Acetylcholine: What It Is & What It Does (Functions)

We look at acetylcholine and its many bodily functions. We explore why it is such an important neurotransmitter and neuromodulator and how an acetylcholine dysfunction can lead to serious health problems.

Acetylcholine is an important neurotransmitter and neuromodulator that is found in the central nervous system and the peripheral nervous system and helps with basic movement, cognitive function, learning, memory, and sleep.

As it plays such a vital role in key bodily functions, regulating levels is important and knowing what it is and its functions can help with this. This is why we have written this article, to tell you everything you need to know about acetylcholine!

What is Acetylcholine?


Acetylcholine is a neurotransmitter and neuromodulator found at neuromuscular junctions and synapses in the ganglia of the visceral motor system, as well as at a variety of sites inside the central nervous system.

As it is found in the central nervous system, this includes the brain and the spinal cord, as well as the peripheral nervous system. This is the network of nerves that are located outside the brain and the spinal cord.

Acetylcholine is found in all motor neurons. Here, it stimulates muscles to contract, and form the movements of the stomach and heart to a blinking eye, every action your body completes involves the actions of this vital neurotransmitter.

A neurotransmitter is a chemical messenger in the brain which allows your nerves to communicate with each other and all out other organs. Acetylcholine is the most common, abundant, and important neurotransmitter and is used throughout our entire nervous system. It is therefore very important to know the signs of low acetylcholine and how to fix this.

A part of the cholinergic system, it is an ester of choline and acetic acid and was first isolated in 1914. The chemical compound gets its name from this structure. Its role as a neurotransmitter was discovered by Henry Hallett Dale and confirmed by Otto Loewi.

Both Otto Loewi and Henry Hallett Dale were awarded the Nobel Prize in Physiology or Medicine in 1936 for their discovery in the field.

The neurotransmitter is known to play a vital role in cognitive function, memory, learning, information retention and is known to be inadequately available in Alzheimer’s disease. It can also support muscle contractions, helps with arousal and sleep, as well as facilitate and release other important brain chemicals such as dopamine and serotonin.

Acetylcholine is synthesized in nerve terminals in a reaction that is created by choline acetyltransferase. The presence of choline acetyltransferase in a neuron is a good indication that acetylcholine is used as one of its important transmitters.

Choline is present in plasma at a concentration of about 10 mM and is eaten by cholinergic neurons. Around 10, 000 molecules of acetylcholine are packed into each vesicle by a vascular acetylcholine transporter. Choline is a compound which you usually consume in eggs, beef liver, beans, nuts, and poultry.

The postsynaptic action of acetylcholine at cholinergic synapses is not terminated by reuptake. Instead, they are terminated by acetylcholinesterase. This enzyme is concentrated in the synaptic cleft which decreases the concentration of acetylcholine after it has been released from the presynaptic terminal. Acetylcholinesterase hydrolyzes acetylcholine into acetate and choline.

What are the Functions of Acetylcholine?

Acetylcholine serves many critical functions inside the body. A lot of these functions can be impaired by disease or drugs which influence the neurotransmitter’s function.

The main function of acetylcholine is that is a key neurotransmitter in the brain and helps to send signals to other cells. This includes neurons, muscle cells, and gland cells. Let’s take a look at these functions in closer detail:


Acetylcholine helps with muscle actions and stimulates skeletal muscles to contract. This means drugs that influence this neurotransmitter can cause movement disruption and sometimes paralysis.

Acetylcholine acts as a chemical that motor neurons in the nervous system release to activate muscles. It plays an important role in the somatic nervous system where it plays an excitatory role that leads to the voluntary activation of muscles.

In the autonomic system, acetylcholine controls several functions by acting on neurons in the sympathetic and parasympathetic systems. It also helps with a smooth contraction of muscles and the dilation of blood vessels.

As acetylcholine allows for skeletal muscle contractions, it makes it an essential neurotransmitter for movement and coordination.

Acetylcholine dysfunction can therefore result in extreme muscle weakness and trouble controlling voluntary movements. This can include the eyes and the face. In very extreme cases, paralysis and convulsions can occur alongside trouble breathing and heart failure.

