Neurotransmitters play an important role in neural communication. They are chemical messengers that carry messages between nerve cells (neurons) and other cells in your body, influencing everything from mood to involuntary movements. This process is generally referred to as neurotransmission or synaptic transmission.
Specifically, excitatory neurotransmitters have excitatory effects on the neuron. This means they increase the likelihood that the neuron will fire a signal called an action potential in the receiving neuron.
Neurotransmitters can act in predictable ways, but they can be affected by drugs, disease, and interaction with other chemical messengers.
To send messages throughout the body, neurons need to transmit signals to communicate with one another. But there is no physical connection with each other, just a minuscule gap. This junction between two nerve cells is called a synapse.
To communicate with the next cell, a neuron sends a signal across the synapse by diffusion of a neurotransmitter.
Neurotransmitters affect neurons in one of three ways: they can be excitatory, inhibitory, or modulatory. An excitatory transmitter generates a signal called an action potential in the receiving neuron. An inhibitory transmitter prevents it. Neuromodulators regulate groups of neurons.
- Excitatory neurotransmitters have excitatory effects on the neuron. This means they increase the likelihood that the neuron will fire an action potential.
- Inhibitory neurotransmitters have inhibitory effects on the neuron. This means they decrease the likelihood that the neuron will fire an action.
- Modulatory neurotransmitters can affect a number of neurons at the same time and influence the effects of other chemical messengers.
Some neurotransmitters, such as dopamine, depending on the receptors present, create both excitatory and inhibitory effects.
The most common and clearly understood types of excitatory neurotransmitters include:
This is an excitatory neurotransmitter that is found throughout the nervous system. One of its many functions is muscle stimulation, including those of the gastrointestinal system and the autonomic nervous system.
Are you familiar with cosmetic Botox injections? They’re used to eliminate wrinkles by temporarily paralyzing certain muscles. This procedure uses botulinum toxin to freeze the muscles in place by preventing neurons in the area from releasing acetylcholine.
Also called adrenaline, epinephrine is an excitatory neurotransmitter produced by the adrenal glands. It is released into the bloodstream to prepare your body for dangerous situations by increasing your heart rate, blood pressure, and glucose production.
Are you familiar with the fight-or-flight response? Adrenaline helps your nervous and endocrine systems prepare for extreme situations in which you might be making a fight-or-flight decision.
This is the most common neurotransmitter in the central nervous system. It is an excitatory neurotransmitter and usually ensures balance with the effects of gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter.
Dopamine has effects that are both excitatory and inhibitory. It is associated with reward mechanisms in the brain.
Drugs such as cocaine, heroin, and alcohol can temporarily increase its levels in the blood. This increase can lead to nerve cells firing abnormally that can result in intoxication along with consciousness and focus issues.
A typical secretion of dopamine in your bloodstream can contribute to motivation.
Also called noradrenaline, norepinephrine is the primary neurotransmitter in the sympathetic nervous system where it works to control heart rate, blood pressure, liver function, and other functions.
Also known as GABA, gamma-aminobutyric acid is an inhibitory neurotransmitter that acts as a brake to the excitatory neurotransmitters. GABA has wide distribution in the brain and has a major role in reducing neuronal excitability throughout the nervous system.
Serotonin is an inhibitory neurotransmitter that is involved in emotion and mood, balancing excessive excitatory neurotransmitter effects in your brain. Serotonin also regulates processes, such as sleep cycle, carbohydrate cravings, food digestion, and pain control.
Many neurotransmitters have been associated with a number of disorders.
- Alzheimer’s disease has been linked to a lack of acetylcholine and glutamate in certain regions of the brain.
- Schizophrenia has been linked to excessive amounts of dopamine in the mesolimbic pathway of the brain.
- Parkinson’s disease has been linked to too little dopamine in the brain’s motor areas.
- Epilepsy and Huntington’s disease have been linked to lowered GABA in the brain.
- Mood disorders such as anxiety have been linked to low levels of serotonin.
- Mood disorders such as manic depression, anxiety, and impaired sleep cycle have been linked to noradrenaline (norepinephrine) and other neurotransmitters.
There are billions of neurotransmitter molecules working constantly to keep your brain functioning and managing everything from your breathing to your heartbeat to your ability to concentrate.
Understanding the way that nerve cells communicate, as well as how increases and decreases in neurotransmitters affect our physical and mental well-being, helps researchers and doctors find ways to make us happier and healthier.