How does the brain work?

Human brains and the brains of most animals are complex combinations of chemicals, nerves blood vessels and tissue that guide us through our activities by receiving and sending information. The signals may come from within our bodies, or through the senses of sight, touch and hearing.

Various sections of this primary human organ control different actions, thoughts and responses. One part of the brain receives information from our eyes, processes this and completes the seeing process so we can understand what we are looking at. Another part of the brain works with information that we receive through reading or hearing and helps us form ideas and opinions based on what we take in.

The foundation of brain function is electrical in nature. A human brain might contain as many as 100 billion nerve cells (also known as neurons). These individual cells communicate with each other, carry messages in what scientists call the “electrochemical” process. Brain activity is possible because a few select chemicals, such as sodium, chloride, potassium, travel to and then into the cells, ultimately moving out and returning along the body’s nerves. This completes a path that closely resembles an electrical circuit.

Neurons exist in different types. Some are devoted to handling information from our senses only. Others deal with memory or work internally, after the various messages reach the brain. Research has long focused on how individual neurons function when specific electrochemical signals arrive.

In the brain, the synapse is a junction or tiny space across which the neurons signal to each other. According to medical texts chemical synapses are a key ingredient in the nervous system, allowing it to form the circuits necessary for efficient operation. In basic terms, a neuron releases the chemical element called a neurotransmitter. This crosses the synapse to another neuron.

This exchange of chemicals happens thousands upon thousands of times, repeating as the synapse is cleared and ready for another signal. Among the key elements in this activity are the calcium ions that flow through the tissue and increase in concentration. This high level of a particular calcium ion causes the formation of the necessary neurotransmitter, which must be formed by the correct combination of chemicals.

When this stage is reached the chemicals move into the opening of the synapse. The signal, in the form of chemicals, binds to the receiving part of another neuron, continuing the electrochemical circuit. The receiving molecule activates and the process continues.

All of this happens in a second or a fraction of a second and the brain has to process the signal, compare it to information already there, store it or send it back to the body so that we can react based on the input to the brain. The reverse process is similar to the process that takes electrochemical signals to the brain. If all of the necessary components are at their proper levels, the brain might have signalled us to raise our arm. It’s complex and so fast it still amazes even the most knowledgeable among us.