I think since the day I started my nutrition degree, I had always been fascinated by the brain, but I never really knew why.
This all changed when I was introduced to the world of antidepressants, something that came into regular use to cope with my alcohol addiction.
See, I never knew much about antidepressants, and the extent of my knowledge at this point with neurotransmitters was pretty basic.
Fast forward to late 2017, I came across a fantastic little book called Brain in Balance, Understanding The Genetics And Neurochemistry Behind Addiction And Sobriety.
This book was a gold mine at really simplifying the science of neurochemistry and it related to addiction and got me deep in the weeds of how substance abuse impacts our neurochemical state.
What are Neurotransmitters?
Neurotransmitters are chemical signals that are used by our nervous system to transmit signals between these things known as neurons (or nerve cells).
We have billions of these neurons, about 86 billion actually.
Our body could be considered a big battery, using these neurons to send electrochemical signals across the body.
These neurotransmitters are broken up into eight different types that you may have heard of, including serotonin and dopamine.
Let’s discuss the roles, uses, and primary functions of these eight neurotransmitters.
Probably one of the most common and well-known neurotransmitters, quite often associated with mood, and is commonly prescribed for depression.
We have about 15 receptors of serotonin throughout the body known as 5-HT receptors, and I often like to describe these receptors as switches on a switchboard.
Some of these switches are on; some are off, making it a little bit harder to determine the true optimal serotonin level of every individual.
Often at times, people are pre-disposed on a genetic level to naturally have low baseline levels of serotonin, making them more susceptible to depression (Nordquist & Oreland, 2010).
Serotonin Primary Functions
Appetite control, mood, regulation of arousal state, and sensory perception including pain
Depression-worse during winter, Anxiety / Social anxiety, Aggression, OCD tendencies, Carbohydrate cravings, Frequent constipation, Low pain intolerance, Poor dream recall, Insomnia, Impulsive tendencies, Low self-esteem.
Confusion, Extreme agitation, Muscle twitching, Gastrointestinal distress, Nausea.
If you have low Serotonin production
Something as simple as a good Vitamin D supplement can help with this.
Next on the list is dopamine, another well-known neurotransmitter most commonly recognised for its role in pleasure and reward-seeking behaviour.
Dopamine is also referred to as the molecule of more, which is an absolute spot-on way to describe it.
When we get a euphoric high from drugs such as cocaine, that feel-good craving or wanting is attributed to dopamine.
It’s also why sugar addiction is real, because sugar triggers that release of dopamine, and has us wanting more.
The downside of dopamine is that when we partake chronically in sugary beverages, alcohol, and drug use, we downregulate our dopamine receptors, which downregulates dopamine production (Volkow et al., 2010).
When this happens, our day-to-day motivation and drive can become dampened, we can feel a little flat, depressed, and make more impulsive decisions.
Dopamine Primary Functions
Motivation, drive, and reward system including states of pleasure and euphoria. It also is involved in fine-tuning motor function, and states of perseveration.
Addictive tendencies, Tremors/restless legs, Low libido, Lacking motivation, Depression, Mental exhaustion, Dull, boring dreams, Forgetfulness.
If you have low Dopamine production
GABA (Gamma-aminobutyric acid)
GABA is the calming force that resides in our body, a neurotransmitter commonly involved in slowing neuronal activity.
It creates calm, relaxation, stimulates the part of the nervous system that allows us to rest and digest, and balances our other neurotransmitters associated with agitation (Glutamate, noradrenaline).
When we are low in GABA, we tend to move fast, talk more rapidly and feel a little over-stimulated, sometimes even anxious.
GABA Primary Functions
Main inhibitory neurotransmitter. Involved in calm, relaxation, sleep, and sleep maintenance.
Unlikely to happen
If you have low GABA production
Glutamate is the opposite of GABA, best described as one of the agitating, excitatory neurotransmitters of the body, so much it can excite neurons to death.
GABA works synergistically with this system to keep it balanced.
When we’re irritable, or radiating with overwhelming anxiety, glutamate is often to blame.
Rapid raises in glutamate are extremely common in the post substance abuse, withdrawal state of alcoholics.
This is usually why you’re more nervous, shaky, and often irritated following the days after drinking alcohol.
It’s this reason why medical supervision is often required when someone is withdrawing from days of chronic alcohol abuse because glutamate can get so high, It can result in seizures.
