Question: how does our body generate neurons?

Emily Graves answered on 7 May 2020:

This is a really good question!

Neurons are a special kind of cell called ‘post-mitotic’. This means that they cannot replicate like cells in other parts of the body, for example, your skin!

Most of the neurons in our bodies are generated during embryo development in pregnancy. This process is called neurogenesis, during pregnancy on average 250,000 neurons are generated per minute! A special type of cell called a neural stem cell (NSC) has the ability to develop into other types of neural cell, including neurons! During development, lots of complicated signalling and migration pathways work together to create the nervous system. Babies actually have way more neurons than we do as adults as these are ‘pruned’ as we learn things, leaving us with the most efficient connections. This allows our brains to function the best they can.

An adult body can still go through this process of neurogenesis, but it is much more limited than during development. This process is less well studied, but it seems like it only occurs in two regions of the brain. These neurons are involved in memory formation, and your recognition of smells!

As neurons cannot replicate, once they die it can cause devastating diseases like Alzheimer’s disease or Motor Neuron Disease. The symptoms of these diseases (memory loss and paralysis) are caused by the death of neurons within your nervous system. So its really important for scientists to understand more about how the body generates neurons as maybe one day it can help us treat these patients!