Serotonin
Serotonin is a monoamine neurotransmitter. Most of serotonin is produced in the intestinal tract.
It is primarily found in the enteric nervous system as well as nervous system. It is released during
agitation and vasoconstriction and becomes an agonist to other platelets. It regulates intestinal
movements. Serotonin uptakes increase after stimulation, which in turn stimulates myenteric
neurons and gastrointestinal motility. As a result, it could regulate mood, appetite, and sleep.
However, several antidepressants may interfere with reabsorption of serotonin after is
transmitted. Serotonin can be found in wide range of species. For example, in insect it could with
coping pain. It can also stimulate digestive e tract into expelling the seeds in plants.
Dopamine
Dopamine is a neuromodulator molecule. In our brains, dopamine functions as a neurotransmitter
released by neurons to send signals to other nerve cells. Though it is only synthesized in specific
regions but could affect multiple regions. One role of it is to control motivational component of
reward-motivated behaviors. The anticipation of rewards increases the dopamine and some
addictive drugs would increase dopamine release or block reuptake into neurons. Other pathways
include in motor control and other hormones. In popular culture, dopamine is considered as the
chemical of pleasure while some say that dopamine instead confers motivational salience.
Outside the nervous system, dopamine serves as a local paracrine messenger. Some diseases
relate to the dysfunctions of the dopamine system such as Parkinson’s disease and schizophrenia.
Social Norms
Norms are what most people in a group do and believe. Though people consider themselves as
individuals, but people have strong tendency to conform to others in the group. It has been
proven that peers serve as the most influential factors affecting one’s behaviors. People have
strong misperceptions about the peer norms. People tend to think that high risk and harmful
behaviors are typical among peers. Negative behaviors are generalized to the whole group when
majority hold healthy behaviors. The reason of this phenomenon is that people make their
conclusion based on partial information. They only notice information that gains the most
attention, which are generally bad behaviors that distorts the whole perception. This
misperception will have negative consequences. They may consider negative behaviors as norm
and tend to conform it. To deal with this problem, people should start to gather reliable
information to come up with the actual norms regarding behaviors.