What Happens In The Pineal Gland When We Use Cannabis?
What is the pineal gland for?
While undoubtedly important, the pineal
gland does not possess mystical or supernatural properties, no matter
how much some people would like to believe it. Even some great, renowned
thinkers have fallen foul of magical thinking here, such as the
scientist and philosopher Descartes, who described the pineal gland as
“the seat of the soul”.
Indeed, it is just but one gland among
many that comprise the endocrine system in vertebrate animal species,
whose function is heavily involved in the regulation of circadian
(daily) rhythm and the production of hormones – the most important of
which being melatonin, the “sleep hormone”. However, there are a few
things that mark out the pineal gland as unique and interesting. Let’s
take a brief look at what they are.
Why is the pineal gland so unusual?
The pineal gland is thought of as the “third eye”, and does in fact possess some of the qualities of a simple organ of sight
The idea of the pineal gland being a
primordial “third eye” has some basis in fact. The gland is made up of
cells known as pinealocytes, which in some non-mammal vertebrate species
actually directly respond to light. This ability makes them very
similar to the cells of the retina, the part of the eye that receives
light from the lens opening.
In some fossil species, scientists have
even found holes just like eye sockets in the centre-rear part of the
skull, which allowed the pineal gland to receive light directly, just
like an eye. In fact, several modern species of reptile and fish still
retain a functional “third eye”, such as the New Zealand reptile species
the tuatara, whose extra eye actually has a lens, a retina and a cornea
of its own! It is thought that these functional third eyes are involved
in maintaining daily and seasonal cycles of hormone production.
In mammals, the pinealocytes aren’t known
to directly receive light, and there is no evidence of functional “third
eyes” existing. However, the pinealocytes of mammals are known to be
directly linked to the retina itself, which sends signals in response to
changes in light levels in order to regulate circadian rhythms. So in
some respects, if one stretches the definition of what constitutes an
eye to the limit, one could still say that the pineal gland functions
somewhat like a rudimentary third eye even in mammals.
One interesting aspect of the pineal gland
that certainly does apply to mammals, including humans, in this: unlike
much of the brain, the pineal gland is not separated from the rest of
the body by the blood-brain barrier. It receives abundant blood flow
directly from the posterior cerebral artery, which may have something to
do with its receptiveness to psychoactive substances.
Why do psychoactive substances often affect the pineal gland?
The New Zealand reptile the tuatara retains a functional third eye used for regulating daily cycles (Out Shooting photos)
As well as being in a perfect position to
receive all kinds of substances not filtered by the blood-brain barrier,
the pineal gland is also at the heart of a “cascade” of reactions which
fire off when norepinephrine, a well-known neurotransmitter responsible
for regulating sleep and wakefulness, binds to its receptors in the
pineal gland.
When norepinephrine binds to the receptors
(known as adrenergic receptors), the chain of hormonal and enzymatic
interactions that results is responsible for signalling when it is time
to sleep, and when it is time for the individual to wake and become
active. Thus, this cascade is deeply involved in setting up one’s
“mood”, and how one perceives and responds to the challenges of the
coming day, as well as ensuring that sleep of sufficient quality and
duration is regularly achieved.
Clearly, the pineal gland is essential to
maintaining a healthy, positive mind state, and is deeply concerned with
emotional states in general. When humans consume psychiatric drugs, it
affects this complex cascade of activity in the pineal gland, in
conjunction with various other parts of the brain, to give a
subjectively altered state of perception.
One example of the importance of the
pineal gland in terms of psychiatric good-health is its relationship
with the “Winter Blues” illness, seasonally affective disorder (often
abbreviated to SAD). The fact that bright light is a common treatment
for SAD suggests that the pineal gland and its associated light-sensitive hormone, melatonin,
is involved. Furthermore, the fact that low light levels can cause such
a dramatic set of psychological symptoms indicate that the pineal gland
is fundamentally linked with psychiatric good health in general, and
that its dysfunction may be behind other mental disorders too.
How does cannabis itself work in the pineal gland?
The pineal gland is so called due to its resemblance to a pine cone (Southernpixel – Alby Headrick)
Research on rats has shown that the pineal gland contains a functional endocannabinoid system,
in that cannabinoid receptors type 1 and 2, and the endogenous ligands
that bind to them, anandamide and 2-AG, are all present.
The study showed that the activity of the
CB?-receptors varied according to a daily cycle, with lowest activity
levels occurring at the end of the daylight period. It also showed that
levels of an enzyme responsible for synthesizing new endocannabinoid
molecules, NAPE-PLD, was reduced during the middle of the dark period.
Furthermore, the study showed that
presence of THC reduced the activity of an enzyme known as AANAT, and in
doing so reduces the synthesis of melatonin itself. An earlier study on rats also
showed that THC reduced the activity of AANAT, and suggested that the
mechanism that occurred was as follows: the neurotransmitter
norepinephrine starts a cascade of reactions, the end result of which is
the production of melatonin. THC disrupts this norepinephrine cascade
and thereby reduces the production of melatonin.
