Glossary of Terms



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.

Anorexia
    Loss of appetite.

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.

Lethargy
    Abnormal drowsiness.

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.


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