what is a neuron?
I am a neuron, a tiny single cell that carries information to other cells. There are about 30 billion of us in the human brain. We pass on the information to the next cell by using tiny electrical impulses. I am made of three parts. The cell body which is what I live in. Then there's the Dendrites which are extensions that receive the information from another neuron. Finally there are Axons which are like long cables onto which the information leaves me to go to the next neuron. Depending on the type of message needed, I can send and receive information anywhere between 1.6 and 431.3 kilometres per hour. Yet neurons don't touch. To pass on the information I have to rely on my little electrical friends, the Synapses.
The Synapse sits in the gaps between two neurons. When the neuron is excited it produces a chemical and electrical charge. This is carried across the gap to the next neuron by a synapse. It is like the neurons have locks and only the synapses have the keys to open them. Synapses can be likened to a crowd at a sporting event. When the charge starts to leave the neuron they become excited like when a runner rounds the last bend ahead of the field or when there's an open goal in football. Then, as they transmit the message they cheer wildly as the runner wins and the goal is scored. It's like a Mexican Wave inside you. What type of message they are transferring depends on what the body needs at that moment.
Dopamine, Glutamate, Adrenalin.
These are three of the most common chemicals carried by the tiny excited neurons, but what do they do?
Dopamine helps us with movement and concentration and gives pleasure to the brain. Anything you like doing a lot is going to have a lot of neurons passing on a lot of Dopamine.
Glutamate is used for energy, memory and learning. The brain drip feeds us this all the time but will give us more when we are working or concentrating hard. It can also be found in 'energy' drinks.
Adrenalin is used when we are in need of extra energy or strength. If you hurt yourself but have to keep on going then the body will produce adrenalin so that we don't notice the pain. Also, If you are very angry and you lift something heavy that you would not normally be able to, that's adrenalin too.
that's a lot going on.
Yes it is and here's an example. Supposing you are about to touch a very hot kettle, as you put your fingers near it heat is picked up by the neurons in your skin cells. This message is needed quickly so it is rushed back to the brain. The Amygdala gets scared, the Temporal Lobe produces fear and the Hippocampus searches for a memory of this happening. The Neocortex then uses all the information to make a plan. Don't touch the kettle! It then sends a wave through the neurons who connect all the way down using those excited little synapses to the hand which pulls away from the hot surface when it gets the message. Phew. And this all happens in about one millisecond (that's one thousandth of a second!).