Action potential
The acute change of the electric potential from a negative
charge to a positive charge across a plasma membrane. This is the cellular representation of an external stimulus.
Acute Renal Failure
Acute renal failure occurs when the renal tubes (kidney
pathways) are blocked by protein pigment in the muscles (myoglobin) as a
result of muscle damage. Dehydration increases the risk of acute renal failure
(Baggot et al. 2001).
Adrenocoritcotropic Hormone, Cortisol, and Prolactin
Adrenocorticotropic hormone stimulates the production
of steroid hormones, specifically cortisol. Cortisol increases the blood-sugar
level. Prolactin triggers and maintains milk production after birth.
Amino Acid
Organic compounds containing both an amino group(-NH2)
and a carboxyl group(-COOH). Amino acids are the building blocks from which
all proteins are constructed.
Amphetamine
Stimulant drugs that affects the release of the neurotransmitters
dopamine and norepinephrine, affecting alertness concentration.
Amygdala
An almond-shaped structure in the temporal lobe; part of the
limbic system. The amygdale is thought to play a prominent role in the
integration of brain systems that are responsible for emotional behavior.
Antidiuretic Hormone
(Vasopressin)
This hormone stimulates the reabsorption of water by
the kidneys and can increase blood pressure.
Antioxidant
A substance which inhibits oxidation or a reaction which
is fueled by oxygen or peroxide. The breakdown of dopamine by MAO is inhibited
by antioxidants.
Axon
The segment of a nerve cell which sends information to
another cell. In the axon, information is represented by electrical and
chemical changes in both its internal environment and its immediate surroundings.
Carboxyl group
A group of atoms that includes a carbon atom double-bonded
to an oxygen atom and single-bonded to a hydroxyl group (-OH). Usually denoted
thus: -COOH.
Caudate Nucleus
A nucleus that supplies input to the basal ganglia, which
scientists believe control movement. The caudate nucleus is thought to control
voluntary movement.
Cocaine
A bitter, addictive anesthetic (pain blocker) which activates
neurons in the dopaminergic system causing intense feelings of pleasure.
Cocaine's interaction with the dopaminergic system is also the cause of
its addicitive properties.
Dendrite
The part of a nerve cell which will recieve information
from the terminal buttons of an axon relay it towards the body of the cell.
Once the information reaches the body it can then be sent through the axon
and ultimately to another cell.
Dopamine
The neurotransmitter which is produced by the nucleus
accumbens and acts as a pleasure producing substance when released into
the many regions of the brain which it affects. If an individual uses cocaine,
dopamine is released in high quantities and the user will experience intense
pleasure.
Ecstasy
The common street name for MDMA, also known as XTC, Rolls,
Pills, Beans and "X". Ecstasy often contains other substances
in addition to MDMA and sometimes contains no MDMA at all.
Enzyme
Any one of the complex proteins produced by living cells
which acts as a catalyst (increases the liklihood that a reaction will occur)for
specific biochemical reactions. MAO is an example of this. It causes the
breakdown of dopamine inside the terminal buttons of nerve cells.
Heart Fibrillations
Heart fibrillations are very rapid irregular contractions
of the heart resulting in desynchronization of the heartbeat and pulse.
Hallucinogen
The term "hallucinogen" is used interchangeably with
"psychedelic" to describe a category of mind-altering substance, despite the
fact that such drugs do not produce true hallucinations
(Perrine, 1996). Psychedelics include: LSD, mescalin and psilocybin.
Hippocampus
This structure, located in the temporal lobe, is thought to
be the area in the brain where information is processed and integrated into
memories. The hippocampus contains cells that change in a way that corresponds
to learning.
Homeostasis
Homeostasis describes the unending process by which the
body attempts to keep its internal environment at a state of equilibrium
while simultaneously being pushed away from equilibrium by the input recieved
from the external environment.
Hydroxyl Group
A group of atoms that consists of an oxygen atom single-bonded
to a hydrogen atom, usually denoted as: -OH.
Inhibit
Inhibition is the effect of a drug that will decrease
the liklihood that a certain biological event will occur. An example of
this is prozac. It will inhibit the reuptake of seratonin which means that
the serotonin in the synapse between two nerve cells will not be taken back
into the terminal button.
Ion
Ions are groups of atoms which carry either a positive
or a negative electric charge due to the loss or gain of an electron. Ions
are important in information transmission in nerve cells because their movement
in and out of the plasma membrane allows for the alteration in electric
potential and ultimately the production of an action potential.
Jaundice
Yellowish coloration of the skin, tissues, and body fluids.
LSD
LSD is a drug which has a similar molecular makeup to
seratonin. The effects of LSD are thought to be produced by a stimulation
of the serotonin receptors of the neurons located in the raphe nuclei.
LSD is classified as a hallucinogen and is a Schedule I federally restricted
drug, meaning that it is thought to have high potential for abuse, has no
currently accepted medical implementation and is not considered safe enough for
use under medical supervision.
MAO
MAO is an enzyme which acts in the body to assist in
the digestion of food and to inactivate neurotransmitters, like dopamine
and serotonin, when they are no longer needed.
MDMA
Methylenedioxymethamphetamine. This substance has effects in
the human body that are similar to those of both amphetamine and psychedelic
drugs. These effects are currently thought to be caused mainly by the way in
which MDMA interacts with brain systems that use the neurotransmitter serotonin.
MDMA is classified as a hallucinogen and is a Schedule I federally restricted
drug, meaning that it is thought to have high potential for abuse, has no
currently accepted medical implementation and is not considered safe enough for
use under medical supervision.
