As nicotine mimics this neurotransmitter, it can
bind to the same cholinergic receptors. This
results in unregulated stimulation and activation
and the body also produces more acetylcholine
as a response. The activation and stimulation of
cholinergic receptors leads to an increased release
of dopamine that would not naturally occur.
Dopamine is involved in several physiological
processes such as attention, learning and
emotional responses. The release of dopamine
also contributes pleasurable experiences including
satisfaction and is a part of the mesolimbic
pathway (also known as the reward pathway). The
dysregulation of this pathway is a known major
component in cases of addiction.
Nicotine also stimulates the release of several
other neurotransmitters such as glutamate,
hydroxybutyric acid (GABA) and endorphins which
can have pain relieving effects and lead to a feeling
of euphoria.
Smoker feels
instant relief /
pleasure
Nicotine
reaches brain
in 7-10 secs
Smoke a
cigarette
THE
CYCLE
Nicotine
levels drop
quickly
Smoker feels
discomfort
(withdrawal)
Effects of nicotine withdrawal
SYNAPSE WITHOUT NICOTINE
LESS
DOPAMINE
RECEPTOR
LESS
ABSORBED
DOPAMINE
People who use nicotine-containing products experience many things
that they fi nd pleasurable as a result of nicotine’s interaction within the
body and its chemical pathways. However, with consistent exposure to
nicotine, tolerance to its effects develop rapidly from neuroadaptation.
When this develops, NICOTINE
the number of binding sites on cholinergic
receptors and others increase from desensitisation. When tolerance
has developed, these receptors become more active in periods of
abstinence causing the sensation of withdrawal and craving.
Cessation of nicotine can cause several withdrawal symptoms,
such as irritability, anxiety, depressed mood and increased appetite,
leading to the basis of nicotine addiction. As soon as you stop taking
nicotine your body will soon start to crave it, with that longing for the
next cigarette or vape occurring in as little as 2 hours.
Symptoms of nicotine withdrawal usually occur after 4-24
hours and most often
peak on the third day before diminishing
MORE
over several weeks. Relapse is often the result of desire to alleviate
DOPAMINE
symptoms through the administration of further nicotine. It has been
demonstrated that cognitive defects occur during the process of
abstinence, such as decreased attention and working memory.
Another issue of nicotine withdrawal is the behavioural element, such
RECEPTOR
as routine and other social
aspects, such as lunch breaks or nights
out with friends that make quitting diffi cult.
Going through a cold-turkey approach is often diffi cult due to the
MORE
strength of withdrawal
symptoms. It has been shown through
DOPAMINE
research that nicotine
replacement therapies can increase the
likelihood of successful
cessation. One such approach is e-cigarettes,
ABSORBED
where the user can start off on an appropriate strength nicotine and
progressively over time, decrease the nicotine strength in a tapered
approach until replacement is no longer required.
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