Neurons are cells in the brain. Neurons use both electrical charges and chemicals called ions to communicate with each other. We say that neurons have an electrochemical charge, and this charge changes, depending on whether the neuron is at rest or is sending a signal. Inside and between neurons there is fluid that contains ions, which are atoms or molecules that have a positive or negative charge. When a neuron is at rest, there are more negative ions inside and more positive ions outside of it, giving the neuronal membrane a negative charge. When brain activity occurs, positive ions rush in through channels in the neuronal membrane and, when the charge gets high enough, the neuron sends a signal to communicate with nearby neurons. Think of this like a match that needs to be struck with just enough force; once it sparks, the whole match catches fire. Electrical stimulation on the scalp can target the electrochemical activity of the brain and alter the charges in neurons without the need for surgery.

License information: CC BY 4.0
MPAA: G
Go to source: https://kids.frontiersin.org/article/10.3389/frym.2019.00062