Nicotine is a stimulating drug that is found in tobacco products including cigarettes, cigars, and pipe tobacco to name a few. It is a highly addictive component and is considered to be as addictive as heroin or cocaine. On inhaling nicotine, it takes a few seconds for the drug to reach your brain and a few minutes to get into your bloodstream. Some of the immediate effects of nicotine in your body include an increased heart rate and rise in blood pressure. Nicotine has adverse effects on your body, well-being, and also interferes with several transmitters in the brain.[1]

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What Neurotransmitters Does Nicotine Affect?

One of the neurotransmitters that nicotine interferes with its functionality is acetylcholine. Nicotine affects the normal relationship between acetylcholine and the receptors it binds to. The acetylcholine receptor is located in many brain structures and organs. It transmits messages related to heart rate, respiration, alertness, memory, and muscle movement. Nicotine interferes with acetylcholine and its receptors because nicotine is shaped similarly to the neurotransmitter and thus can bind with the receptors that acetylcholine binds with. As a result of this phenomena, the brain perceives that there is too much acetylcholine, thus reacts by reducing the number of receptors and releases less acetylcholine into the synapse.[1]

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Nicotine also affects plasma levels of glutamate by reducing them and results in an increase of serotonin and epinephrine. Glutamate is an amino acid neurotransmitter that is responsible for creating and storing memories in the brain. Nicotine results in reduced levels of this neurotransmitter in smokers, but then again, in the hippocampus and cingulate cortex region of the brain, there is no change in glutamate concentration for smokers. Serotonin is the neurotransmitter associated with feeling good and it makes one feel happy, relaxed, calm and even motivated.

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As much as nicotine results in increased levels of serotonin, a continued release of the neurotransmitter results in a decline over time, which impairs the functionality of serotonin in the long run. As a result of decreases serotonin levels, an individual experiences stress, anxiety, poor memory, fatigues, insomnia heart diseases, smoking addiction, and insulin resistance among other complications. Epinephrine is a catecholamine neurotransmitter that is associated with the fight or flight response of the sympathetic nervous system. This neurotransmitter exerts its tissue-specific effect by binding with particular receptors expressed in the target tissue. Nicotine results in an increased level of epinephrine.[2]

How Does Nicotine Affect Dopamine?

Nicotine also has an effect on dopamine, which is also a neurotransmitter. Dopamine is associated with feelings of euphoria and pleasure and is responsible for activating the dopamine reward pathway. The dopamine reward therapy works in that behavior naturally instigates the reward therapy through the feeling of pleasure and reinforces the behavior so that it over and over again.[3] Once nicotine is in your body, it activates receptors in the brain, which in turn causes the release of various neurotransmittersincluding dopamine. The dopamine released makes the smoker feel good and have a feeling of pleasure.

The more you smoke, the higher the number of nicotine receptors increases. Even when you try to stop smoking, since the receptors in your brain do not receive nicotine, the pleasure response is cut off thus resulting in nicotine withdrawal symptoms. So as to overcome these symptoms, you smoke a cigarette, which offers temporary relief by releasing dopamine thus activating the pleasure response.[4] Dopamine is a precursor of epinephrine and it plays a big part in the nicotine addiction process. Smoking results in an increased level of dopamine, which in turn stimulates the reward centers in the brain. This process attributes to the smoking behavior so that each cigarette makes a smoker desire yet another cigarette, and another.[2]

Conclusion

Nicotine has various effects on the brain, the central nervous system, and also implicated the cardiovascular system and even metabolism. In the brain, nicotine triggers the release of several neurotransmitters including dopamine, serotonin, epinephrine, glutamate, and acetylcholine. These neurotransmitters have various functions in the body, and with nicotine present in the body, it interferes with how these neurotransmitters bind with their respective receptors hence interfering with their roles in the body.

References:  

Sheetal DeCaria MD

Written, Edited or Reviewed By:

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Last Modified On: August 17, 2019

This article does not provide medical advice. See disclaimer

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