It is likely that THC’s endogenous
analogue anandamide performs the same action of reducing the
norepinephrine-induced release of melatonin, and is therefore
fundamentally involved in pineal gland function. It seems that low
levels of anandamide or THC are therefore needed in order for melatonin
production to increase. As melatonin levels increase, as they should
normally do at the end of the daylight period, feelings of sleepiness
should occur.
But smoking cannabis makes me sleepy! Why?
The pineal gland has long been seen as the seat of consciousness in humans (Dean Terry)
If low levels of anandamide are required
for melatonin production to increase, and levels of cannabinoid receptor
activity are lowest at the end of the daylight period, that seems to
imply that using cannabis would cause melatonin to be reduced, which
should mean that sleepiness is also reduced. But many people report
feeling sleepy after using cannabis. Why is this?
It may simply be that the mechanisms
relating to cannabinoids and pineal gland hormones work differently in
rats than in humans. Indeed, while the studies on rats clearly showed
that THC reduced melatonin levels, there is evidence to suggest that the
reverse is true in humans. An 1986 study showed that in eight out of nine healthy male volunteers,
THC caused melatonin levels to dramatically increase, peaking around
120 minutes after administration. Interestingly, however, one subject
showed a decline in melatonin in response to THC, just as was seen in
rats.
Whether or not cannabis makes one feel
sleepy may depend on dose, tolerance and a whole range of other factors,
and may even depend on the time of day that the user consumes cannabis
in relation to typical circadian rhythms. Furthermore, there may also be
a genetic element controlling individual response to cannabinoids, as
genetic differences in expression of cannabinoid receptors have been
noted in multiple studies.
It is also now thought that many of the
subjective effects of cannabis are not derived from THC per se, but
rather from THC in combination with various other cannabinoids and
terpenes. For example, myrcene is now thought to affect the “high” of
pure THC, giving an overall more “couch-lock” effect to the user.
Furthermore, pure THC has been shown on a number of occasions to have
either a sedative or stimulant effect, depending on dose.
But how does the pineal gland actually affect the process of getting “high”?
The pineal gland is heavily involved with the regulation of sleep and circadian rhythms in humans (Fl??d)
This is is not entirely clear, and in any
case, we know that multiple different regions of the brain are involved
in the subjective experience of being high. The pineal gland is just one
tiny link in an extremely long and complicated chain, which stretches
between some of the most basic and fundamental parts of the brain (and
the pineal gland can definitely be classed as basic and fundamental, as
almost every living vertebrate possesses one) and some of the most
advanced, such as the neocortex, which only exists in mammals.
However, the pineal gland has repeatedly
been associated with the biosynthesis of important natural compounds
related to sleeping, dreaming, and dream imagery. The presence of these
compounds in the pineal gland is one of the most important reasons that
so many view it as the “seat of the soul”, or a key to “spiritual
enlightenment”. Without a doubt, the most famous of these compounds is
N,N-Dimethyltryptamine, more commonly known as DMT.
It’s actually somewhat controversial as to
whether or not the pineal gland is responsible for synthesizing DMT in
humans, but there is significant evidence to suggest that it is the
case. DMT and related compounds tryptamine and bufotenin have been found in human urine, and DMT itself has been shown to be synthesized in the pineal gland of the rat brain. A closely related compound, 5-MeO-DMT has been found to be synthesized in the human pineal gland, but thus far, it has not been proven that DMT itself is too.
In any case, it certainly appears that the
pineal gland is very much involved in the production and/or processing
of substances that are well-known to be involved in helping to create
“dream states” when we are asleep. Thus, there are many theories that
the subjective experience of getting “high” from cannabis, hallucinogens
and other psychoactive drugs also involves this subjective creation of a
“dream-like” or otherwise altered reality.
Read also: 4 Things You Must Know About Your ‘Third Eye’ – One Of The BIGGEST Secret Kept From Humanity
The pineal gland is part of a complex and fascinating system
DMT is an ingredient in ayahuasca, a powerful hallucinogen whose users often produce art like this (Howard G Charing)
While we are far from having a complete
understanding of the complex network of chemical compounds that interact
in the brain, we are beginning to build a simple map of how all these
interrelated processes fit together. It is increasingly clear that the
endocannabinoid system is a fundamentally important messaging system
that helps to link together various parts of the brain, many of which
work together to give us the subjective experience of being “high”.
The pineal gland itself is crucial to this
process, and has undeniable importance as a source of
consciousness-altering compounds. It works with the endocannabinoid
system and various other regulatory systems to control our subjective
daily experience of mood, wakefulness and sleepiness, and when we
introduce external psychoactive compounds, this process can be altered
in fundamental ways, some of which can be greatly enjoyable to the
individual!
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