If you’re familiar with nootropics supplements — supplements that are capable of helping increase alertness, attention, learning and memory — then you may have come across the compound called acetylcholine (or ACh). What is acetylcholine exactly?
As one of the most abundant and important neurotransmitters (or chemical messengers) in the body, acetylcholine plays a role in helping us focus, learn and memorize information. It’s also needed to support muscle contractions, help with arousal and sleep, and facilitate the release of other important chemicals, such as dopamine and serotonin.
While acetylcholine supplements are not available (similarly to how you can’t take dopamine supplements), there are certain nutrients you can take in supplement form to boost synthesis of ACh, as well as foods to include more of in your diet.
What Is Acetylcholine?
Acetylcholine (ACh) is a neurotransmitter and neuromodulator. This means it works by sending signals between nerves.
It’s made up of acetic acid and choline and is a part of the cholinergic system.
ACh is most well-known for supporting cognitive function, especially memory and attention. It was actually one of the first neurotransmitter scientists discovered.
Where is acetylcholine found? In humans it’s found in the central nervous system, which includes the brain and spinal cord, and the peripheral nervous system, which is the network of nerves located outside the brain and spinal cord.
Like other neurotransmitters (or chemicals that are released by neurons to send signals to other neurons), ACh is specifically found between nerve synapses (gaps between nerve cells).
Acetylcholine is synthesized in nerve terminals from acetyl coenzyme A (which comes from a form of glucose) and choline. Choline is a compound that you consume when you eat eggs, beef liver, poultry and some beans and nuts.
The more you consume of it, the easier it is for you body to produce enough acetylcholine.
How It Functions in the Body
What is the main role of acetylcholine? As a key neurotransmitter, it helps send signals to other cells, including neurons, muscle cells and gland cells.
It also modulates the release of other neurotransmitters, including dopamine, norepinephrine, and serotonin.
The network of nerve cells that use the neurotransmitter acetylcholine is referred to as the cholinergic system.
Some of the functions that acetylcholine has include:
Stimulating skeletal muscles to contract.
Inhibiting activation of the cholinergic system.
Supporting neuroplasticity, specifically in the hippocampal and cortical regions. Neuroplasticity is defined as “the ability of the brain to form and reorganize synaptic connections in response to learning or experience.”
Protecting against age-related declines in memory, including decline associated with Alzheimer’s disease.
Supporting “executive functions,” which are considered higher-order cognitive processes. These processes are related to impulse control, planning, attention, decision-making and so on.
Helping to guide vision-related attention.
Regulating motivation, arousal and certain stages of sleep.
1. Helps with Learning and Attention
Studies show that ACh is important for alertness, sustaining attention and mediating changes in the brain (including in the hippocampus and forebrain) that lead to learning and memory formation. One way it does this is by affecting the way that synapses send and receive feedback, enhancing different types of “encoding” in different cortical structures of the brain.
2. Supports Memory
Emerging evidence also links cholinergic signaling with improved memory and even anti-inflammatory effects that impact how the brain creates and stores memories.
Research suggests that in people with Alzheimer’s disease, cholinesterase breaks down and destroys acetylcholine, leading to ACh dysfunction, which negatively impacts cognitive function in a number of ways.
According to Harvard Health Publishing:
the brains of people with Alzheimer’s disease have lower levels of acetylcholine than people without the disease, and the medications used to treat the early stages of the disease — donepezil (Aricept), galantamine (Reminyl), and rivastigmine (Exelon) — work by blocking an enzyme, cholinesterase, that dismantles acetylcholine.
3. Facilitates Muscle Contractions
ACh acts as a chemical that motor neurons in the nervous system release in order to activate muscles. At neuromuscular junctions, it allows for skeletal muscle contractions, which is essential for many functions, such as movement and coordination.
It can help promote contractions of smooth muscles, dilation of blood vessels, increased body secretions and a slower heart rate.