University Assignment: Mesotelencephalic Dopamine System in Addiction

This essay critically discusses the role of the mesotelencephalic dopamine system in addiction. It explains the system's components, including the nigrostriatial, mesolimbic, and mesocortical pathways, and their functions in regulating incentive salience, motivation, and cognitive processes. The essay emphasizes the mesolimbic pathway's involvement in the rewarding effects of drugs, highlighting the role of dopamine in reinforcing pleasurable experiences and contributing to addiction. It details the pathway from the VTA to the nucleus accumbens and amygdala, explaining their roles in desire and emotional responses. Furthermore, the essay references different dopamine pathways, including mesolimbic, mesocortical, nigrostriatal, and tuberoinfundibular pathways. It explains how the mesolimbic pathway is associated with addiction, describing how addictive substances trigger dopamine release, leading to reward experiences, and how this system influences behavior. The essay also mentions the use of dopamine-related strategies to reduce addiction, referencing studies on dopamine receptor blockage and its effects. Finally, the essay references several studies and sources to support its arguments.

Brain and behaviour

Q2. Critically discuss the possible role of the Mesotelencephalic Dopamine System in addiction.
Answer – This is the essential system of brain and that is consist of three major
components such as the nigrostriatia, mesolimbic and mesocortical pathway. This pathway in the
brain made of cell bodies in the area of ventral tengmental and substantia nigra which further
involve numbers of regions that is perfonatl cortex, nucleus accumbens, striatum and amygdala.
Function of this system is to regulate the fillings such as the incetive salience, motivation, fear
between the the other cognitive processes (Sarkar et al 2019). This pathway play important role
in the development of rewarding effects of drugs. So this is the system which manages the
rewarding effect of drugs, although experts are still evaluating and study that how it works, it
has been analysed that neurotransmitter of the pathway guide the brain to avoid unpleasant filling
and attract towards the pleasurable things. As it reinforcing the brain to search for pleasure and
in this way this dopamine is associated with addiction. Mesolimbic pathway is the way of
dopamine transport from the VTA to the nucleus accumbens and amygdala. As it the nucleus
accumbens is present in the ventral medial portion of the striatum so that's why it is known to
play important role in the development of desire and placebo effects. Amygdala is the essential
component of the limbic system which is known to responsible for the emotional fillings in
humans. There are four different dopamine pathways in the brain which are mesolimbic,
mesocortical, nigrostriatal and tuberoinfundibular pathway. It play role in the cognitive
sensations, so it has been found that according to some theory's mesolimbic pathway is
associated with the addiction and depression so in that way it pay role in the drug addiction. The
addiction pathway is explained as the system which influences the behaviour and which plays
vital role in the addiction of particular drug or substance (Grabo, Spisak and van Vugt, 2017). It
is been explained that pathway is hidden deep into the brain as it has little complex structure as it
starts in the ventral tegmental area in the brain which is at the top of the brainstem. There are
neurotransmitters whose work is to pass the message among the gaps and dopamine is one of the
common neurotransmitter which is been recognised till now and it is one of the major
neurotransmitter in the brain in terms of reward pathway. Addiction in the brain revolves around
the mesolimbic dopamine pathway which is also known as the reward path and it starts form the
ventral tegmental area situated above the brain stem. Dopamine cell bodies works near the VTA

and their axons leads to nucleus acumens. There are different dopamine fibers which works for
the memory, planning and behaviour in social situations (Ng, 2018). Reward is experienced
during the activation of mesolimbic pathway dopaminergic pathway and there are different
things which influences mesolimbic dopamine such as food, sex or alcohol, drugs etc. The
stimulus cocaine have send the mesolimbic dopaminergic signal directly to the DA receptor
which through the different synaptic mechanism. There is direct effect on the dopaminergic
activity as it is considered as one of the reward stimuli and it becomes the topic for the further
study of dopaminergic structure. Dopaminergic structure sends the signal regarding the drugs
such as cocaine and it considered as reward for the individual. Dopamine is the vital part in
engaging the individual with other habit of drugs and dopamine is used to change the habit and
reduce the addiction of the individual to the drugs (Sarkar, Kochhar and Khan, 2019). Dopamine
is the neuron transmitter which focuses on the addiction of the different things either natural or
kind of drugs. Addiction is the habit of the thing which is very usually used by the individual as
the dopamine works as the transmitter for that addiction. Generally this technique of the
dopamine is used to improve the situation of the drugs addicts as the dopamine plays the role of
transmitter and it acts as a reward stimuli when it comes to the drugs so specialist focus on
individual addiction and tries to change that drug addiction into some other thing such as reading
the books, going out, eating food etc. and the specialist tries to use these stimuli as the reward
dopamine transmitter which helps in reducing the addiction of drugs in the individual.
Dopamine is the potential tool for the doctors to reduce the addiction of drugs in the individual
as it is important that higher amount of dopamine shouldn't be released as it creates the danger of
damaging the mind of the individual. It is been shown in the several studies that addiction in
every individual revolves around the mesolimbic dopamine pathway and it works towards
providing the good experience to the individual which can please them and tries to avoid the bad
experience in the mind of individual and it also act as the tool for providing the pleasant
experience to the individual. Studies have done on the animals regarding the blockage of
dopamine receptors and studies shows that it effects the mind in negative way and this leads to
the theory which states that the drugs releases the dopamine but it is considered as the
psychoactive and other non-addictive drugs do not considered as psychoactive (Sorrells and et.
al., 2018). Dopamine system released when individual uses the drugs such as cocaine, nicotine,
alcohol etc. which is not good for the individual and damages the brain cell of the individual.

REFERENCES
Grabo, A., Spisak, B.R. and van Vugt, M., 2017. Charisma as signal: An evolutionary
perspective on charismatic leadership. The Leadership Quarterly. 28(4). pp.473-485.
Ng, B., 2018. The neuroscience of growth mindset and intrinsic motivation. Brain sciences. 8(2).
pP.20.
Sarkar, S., Kochhar, K.P. and Khan, N.A., 2019. Fat Addiction: Psychological and Physiological
Trajectory. Nutrients. 11(11). Pp.2785.
Sorrells, S.F., and et. al., 2018. Human hippocampal neurogenesis drops sharply in children to
undetectable levels in adults. Nature. 555(7696). pp.377-381.