The brain communicates with itself by transmitting chemicals from one neuron, or nerve, to the other. This regular, rapid-fire messaging plays a big role in how you feel and function each day.
These neurotransmitter chemicals are classified into two basic categories:
- Excitatory, meaning they stimulate brain activity.
- Inhibitory, meaning they have a more calming effect.
Learn more about a few common brain chemicals and how they impact your thinking and mood.
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Six Important Brain Chemicals
You probably already know that serotonin plays a role in sleep and in depression, but this inhibitory chemical also plays a major role in many of your body’s essential functions, including appetite, arousal, and mood. Many antidepressants target serotonin receptors to improve your mood and lessen depressive symptoms.
Interestingly, most of your serotonin is stored in the intestine, and this chemical may play a role in digestive functioning as well.
Dopamine controls many functions, including behavior, emotion, and cognition. This chemical also communicates with the front part of your brain, which is associated with pleasure and reward. On the positive side, it helps motivate you to work toward achieving a reward. However, many substances also target dopamine receptors, which contributes to drug and alcohol dependency and addiction. Because dopamine is related to movement, low levels also have been linked to Parkinson’s disease.
Gamma-aminobutyric acid (GABA)
GABA is the most common inhibitory neurotransmitter of the brain and nervous system. It is both an important part of the visual system and muscle control. GABA helps prevent anxiety, increases concentration, and aids with sleep, depression, and even seizures. Drugs that increase the production of GABA can be used to help people with epileptic seizures and tremors in patients with Huntington’s disease.
Acetylcholine is an excitatory neurotransmitter, with many functions for both the central and peripheral nervous system. This neurotransmitter plays a role in sleep, learning, memory, and muscle contractions. An imbalance of acetylcholine can be linked to muscle spasms, seizures, and is even an indicator of Alzheimer’s disease.
This is the most common excitatory neurotransmitter, found throughout your brain and spinal cord. Glutamate has many essential functions, including early brain development, cognition, learning, and memory.
This chemical, also called noradrenaline, can sometimes act as a hormone as well. Its primary role is to control your body’s stress response. It works with the hormone adrenaline to create the “fight-or-flight” feeling. Norepinephrine may also be used as a drug to raise or maintain blood pressure in certain illnesses.
Chemicals, Hormones, and the Brain
Some of these neurotransmitters, such as norepinephrine, are also hormones or have some effect in releasing hormones in the body. Adrenaline, cortisol, melatonin, and other hormones can affect your mood or even influence the health of your brain.
- Adrenaline is a hormone secretedby the adrenal glands, especially in times of stress. It increases the rates of blood circulation, breathing, and carbohydrate metabolism and prepares muscles for exertion.
- Cortisol is a hormone released when you’re stressed. It’s helpful at times, but too much of it for too long can cause memory loss as you age.
- Melatonin is a hormone that your brain produces in response to darkness. It helps with the timing of your body’s circadian rhythms or internal clock and with sleep. Being exposed to light at night can block melatonin production.
Imbalances in neurotransmitters are present in many conditions, including schizophrenia, depression, bipolar disorder, autism, and Parkinson’s disease. Some medications target these receptors to allow your body to receive more or less of certain chemicals, while some drugs act similar to these chemicals to invoke similar responses in your body.
For people experiencing tremors or seizures related to Tourette syndrome, Parkinson’s, or Huntington’s disease, there is a treatment know as deep brain stimulation (DBS), which involves the implantation of electrodes on the brain to target specific areas with electrical impulses. These impulses stimulate the affected area to restore or improve proper function, and can help treat the effects of conditions like dystonia, epilepsy, or essential tremor. The use of DBS can restore balance to the brain chemistry.
What You Can Do
You can help maintain your brain chemical health to some extent through eating a balanced diet, limiting your stress, getting enough uninterrupted sleep, and exercising. Maintaining a balance in brain chemicals and hormones is key to feeling balanced in your mood.
Editor's Note: This article was originally published on , and was last reviewed on .
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