64 | SCIENCE ILLUSTRATEDSeveral countries
allow cannabis
While scientists are discovering the exact
functions of cannabis, nations are amending their
legislation, allowing the active ingredients of the
controversial plant to cure more people.CANNABIS
CONSUMPTION
IS LEGAL
A number of countries allow
cannabis for recreational use or
as medication. In most of them,
sale and growing requires
special permits.CANNABIS IS LEGAL
FOR MEDICAL
PURPOSES
Several countries are making it
legal to use medical cannabis,
as the effect has become better
understood thanks to years of
diligent research.PRIVATE USE OF
CANNABIS IS
TOLERATED
Although the legislation still
bans the use of cannabis, a
number of nations’ police and
courts tolerate its use in
many cases.However, the studies
did involve some problems.
Even in small doses, cannabis
causes side effects, and no
less than 79 % of the epilepsy
patients felt tired, groggy, or had diarrhoea.
30 % suffered so much that the scientists
talked about severe side effects.
Consequently, scientists have long
dreamt of mapping out the ingredients of the
cannabis plant so accurately that they can
use their medical potential without causing
any side effects.PLANT INGREDIENTS
WORK DIFFERENTLY
Scientists are particularly interested in two
cannabis plant ingredients: THC and
cannabidiol. THC causes people to be "high",
whereas cannabidiol reduces the effect. The
implications of THC are well-known, whereas
the effect of cannabidiol remains uncertain- scientists only know that the ingredient
adjusts the signals of brain cells, affecting
all of the brain. So, doctors also differ
between the two ingredients, when they use
them for medical purposes. Studies show
that cannabidiol is more efficient against
multiple sclerosis and post-traumatic stress
disorder, whereas THC eases the nausea of
cancer patients undergoing chemotherapy.
Patients, who need pain relief, seem to get
the best results, if they consume the entire
cannabis plant, getting both ingredients at
the same time.ALTERED BRAIN SIGNALS
For the past 14 years, Dutch pharmacies have
sold the Savitex mouth spray, which includes
both THC and cannabidiol, whereas the
synthetic version of THC is sold as pills by the
name of Nabilone.
When the THC of the drugs is absorbed by
the body, the ingredient binds to cannabis
receptors. Scientists know of two such
receptors: CB1 and CB2. The first type is
primarily located on the surface of brain
neurons, whereas the second one is more
common in the body.
The receptors function as a type of
antennas, which detect THC in blood, lymph,
etc. When THC binds to a cannabis receptor,
a signal is triggered off in the cell, which
could have highly different consequences.
In the brain, CB1 receptors control the
signalling of brain cells, and when they areactivated by THC, they either send more or
less signals than they usually do. The
patient's perception of time and place is
changed, his attention becomes sharper,
sensory impressions improve, and he feels
relaxed – in other words all the well-known
effects of cannabis.
Normally, CB1 receptors are activated by
two natural ingredients, anandamide and
2-AG. Their binding could theoretically make
a brain cell in the frontal lobe more sensitive
to the serotonin neurotransmitter and less
sensitive to dopamine, causing the cell to
send more signals to the centre of fear,
amygdala, and fewer to the centre of
memory, hippocampus.
The brain is constantly regulating its
own function by adjusting the quantity of
CB1 receptors or the two ingredients which
bind to them. And the flow of nerve signals
in the brain’s fine-meshed neural network is
key to the way in which our brain learns,
remembers, and processes the body’s sen-
sory impressions.
Inside the body, THC binds to the CB2
receptors, which are located on the
specialised white blood cells of the immune
system. There, the CB2 receptors control theSHUTTERSTOCK & GÜRCIN ALTINKAYA
URUGUAY IS
THE ONLY
COUNTRY, IN
WHICH IT IS
ALLOWED TO
POSSESS, SELL,
AND GROW CANNABIS.