerve impulse flows. In nerve damage, the arm gets snapped off. Now in the peripheral nervous system (thats the part that makes you move legs and arms and feel things) we have special cells called schwann cells who help look after the nerve and speed up the nerve signal. When a nerve cell is broken, they switch into repair mode and release all sorts of special growth chemicals to help the nerve cell. They also form a special pathway, a bit like a railway line, which helps the nerve cell grow in the right direction until it reaches the rest of the nerve again. This system is quite good and really impressive but in the central nervous system (brain and spine) it doesn’t work like that. Their aren’t any schwann cells to help and the nerve cells stick very tightly to the surrounding cells meaning they don’t grow back. This is why paralysed people and people with brain damage find it harder to recover. with brain damage, sometimes the brain learns to reprogramme itself and can get around the damage and function normally, but often that is hard. So our project is trying to find a way of making the nerve cells not hold so tightly to the sorrounding cells and start to regrow.

    • Photo: Callum Johnston

      Callum Johnston answered on 23 Nov 2012:

      Nerve cells aren’t very good at repairing them selves. Everything that goes on inside the cell is well balanced but if something goes wrong that balance is disturbed. If they have a genetic defect which stops them making a certain protein they might make a different protein with a similar job to compensate, but too much of that protein might have other bad effects on the cell which cause more damage. Also the brain doesn’t store any energy in the form of fat (unlike the rest of the body) so when it doesn’t get any glucose from the blood they struggle to keep themselves alive. Again when the blood does return, they try and compensate for the loss but they sometimes over do it and cause more damage.

Comments

  • Photo: mollibear

    mollibear commented on :

    why do we sneeze?

  • Photo: Sam

    Sam commented on :

    Hey Mollibear

    We sneeze usually because of something irritating our nasal passage. It’s semi autonomous which means that you don’t have to think about it, but do retain some control (cos you can hold back a sneeze sometimes if you have to.) Basically the cells in the nasal passage are wired directly to the brain and if something irritates them like a bit of dust or pollen, then it makes your brain cause you to release lots of air to try and dislodge whatever is tickling the nose. If you have a virus, often the virus hits the mucosal cells which are the ones in your nose throat and lungs and they react in the same way. Some people sneeze because of other things like plucking eyebrows, bright light and even chewing gum. With these, we aren’t exactly sure why people sneeze but it’s probably due to a slight cross over of nerves. Did you kow that one lady sneezed non stop for 978 days!