How Do Brain Cells Communicate With One Another?

Understanding the process of neurotransmission

How do brain cells communicate with one another to create thoughts, feelings, and behaviours?

They communicate by means of a process called neurotransmission.

Neurotransmission — the transmission of nerve impulses between neurons or between a neuron and a muscle fibre or other structure — could not occur without unique cellular structures called receptors (a molecule in cells that serves as a docking station for another molecule).

Neurotransmission begins when one brain cell releases a neurochemical into the synapse (the space in between neurons.) But for a neighbouring cell to “pick up” the message, that neurochemical must bind with one of its receptors.

When an electrical signal reaches the end of a neuron, it triggers the release of tiny sacs that had been inside the cells. Called vesicles, the sacs hold chemical messengers such as dopamine or serotonin.

This drawing shows a synapse — the space between two cells. The chemical messenger dopamine is inside the top cell. Receptors on the bottom cell are waiting to receive it.
Image Credit: NATIONAL INSTITUTE ON DRUG ABUSE

As it moves through a nerve cell, an electrical signal will stimulate these sacs. Then, the vesicles move to — and merge with — their cell’s outer membrane. From there…