Chronic dysregulation of glutamate can often result in memory and learning impairment, and lead to long-term cognitive complications (Lewerenz & Maher, 2015).
Glutamate Primary Functions
Main excitatory neurotransmitter. Important in attention, focus, concentration, and memory, motor, and executive function.
Unlikely to happen.
Agitation, Poor memory, Poor focus, Poor concentration, Anxious.
If you have high Glutamate production
Look at raising your GABA Levels.
The opiate system is a less common one and is commonly known for its ability to produce a chemical found in the body known as endorphins.
These are the body’s natural form of morphine, which is often found coursing through our veins after a long run or rigorous exercise session.
Opioid receptors are found throughout our nervous system and gastrointestinal tract and serve some unique functions including pain, mood, and gastrointestinal function (Feng et al., 2012).
When our opiate system is activated, it also sets off a chain reaction, stimulating the release of GABA and the wanting nature of dopamine.
In substance abuse, the extreme feelings of pleasure and euphoria can be attributed to this system, and it’s extremely potent.
This window of pleasure is what drives alcoholics to keep drinking, also known as blackout drinkers because this window of euphoric pleasure is quite narrow and any further leaves individuals passed out or unconscious.
Opioid Primary Functions
Release & regulation of dopamine. Inhibit excitatory pathways. Reduction in pain. Reward reinforcement & euphoria.
Low pain tolerance, Addictive tendencies, Carbohydrate cravings, Feelings of anxiety and tension, Depression, Dwelling of major life situations.
Unlikely to happen.
If you have low Opioid production
Noradrenaline is a catecholamine-like neurotransmitter responsible for the body’s fight-or-flight stress response system.
Stimulant drugs such as cocaine or amphetamines tend to work on these noradrenaline receptors, which creates an intense euphoric high, heightened alertness, and high amounts of seemingly limitless energy.
Noradrenaline tends to bind to various receptors across the body when our stress response is triggered, helping us to contract various muscles, deliver fast nutrients across the body and dilate blood vessels and airway passages (Zhang et al., 2013).
Interestingly, we need adequate dopamine levels to produce noradrenaline, so if our noradrenaline is out of balance, dopamine could be the reason.
It’s believed that stimulant-like drugs are linked to the adrenaline-esque rush we get from noradrenaline release, and anti-alcoholism drugs such as Disulfiram (Antabuse) have been used in an attempt to block these receptors and close the addictive loop (Sofuoglu & Sewell, 2009).
Noradrenaline Primary Functions
Fight-or-flight response – sympathetic nervous system. Increase in heart rate & dilates air passages. Modulate dopamine and serotonin. Arousal and REM Sleep. Concentration and memory formation.
Chronic stress, fatigue and pain. Depression, Hypotension, Hypoglycaemia, Exhaustion, Short attention span, Low pain tolerance.
States of panic, Panic attacks.
If you have low Noradrenaline production
Look at raising your Dopamine levels
Our second last neurotransmitter system is our endocannabinoid system, and to no surprise, it’s closely tied with our sensation of appetite,
This is the system that gets activated in marijuana users, and can often result in extreme hunger, also known as “the munchies”.
The endocannabinoid system is broken into two receptor types, CB1 and CB2.
CB1 is found in high concentrations of the brain in areas that control our emotion, memory, mood sensory perception and so fourth.
CB2 is found primarily in immune cell tissue, and is associated with immune system activation and may also assist in sleep.
Interestingly, the activation of CB2 receptors has been shown to reduce self-administration in chronic drug users (Zou & Kumar, 2018), and activation of both receptors may assist in conditions of depression or chronic pain (Huang et al., 2016).
CB1 activation may also help to reduce glutamate levels, something quite high in chronic alcohol abuse and alcohol withdrawal.
Endocannabinoid Primary Functions
Regulation of feeding behaviour, Appetite, Energy metabolism, Learning & memory, Pain and inflammation
Low pain tolerance, Excessive inflammation, treatment-resistant conditions
Excessive food intake and increased obesity risk
If you have low Endocannabinoid production
A good Omega-3 Fish Oil supplement is a great place to start here.
Our last neurotransmitter is acetylcholine, vital for memory formation, memory recall, and keeping our attention span sharp.
Individuals who have a cigarette smoking addiction tie in with this one, as nicotine has an activating effect on acetylcholine receptors (Brunzell et al., 2015).
There has even been research to show that, when used correctly; small amounts of nicotine may actually improve cognitive function and focus due to this activation.