Dilates Blood Vessels

Acetylcholine helps to regulate blood pressure. When blood flows through the body it creates friction. This can be seen in image signaling technology which focuses on the endothelium.

The endothelium is a cell barrier between your blood and the vessel wall.

A study on the main arteries in rats found this friction can trigger the release of acetylcholine and this leads to calcium being released by your endothelial cells, nitric oxide production, and artery relaxation.

Human clinical trials however still need to be carried out to fully understand how acetylcholine dilates blood cells in the human body.

Brain and the Central Nervous System

Acetylcholine functions in the central nervous system as a neurotransmitter and neuromodulator. As a result of this, it plays a major role in motivations, learning, arousal, and memory.

Acetylcholine supports executive functions related to cognitive processes. These relate to impulse control, attention span, planning, and decision-making.

When levels of acetylcholine in the body are disrupted, this might be associated with Alzheimer’s disease. Drugs and other substances which interrupt acetylcholine function can have negative side effects on the body and in the worst cases, can lead to death. Examples of these substances include certain pesticides and nerve gasses.

Research suggests acetylcholine can protect against age-related cognitive declines in memory. This includes decline which is associated with Alzheimer’s disease.

Acetylcholine also supports neuroplasticity. This is specifically found in the hippocampal and cortical regions. Neuroplasticity is the ability of the brain to form and reorganize synaptic connections that respond to individual experiences and learning.

Interesting Fact: The venom of a black widow spider interacts with levels of acetylcholine in the body. When a person is bitten by this type of spider, their levels increase which leads to severe muscle spasms, contractions, paralysis, and sometimes death.

Slows Down Heart Rate and Stimulates Secretions

Acetylcholine is the predominant neurotransmitter found in the parasympathetic nervous system. When your heartbeat is raised and reaches levels that are above normal, acetylcholine is released into your system and this is what slows your heart rate down until it goes back to baseline.

As acetylcholine works on cholinergic receptors to organ systems, it can stimulate body secretions by the glands that are receptive to nerve impulses. Examples of these glands include digestive glands, exocrine sweat glands, and salivary glands.

Health Benefits

These are the health benefits of acetylcholine.

Helps with Learning and Attention Span

Acetylcholine is vital for mental alertness, maintaining an attention span, and mediating any other changes in the brain. This includes the hippocampus and the forebrain and leads to learning, thinking skills, and memory formation.

It does this by affecting the way synapses send and receive feedback and this enhances different versions of ‘encoding’ in the variety of cortical structures in the brain.

Enhances Memory

Cholinergic signaling has been proven to link with memory and anti-inflammatory effects that create an impact on how the brain creates and stores these memories long-term. Research has been done into people with Alzheimer’s disease and how cholinesterase breaks down and destroys the acetylcholine in the body.

When acetylcholine is broken down, this leads to an acetylcholine dysfunction and can negatively impact cognitive function in a variety of different ways.

People with Alzheimer’s, therefore, have less acetylcholine in their brain, yet the medications used to treat the disease block the enzyme, cholinesterase, is what dismantles the acetylcholine. These medications include donepezil, galantamine, and rivastigmine.

Controls Arousal and Sleep

Acetylcholine functions as a neuromodulator as well as a neurotransmitter and because of this, it impacts the release of alternate calming and stimulating neurotransmitters. Acetylcholine is known to impact motivation, energy levels, and arousal.

It is also believed to play an important role in promoting REM sleep. REM sleep is a sleep cycle that is necessary for restoration, learning, and memory formation. As it can so heavily impact our sleep, this is why it is so important to help us feel alert throughout the day, both mentally and physically.

Acetylcholine Importance

As acetylcholine is such an important neurotransmitter and neuromodulator, problems quickly arise when pathways deteriorate. These problems affect cognitive functioning, motor control, overall mood, mental alertness, and memory.

Acetylcholine sends messages along with all your nerve cells and through the nervous system. This means all body movements depend on the compound and this communication and therefore disruption can result in serious illness too.

