Neurotransmitters play a crucial role in many neurological functions, but most people don’t know exactly what neurotransmitters are and how they work.
In this guide to neurotransmitters and what they do, you’ll learn about seven vital neurotransmitters and how they impact various functions in your brain, such as learning, memory, mood, and overall cognition.
While the way that each neurotransmitter works is quite similar, the effects that each has are unique. Read on to learn about the most abundant neurotransmitters in your brain and how they impact your mind and body.
What Are Neurotransmitters?
Neurotransmitters are chemicals that allow the cells of your nervous system (neurons) to communicate with the rest of your body. They carry messages from your nervous system to target cells, which may include glands, muscles, or other neurons. Your brain and body speak to each other through neurotransmitters.
Neurotransmitters are released via an electrical signal that reaches the neuron, allowing vesicles (small sacs that contain neurotransmitters) to be liberated from the cell and reach neighboring cells. Like a lock and key system, neurotransmitters dock onto the target cell and produce a change to the cell. This effect can take the form of either excitatory, inhibitory, or modulatory.[1]https://www.ncbi.nlm.nih.gov/books/NBK539894/
- Excitatory— causes an electrical signal to be transmitted down the cell, encouraging the target cell to take action.
- Inhibitory— blocks the electrical signal from continuing, decreasing the cell’s activity.
- Modulatory— affects large numbers of neurons at the same time.
Your nervous system is responsible for a vast array of functions in your body, both physical and psychological, and neurotransmitters are a vital piece of the puzzle. Just a handful of functions in which neurotransmitters play a role include:[2]https://qbi.uq.edu.au/brain/brain-physiology/what-are-neurotransmitters
- Mood
- Heart rate
- Breathing
- Digestion
- Movement
- Sleep
7 Neurotransmitters and Their Functions
1. Acetylcholine
Acetylcholine was the first neurotransmitter ever discovered and plays a role in the central nervous system, autonomic nervous system, and the peripheral nervous system. It has both excitatory and inhibitory actions, so it can either stimulate cell activity or block transmission between cells.
Although it is involved in both the sympathetic and parasympathetic branches of your autonomic nervous system, acetylcholine acts as the primary neurotransmitter in your parasympathetic branch. Your parasympathetic branch is responsible for your “rest and digest” response, as opposed to the “fight or flight” response of the sympathetic branch.
As a parasympathetic messenger, acetylcholine carries out roles such as dilating blood vessels, contracting smooth muscles, increasing bodily secretions, and slowing heart rate. [3]https://www.britannica.com/science/acetylcholine
Acetylcholine also plays an important role in learning and memory. In fact, research suggests that acetylcholine may play a vital role in encoding new memories into storage.[4]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2659740/
Along the same lines, an imbalance in this neurotransmitter seems to play a role in neurological diseases such as Alzheimer’s disease and Parkinson’s disease. Unfortunately, researchers are still investigating how to mitigate this imbalance.[5]https://pubmed.ncbi.nlm.nih.gov/16273023/[6]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2888997/
2. Serotonin
Serotonin is an inhibitory neurotransmitter that plays a key role in mood, helping us feel happy and enhancing feelings of wellbeing. Not surprisingly, imbalances in this neurotransmitter are also found in depression and anxiety.
Serotonin also helps with functions related to your internal clock (circadian rhythm) like sleeping, eating, and digestion. Furthermore, this neurotransmitter plays a role in blood clotting (triggering your arteries to narrow) and bone health (when levels are too high, it can weaken your bones).[7]https://www.hormone.org/your-health-and-hormones/glands-and-hormones-a-to-z/hormones/serotonin
Studies show that when your serotonin levels are too low, you may experience mood issues like anxiety, depression, obsessive-compulsive behavior (OCD), and even suicidal thoughts.
