You have probably at one time heard of the role dopamine plays in feelings of pleasure or how serotonin influences depression. These are just but a few of the many roles neurotransmitters play in the body. Not only do they influence our mood, but they are responsible for regulating passive processes like digestion, breathing, and how our heart beats but also form the basis of higher cognitive processes like thinking and memory.
In this article, I will be giving an introduction into these chemical messengers, including what they are and their functions in the body.
WHAT EXACTLY ARE NEUROTRANSMITTERS?
Neurotransmitters are chemical messengers that convey, boost, and balance signals being transmitted between neurons, or nerve cells, and other body cells. These chemical messengers can influence a lot of functions in our body – both psychological and physical, including sleep, heart rate, mood, appetite, cognition, love and fear.
In order to ensure the proper functioning of our brain, billions of neurotransmitter molecules are constantly working to help manage everything from our heartbeat to our breathing to our learning and concentration levels.
HOW DO THEY WORK?
For neurons to send messages throughout the body, there is a need for them to be able to communicate with one another and transmit signals. Neurons form a web of connections in the brain and the body and at each of these connections is a synapse. The synapse is a specialised cell that allows communication between neurons. This process where the synapse is bridged so that signals can cross between neurons is called neurotransmission and what makes this possible are chemicals called neurotransmitters.
When an electric signal gets to the end of a neuron, it stimulates the vesicle which is a small sac containing the neurotransmitters. The vesicle pours its content into the synapse where it becomes easy for the neurotransmitters to bind and trigger changes in the cells. After the neurotransmitters are released, they cross the synaptic gap and attach the receptor on the other neuron. Depending on what the neurotransmitter is, it could either be inhibiting or exciting the receiving neuron.
Neuron utilizing dopamine to send signal across synapse, note the tyrosine hydroxylase to L-Dopa to Dopamine
THEY ARE CLASSED INTO THREE GROUPS
Neurotransmitters are majorly classified into 3 groups based on their function. They are classified as either excitatory neurotransmitters, inhibitory neurotransmitters, or modulatory neurotransmitters. The excitatory neurotransmitters produce an excitatory or stimulating effect on the receiving neuron – which means they increase the likelihood that the neuron will fire an action potential and the inhibitory neurotransmitters have inhibitory effects on the neurons meaning neurons are less likely to fire. There are also some neurotransmitters that can produce both an inhibitory and excitatory effect depending on the type of receptors on the receiving neurons.
Modulatory neurotransmitters, which are often referred to as neuromodulators are the category of neurotransmitters capable of affecting a larger number of neurons at the same time. Though they can be slow-acting, they also have the ability to influence the effects of other chemical messengers.
IMPORTANT NEUROTRANSMITTERS AND THEIR FUNCTIONS
Since 1921 when the first neurotransmitter was first discovered, about 50 more neurotransmitters have been discovered. The details of the actions of all these chemical signalers could fill books, but I’ll give a top level overview of the functions of some of the primary transmitters.
Acetylcholine was the first neurotransmitter to be discovered. It was first isolated in 1921 by the German biologist, Otto Loewi who latter won a Nobel Prize for his work. Acetylcholine is produced in the body from choline, a nutrient that can be found in foods like seafood, eggs, and nuts.
This neurotransmitter is responsible for stimulating muscles. It gets the motor neurons controlling the skeletal muscles activated. Acetylcholine also regulates the activities in some parts of the brain, which are associated with learning, attention, arousal, and memory.
People suffering from Alzheimer’s disease are usually found to be low in Acetylcholine levels. Many poisons like curare, botulin, and hemlock act by blocking the acetylcholine receptors.
Dopamine is considered to be a special type of neurotransmitter because its effects are both inhibitory and excitatory. It controls voluntary movements of the body, and it’s strongly associated with the reward mechanism of the brain meaning it is linked to the ability to motivate yourself. Dopamine is also used to be alert and vigilant, it is vital neurotransmitter required for day to day function and the ability to work. Low levels of dopamine is also associated with social anxiety and Parkinson’s disease, while excess dopamine can be linked to schizophrenia and stress. Dopamine itself is not found in many foods but most complex protein contains tyrosine or phenylalanine from which it is derived in the body.
#3: Gamma-aminobutyric acid (GABA)
However, excessive levels of glutamate also have a toxic effect on the nerve cells and may lead to conditions like stroke. Glutamate is naturally abundant and found in foods like tomatoes, cheeses, mushrooms, seaweeds, and soy.
NOOTROPICS AND THEIR ACTIONS IN THE BODY
- Increase neurotransmitter production: Nootropics have a powerful effect on the brain because they alter the regulation of neurotransmitters. Some of them also increase production rate of neurotransmitters in the brain. For instance, some herbs like bacopa and Rhodiola can stimulate the body to produce more neurotransmitters.
- Decrease neurotransmitter reuptake: nootropics also acts by directly decreasing reuptake of some nutrients like mono-amines as it is seen in Modafinil, Rhodiola, and anti-depressants. By decreasing the reuptake of the neurotransmitter in the brain the chemical acts to increase or regulate the level of neurotransmitter in the recipients brain.
- Replace precursor nutrients: Neurotransmitters require the presence of the precursor nutrients in the brain. Replenishing the precursor nutrients allows the brain to operate effectively where otherwise performance may suffer. The primary action of WorkWize is to replace the catecholamine precursors tyrosine and phenylalanine to help fight fatigue.
- Support brain growth: Some nootropics help increase growth-supporting factors in the brain, such as brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF). These two factors are important in regulating the growth and function of brain cells.
- Neuroprotective: Nootropics can have neuroprotective properties that help ward away age-related cognitive decline and keep your brain healthy even into your later years.
- Enhance blood flow: Some nootropics supports the flow of blood throughout the brain, helping you stay sharp and alert. It also supplies your brain with oxygen and other vital nutrients to help fight disease and mental fatigue.
- Anti-inflammatory: Some nootropics contain powerful antioxidants which help reduce inflammation in the brain. Reducing inflammation in the brain reduces the likelihood of various diseases including cancer.