The different types of neurotransmitters: What are they?

 

You’ve probably heard of how dopamine plays a role in feelings of pleasure, or how serotonin levels influence depression. This barely scratches the surface when talking about the different types of neurotransmitters. Not only do they influence our mood, they also influence how our heart beats, how our lungs breathe, and how our stomach digests everything. Here’s a crash course on all the neurotransmitters you need to know.    

Understanding the different types of neurotransmitters

Understanding the different types of neurotransmitters

Test your knowledge

How much do you know about neurotransmitters? Take the quiz to find out!

1. Which neurotransmitter has 5 different receptors for it?
2. Which neurotransmitter is also called 5-hydroxytryptamine, or 5-HT for short?
3. Which of the following neurotransmitters are inhibitory?
4. The area in which neurotransmitters are released from one cell to communicate with the other is called the _____
5. When there is a neurochemical imbalance causing an issue or illness, scientists can develop drugs that help to balance it. What is a major consideration when developing drugs that influence brain chemistry?

Types of neurotransmitters – How they work

Before we can learn about the different types of neurotransmitters, we need to understand what neurotransmitters are, and how they work.

Neurotransmitters are chemicals that are released from nerve cells to other target cells to communicate information.

Neurons can communicate using both electrical and chemical methods. Tiny packages called vesicles are hidden within the synaptic terminal (get to know your brain) of each neuron. These vesicles contain the neurotransmitters that are released when stimulated by an electrical impulse, called an action potential. Once these packages are given a signal to open, they travel to the cell’s membrane and release the neurotransmitters into the synapse. The synapse is a gap between the dendrites of one neuron and the axon terminal of another neuron.

Neurotransmitters interact with receptors on the dendrites of the other neuron, much like how a lock and key work. The neurotransmitters have specific shapes that fit into a receptor that can accommodate that shape. Once the neurotransmitter and the receptor are connected, the neurotransmitter sends information to the next neuron to either fire an action potential, or to inhibit firing. If the neuron gets the signal to fire, then the whole process starts over again.

Types of neurotransmitters

It would be very long and complicated to tell you about every neurotransmitter in the brain and what it is responsible for. So instead, let’s take a look at some of the major types of neurotransmitters and what they do.

Types of neurotransmitters: Dopamine

Dopamine can play a lot of different roles in the brain, depending on the location. In the frontal cortex, dopamine acts as a traffic officer by controlling the flow of information to other areas of the brain. It also plays a role in attention, problem-solving, and memory. And you’ve probably heard how dopamine plays a role in things that give us pleasure. So if you were to eat a piece of chocolate, dopamine would be released in some areas of the brain, allowing you to feel enjoyment, motivating you to eat more chocolate.

Types of neurotransmitters: Serotonin

Serotonin is known as an inhibitory neurotransmitter, meaning that it doesn’t give the next neuron the signal to fire. Serotonin is involved with mood, as well as your sleep cycle (click here to find out how to become a morning person!), pain control, and digestion. In fact, the majority of serotonin in the body can be found in the gastrointestinal tract, and only about 10% is actually found in the brain. Aside from aiding in digestion, serotonin can also help with forming blood clots and increasing sex drive.

Types of neurotransmitters: Acetylcholine

Acetylcholine (ACh) plays a major role in the formation of memories, verbal and logical reasoning, and concentration. ACh has also shown to help with synaptogenesis or the production of new and healthy synapses throughout the brain. Acetylcholine actually comes from the chemical known as choline, which can be found in foods such as eggs, seafood, and nuts.

Acetylcholine also plays a major role in the movement. A nerve cell can release ACh into a neuromuscular junction, which is a synaptic connection between a muscle fiber and a nerve cell. When ACh is released, it causes a series of mechanical and chemical reactions that result in the contraction of muscles. When there is a lack of ACh in the neuromuscular junction, the reactions stop and the muscle relaxes.

Types of neurotransmitters: GABA

GABA is also an inhibitory neurotransmitter that helps to balance any neurons that might be over-firing. This becomes especially helpful when it comes to anxiety or fear because the release of GABA helps to calm you down. In fact, caffeine actually works to inhibit GABA from being released, so that there is more stimulation in the brain.

GABA also plays a role in vision and motor control. Some drugs work to increase the levels of GABA in the brain. This helps with epilepsy and helps to treat the trembling found in patients with Huntington’s disease.

Types of neurotransmitters: Noradrenaline (norepinephrine)

These might sound like two big and confusing words because you’ve probably heard about adrenaline (epinephrine) before. Before we go any further, let’s define these terms.

Another name for adrenaline is epinephrine. Epinephrine is a hormone that is secreted by the adrenal gland, which is a gland that rests on top of the kidneys. Hormones are molecules that are released into the bloodstream.

Noradrenaline is also known as norepinephrine. Norepinephrine is a neurotransmitter, meaning that its used for interactions between neurons.

Noradrenaline is an excitatory neurotransmitter that helps to activate the sympathetic nervous system, which is your “fight or flight” response to a stressor. Norepinephrine also plays a role in attention, emotion, sleeping and dreaming, and learning. When it is released into the bloodstreams, it helps to increase heart rate, release glucose energy stores, and increase blood flow to the muscles.

Types of neurotransmitters – When neurotransmitters go wrong

When the neurotransmitters are balanced, it helps us to lead healthy and balanced lives. But sometimes the environment or our genes can trigger imbalances in these essential chemicals, causing illnesses such as depression, Parkinson’s disease, and schizophrenia to arise (see more about brain gym exercises for these diseases).

Types of neurotransmitters: Depression

There are many known causes of depression, with one of them being the amount of serotonin in the brain. Studies have shown that decreases in the production of serotonin in the brain can lead to feelings of depression. In some cases, low serotonin levels can actually lead to suicidal thoughts. Other studies link lower levels of norepinephrine to depression. These studies suggest that the low levels of serotonin are actually triggering the norepinephrine levels to be low, causing a depressed mood. (Are antidepressants for you?)

Types of Neurotransmitters

Types of neurotransmitters: Parkinson’s Disease

Parkinson’s Disease (PD) is a neurodegenerative disorder that affects the neurons responsible for movement in the body. Since dopamine is responsible for transmitting information about movement, the death of these neurons can cause symptoms such as tremor, stiffness, or balance issues. The body tries to compensate for the lack of dopamine by releasing more glutamate, which is a neurotransmitter that has a role in learning and memory. However, glutamate is an excitatory neurotransmitter, and having too much glutamate can lead to the overexcitement and eventual death of neurons. Treatments for PD include L-Dopa, which is a precursor to dopamine that can cross the blood-brain barrier and relieve movement problems.

Parkinson

 

Types of neurotransmitters: Schizophrenia

Schizophrenia is a disabling disorder that impacts how a person thinks, feels, and acts. Research shows that some imbalances in dopamine might play a role. The “dopamine hypothesis” states that having too much dopamine in the brain can cause schizophrenia. This idea led to antipsychotic medications that aim to lower the amount of dopamine released in the brain and reduce the symptoms of schizophrenia. But there are other small changes in the brain that may contribute to schizophrenia. For example, the ventricles, or areas of the brain filled with cerebrospinal fluid (CSF), are larger in patients with schizophrenia.  However, these differences are not significant enough to generalize for all people with schizophrenia. Read here for more information on how to reduce the symptoms of schizophrenia.

Depression can be linked to neurotransmitter imbalances

Depression can be linked to neurotransmitter imbalances

Jessica is a student studying neuroscience and psychology. She is fascinated with all things people, from the way our brains work to how we think. She is always looking for new things to learn, and is eager to help others be inspired.