Medulla
The medulla is the primary are in which many of the motor
tracts cross as they come up through the spinal cord. Being that it is a
very basic part of the brain, it controls many of our most basic functions
such as reflexes, gagging, coughing, vomiting, and swallowing.
Midbrain
Located in the same area as the midbrain (the brainstem)
the midbrain is also considered one of the basic and primal brain structures.
It is in change are visual and auditory reflexes and serves as the nerve
pathway between the two hemishperes.
Monoamine
A class of neurotransmitter that includes serotonin, dopamine and norepinephrine.
Neurotransmission
Neurotransmission is the passage of information (electrical
impulses) across a synapse. This process involves the neurotransmitters
being released into the synapse from the vesicle due to a change in the
electric potential of an axon. Some of the neurotransmitters will traverse
the synapse and bind with the dendrite of another nerve cell located on
the other side. If enough neurotransmitters bind to the dendrite, the dendrite
will experience a change in its electrical potential resulting in the productino
of an action potential. This will allow the continuation of the information
to other nerve cells.
Neurotransmitter
A substance such as dopamine or seratonin which will
carry information (electrical impulses) across a synapse when stimulated
by an electrical impulse.
neurotransmitter binding
Neurotransmitter binding occurs when the neurotransmitters,
released from the vesicles, connect with the receptors of the dendrite and
cause an action potential to occur.
Neuron
A neuron is a nerve cell which normally consists of an
axon, a dendrite and a cell body. These cells allow the body to experience
the external environment by translating the information in the external
world into something which can be processed internally, namely electric
impulses.
Nucleus Accumbens
The nucleus accumbens receives input from dopamine-secreting
neurons that originate in the ventral tegmental area. This nucleus is thought
to be the primary target of neurons involved in the brain's natural reinforcement
circuit.
Nystagmus
Lateral eye wiggle which can be caused by MDMA use
Parkinson's Disease
This degenerative disorder involves a loss of
dopamine-secreting neurons in the substantia nigra, whose output to the basal
ganglia controls movement. Parkinson's disease manifests itself in tremors,
rigid movements, trouble initiating movements and poor balance.
PET scan
A PET scan is a method of measuring the level of activity
in a certain brain region during a mental task. If we wanted to measure
what happens when someone speaks we would first 1) inject a small amount
of harmless radioactive matierial with sugar into the brain which will emit
particles that can be measured by a PET scanner, 2) have the patient speak
about what is on their mind while their head is in the PET machine 3) examine
the printout which will show that the regions with the most activity used
the most sugar and since the sugar was connected to the radioactive material
we can deduce that the most particles were emitted from the areas that were
most active.
Pons
The structure in the brain which connects the medulla
with the higher cortical areas of the brain. The higher cortical areas are
the ares of the brain which form associations and are thought to coordinate
the importance and order in which information will be processed and acted
upon. Thus, if a person fighting four grown men in a bar brawl were to gag
on their saliva (a process casused by the medulla) it would have less of
an effect due to the decision of the higher cortical areas to dedicate all
energies to the task at hand.
Psychedelic
The term "psychedelic" was originally used to refer to the
"mind-opening" quality of the drugs that belong to this category. The term
"hallucinogen" is used interchangeably with "psychedelic", despite the fact that
such drugs do not produce true hallucinations
(Perrine, 1996). Psychedelics include: LSD, mescalin and psilocybin.
Putamen
A region that supplies input to the basal ganglia, which
scientists believe control movement. The putamen is thought to control voluntary
movement.
Reuptake
The process by which terminal buttons of axons will take
certain neurotransmitters out of the synapse in order to clean up or to
reduce their concentration. Reuptake is inhibited with drugs such as Prozac
which is a well known SSRI (selective serotonin reuptake inhibitor).
Serotonin
Serotonin is a neurotransmitter that is implicated in
the control of many functions of the body including sexuality, hunger, sleep
cycles, and mood. It the primary neurotransmitter which MDMA affects.
Serotonin axon
Serotonin axons are certain axons that emit the neurotransmitter
serotonin when they are stimulated by an electrical impulse.
SSRI
SSRIs are defined as selective serotonin reuptake inhibitors.
They inhibit reuptake centers by plugging them up and not allowing anything
to enter. The inhibition of the reuptake centers will result in an increase
in the synaptic concentration of serotonin and other neurotransmitters which
may need to be cleaned up (excess dopamamine resulting from injestion of
MDMA).
Substantia Nigra
This area is named for its darkly-colored cells, which are
stained black with the byproduct from dopamine metabolism. Output from the
substantia nigra goes to the caudate nucleus and putamen of the basal ganglia,
which are involved in movement.
Synapse
A synapse is the microscopically small area that lies
between the terminal button of an axon of one cell and the dentrite of another
cell. This space is where the neurotransmitters are released.
terminal buttons
The terminal buttons of an axon are the regions in which
the vesicles are housed. There are thousands of them on some axons, giving
the axon the ability to connect with many dendrites. It is the endpoint
of the axon which will release neurotransmitters into a synapse after the
reception of an electrical impulse.
Trismus
Jaw clenching and tooth grinding, a common side effect of MDMA use.
Tryptophan
Tryptophan is an essential protein, and must be obtained
through the diet. Tryptophan is found in foods such as milk, cheese, meat, ham,
peanuts and cottage cheese.
Ventral Tegmental Area
The site of origination of dopamine-secreting neurons that
are part of the mesolimbic system, which originates in the VTA and terminates
in the amygdale, hippocampus and nucleus accumbens.
Vesicle
A small fluid filled sac which is located inside of the
terminal buttons of an axon. Vesicles will collect neurotransmitters in
the termianl button and release them when they recieve an electric signal
which directs them to do so.