Brain The soft, wrinkled three-pound brain inside your head is your mind, your personality and your body's boss. From speaking and seeing, to thinking and remembering, your brain controls what you do. Can you imagine billions of neurons sending out trillions of messages every minute? You certainly can because your brain gives you an incredible imagination! Dopamine Dopamine is an essential neurotransmitter, a brain chemical that helps neurons communicate with each other and with other cells. Dopamine plays a role in pleasure, movement, motivation and cognition. Activities that cause the release of dopamine include exercising, cooperating, having healthy relationships, and eating or even just anticipating eating sweet foods. Serotonin Serotonin is a neurotransmitter that influences your mood, memory, sleep and cognition. It can constrict blood vessels and regulate body temperature. Because serotonin helps control the stream of information moving across the pathways of the brain, it exerts a powerful effect on your thoughts and state of mind. Certain activities may help boost serotonin levels such as smiling and exercise. Glial Cell Your brain is more than just neurons. It includes blood vessels, fluids and glial cells. Over 50 billion of these cells support neurons in ways that we do not fully understand. There are several types of glial cells. Oligodendrocytes produce the nerve insulation called myelin and help neurons transmit signals. Microglia are the brain's own immune system. Astrocytes are the largest and most prevalent glial cell. These star-shaped cells have roles that include releasing neurotransmitters, helping to modulate nerve signals, and controlling blood flow. Neuron The little grey cells that make up your brain are primarily neurons. You have over 80 billion of them. The typical neuron is connected to thousands of others forming an inconceivably dense signal-processing network.