The acetylcholine system is also closely tied with dopamine, meaning when we drink booze and smoke, we create a significant surge in dopamine release (Tarren et al., 2016).
Acetylcholine Primary Functions
The parasympathetic nervous system, Memory, learning, attention span, REM Sleep, Gastric secretion, digestive enzymes, Peristalsis.
Sympathetic dominance, Short-term memory problems, Age-related cognitive decline, Impaired digestive function, Light Sleeper, Poor sleep onset, Tension in muscles.
Unlikely to happen.
If you have low Acetylcholine production
A simple Acetyl-l-carnitine supplement is a fantastic place to start
Hopefully I’ve given you a fairly succinct and overall understanding of the many neurotransmitters found in our bodies.
If you’d like to learn more, I actually write more extensively on these in my upcoming book Hacking Your Addiction, in which I also expand on more functions, deficiency causes, and more compounds that can assist with raising our levels.
If you have any feedback regarding this article, reach out. Help Clarity reach more people and quit addiction by following us on Instagram, it’s also the perfect place to message us and ask questions!
- Brunzell, D. H., Stafford, A. M., & Dixon, C. I. (2015). Nicotinic receptor contributions to smoking: Insights from human studies and animal models. Current Addiction Reports, 2(1), 33-46. https://doi.org/10.1007/s40429-015-0042-2
- Feng, Y., He, X., Yang, Y., Chao, D., H. Lazarus, L., & Xia, Y. (2012). Current research on opioid receptor function. Current Drug Targets, 13(2), 230-246. https://doi.org/10.2174/138945012799201612
- Gauthier, I., & Nuss, P. (2015). Anxiety disorders and GABA neurotransmission: A disturbance of modulation. Neuropsychiatric Disease and Treatment, 165. https://doi.org/10.2147/ndt.s58841
- Huang, W., Chen, W., & Zhang, X. (2016). Endocannabinoid system: Role in depression, reward and pain control (Review). Molecular Medicine Reports, 14(4), 2899-2903. https://doi.org/10.3892/mmr.2016.5585
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- Nordquist, N., & Oreland, L. (2010). Serotonin, genetic variability, behaviour, and psychiatric disorders – a review. Upsala Journal of Medical Sciences, 115(1), 2-10. https://doi.org/10.3109/03009730903573246
- Prentice, H., Modi, J. P., & Wu, J. (2015). Mechanisms of neuronal protection against Excitotoxicity, endoplasmic Reticulum stress, and mitochondrial dysfunction in stroke and neurodegenerative diseases. Oxidative Medicine and Cellular Longevity, 2015, 1-7. https://doi.org/10.1155/2015/964518
- Sofuoglu, M., & Sewell, R. A. (2009). Norepinephrine and stimulant addiction. Addiction Biology, 14(2), 119-129. https://doi.org/10.1111/j.1369-1600.2008.00138.x
- Tarren, J., Shariff, M., Holgate, J., & Bartlett, S. E. (2016). Effects of alcohol on nicotinic acetylcholine receptors and impact on addiction. Neuropathology of Drug Addictions and Substance Misuse, 411-419. https://doi.org/10.1016/b978-0-12-800213-1.00038-9
- Volkow, N. D., Wang, G., Fowler, J. S., Tomasi, D., Telang, F., & Baler, R. (2010). Addiction: Decreased reward sensitivity and increased expectation sensitivity conspire to overwhelm the brain’s control circuit. BioEssays, 32(9), 748-755. https://doi.org/10.1002/bies.201000042
- Zhang, G., Gao, Z., Guan, S., Zhu, Y., & Wang, J. (2013). Upregulation of excitatory neurons and downregulation of inhibitory neurons in barrel cortex are associated with loss of whisker inputs. Molecular Brain, 6(1). https://doi.org/10.1186/1756-6606-6-2
- Zou, S., & Kumar, U. (2018). Cannabinoid receptors and the Endocannabinoid system: Signaling and function in the central nervous system. International Journal of Molecular Sciences, 19(3), 833. https://doi.org/10.3390/ijms19030833
Former drinker, Nutritionist, Biohacking enthusiast, self-experimenter, research fanatic, and self-taught writer, Stephen immerses himself deep into the literature of human optimisation and better understand the nature of addiction. His goal is to help people take control of their addiction, reset their cravings, unscramble their broken brain circuitry and use actionable strategies that work ten times better than anything else.