When nerves no longer receive the proper signals, muscle weakness could occur, the risk of developing Alzheimer’s disease increases, some might struggle to control voluntary movements and in serious cases, it might even lead to paralysis.

An interference with acetylcholine synthesis is usually brought on by toxins, drugs, or poison and these can have serious effects on different parts of the body. This is because it can affect not only the brain, but also the heart, nerves, and skeletal muscles.

Drugs that are known to affect acetylcholine levels include certain antibiotics such as clindamycin and polymyxin, anticonvulsants, magnesium, diuretics, and calcium channel blockers.

Moreover, if there are issues with cholinergic nerve receptors or the appropriate release and uptake of acetylcholine, abnormal muscle function can occur and you might need to source anticholinergic drugs.

Anticholinergics can also treat urinary incontinence or an overactive bladder, asthma and respiratory disorders, symptoms of Parkinson’s disease, gastrointestinal issues such as diarrhea, and poisoning from toxins.

The drugs can block acetylcholine’s blinding action and impact parasympathetic nerve impulses. They have also helped with cognitive slowing effects and should be avoided by those over 70 years old due to the risk of hallucination or confusion.

Fortunately, acetylcholine receptors can be targeted with medications that adjust how your body functions in a disease state caused by acetylcholine dysfunction.

Acetylcholine Boosters

Replenishing the acetylcholine in your body can be done by using nootropics and dietary supplements. We recommend Optimal Choline Complex as the best way to replenish acetylcholine which can be found on the link below:

Optimal Choline Complex can stimulate acetylcholine production as well as support cognitive function and mood and stress response. It’s also neuroprotective and promises to balance out and optimize essential neurotransmitter levels with other vital brain functions.

Optimal Choline Complex was designed to create a complete acetylcholine replenishment system and can improve memory and mood whilst reducing anxiety and brain fog alongside this.

The choline supplement is natural and suitable for vegans. It also uses the purest forms of choline in the formula. The formula uses a multi-faceted approach to maximize acetylcholine production.

Other common nootropics which are commonly used to create more acetylcholine are Alpha GCP, CDP (choline and choline bitartrate), Bacopa Monnieri, Huperzine A, and Ginkgo Biloba.

Frequently Asked Questions

Your questions answered.

What Foods Contain Acetylcholine?

There aren’t any foods that contain pure acetylcholine but foods that include choline are beef liver and grass-fed beef, poultry, eggs, chickpeas, beans, goat milk, fish, and vegetables such as broccoli or cauliflower. Eating enough of these foods can help with the synthesis of acetylcholine.

How Do You Lower Levels of Acetylcholine?

Prescription anticholinergic medications can lower these levels but the right drug depends on the body system. This means asthmatic conditions or respiratory conditions similar to this will be treated differently to acetylcholine imbalance that is associated with brain conditions.

What Enzyme Breaks Down Acetylcholine?

Acetylcholinesterase is the enzyme that turns acetylcholine into acetic acid and choline. It is a cholinergic enzyme and is found at postsynaptic neuromuscular junctions in the nerves and muscles.

What Causes Too Little Acetylcholine?

Some common causes of low levels of acetylcholine include genetic errors, chronic illness, medications, chronic inflammation, and aging. Diagnosis can be difficult as there aren’t any blood tests available and is usually based on a clinical diagnosis instead.


Acetylcholine is a neurotransmitter that plays a critical role in many bodily functions. It helps with the normal function of both the brain and body and this means if levels are interrupted, it can result in serious problems with movement, coordination, and memory.

The neurotransmitter is known to play an important role in cognitive function and is known to be inadequately available in people with Alzheimer’s disease. It can support muscle contractions, support a healthy sleep cycle, as well as release other important brain chemicals such as dopamine and serotonin, to help you feel mentally alert.

We hope by reading this article you understand the neurotransmitter and neuromodulator in a little more detail and know why it’s so important to normal body functioning. If you want to boost your acetylcholine levels, don’t be afraid to try the nootropics or dietary supplements we have suggested.