There is also something called serotonin syndrome which can occur when your serotonin levels are too high. This typically occurs in people that take medications that increase these neurotransmitters and includes symptoms like high blood pressure, muscle twitching, heavy sweating, shivering, high fever, and irregular heartbeat. In extreme cases, seizures can even occur.[8]https://www.mayoclinic.org/diseases-conditions/serotonin-syndrome/symptoms-causes/syc-20354758
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3. Dopamine
Dopamine plays a vital role in learning, memory, cognition, as well as emotion.
Imbalanced levels of dopamine can be found in a range of neurological issues, most notably Parkinson’s disease as well as schizophrenia. In addition, dopamine plays a role in addiction, particularly to substances like amphetamines and cocaine.[9]https://pubmed.ncbi.nlm.nih.gov/16106242/
Dopamine is most well known as the “reward” chemical of the brain because it is released when we experience something that either motivates us or causes pleasure. It’s also intimately related to creating memories when we receive a reward for specific behavior. This is one of the ways it’s involved in addiction — you take the drug, it makes you feel good, you remember the good feeling and do it again… and again.[10]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2958859/
4. GABA
GABA (gamma-aminobutyric acid) is another mood-regulating neurotransmitter. It is particularly helpful when you’re feeling anxious or restless because it acts as an inhibitory neurotransmitter, stopping neurons from becoming over-excited.
In fact, benzodiazepines, which are drugs that are often prescribed for anxiety, work by increasing GABA activity in your brain. Specifically, it appears that GABA inhibits the excitatory neurotransmitter glutamate, resulting in more calm and balanced neuronal activity.[11]https://pubmed.ncbi.nlm.nih.gov/12662130/
5. Glutamate
Glutamate is an excitatory neurotransmitter that’s present in most brain synapses, sending signals between cells. When in balance, this neurotransmitter is particularly helpful for learning in memory. However, when glutamate levels get too high, it can cause overexcitation and symptoms like anxiety.
Glutamate is often referred to as an “excitotoxin” because when levels get too high, it can become dangerous to the cells and cause cell death.[12]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4133642/
6. Adrenaline (Epinephrine)
Adrenaline is involved in your “fight or flight” response, which comes from activating your sympathetic nervous system. Your sympathetic nervous system is triggered by something in your environment which induces feelings of stress or fear. When this happens, adrenaline kicks in, increases your heart rate and breathing, and increases the release of glucose into your blood to help you get into survival mode.
Epinephrine (another name for adrenaline) shots are used in anaphylaxis (severe allergic reactions), as well as asthma attacks and arrhythmias, as it can assist in helping with heart contractions.[13]https://www.ncbi.nlm.nih.gov/books/NBK482160/
7. Norepinephrine
Norepinephrine, also known as noradrenaline, works with adrenaline to increase your heart rate and get the blood pumping when you’re faced with a threat. In addition, these two neurotransmitters help with fat breakdown and glucose availability to get you moving when the “fight or flight” response is triggered.
Norepinephrine is also involved in your sleep-wake cycle, helping you wake up from sleep. It also increases your attention and focus and assists with memory storage. As part of your sympathetic nervous system, it keeps you alert so you can manage whatever threat has come your way.[14]https://pubmed.ncbi.nlm.nih.gov/3998066/[15]https://www.sciencedirect.com/science/article/pii/S2352154616302157
There is some evidence that low levels of norepinephrine may be involved in ADHD and general lack of concentration.[16]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4699255/
Takeaway
Neurotransmitters are crucial signaling molecules that your brain uses to send messages between neurons as well as throughout your entire body. When neurotransmitters are out of balance, a range of side effects can occur, from depression to learning disorders to panic attacks.
If you’re experiencing any serious neurological symptoms, it’s best to consult a doctor before trying any over-the-counter supplements. However, if you’re looking to optimize brain function, supplements can offer a simple yet effective solution.
Take this quiz to find a nootropic formula that’s the right fit for you. There is no shortage of nootropics out there, but the ones that work for you will be specific to your current needs.
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