I hope this explanation does not get too complicated, but it is important to understand how neurons do what they do. There are many details, but go slow and look at the figures. Much of what we know about how neurons work comes from experiments on the giant axon of the squid. This giant axon extends from the head to the tail of the squid and is used to move its tail. It can be up to 1 mm in diameter - easy to see with the naked eye.
Neurons send messages through an electrochemical process.
This means that chemicals result in an electrical signal. There are also some negatively charged protein molecules. It is also important to remember that nerve cells are surrounded by a membrane that allows some ions to pass through while it blocks the passage of other ions. This type of membrane is called semi-permeable . When a neuron is at rest, the inside of the neuron is negative relative to the outside.