Drugs and the Nervous System

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Drugs and the Nervous System

• 1. Why study drugs?
• combatdrug abuse
• combatanxiety, sleeplessness, depression,
  schizophrenia
• Good Drugs versus Bad Drugs?
• motivationappropriate or not? Abuse?
• help us understand mechanisms of the brain and
  how it works on a physiological level

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Sources of drugs

• Plant
• Tobacco (nicotine)
• Coffee (caffeine)
• Poppy (opiates)
• Coca (cocaine)
• Cannibis (marajuana)
• Fungus
• LSD
• Specialized Labs
• Produced in labs
• Methamphetamine (crystal ice)
• Ecstacy
• Many pharmaceutical drugs
• Many are designer drugs

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The chemistry of drugs
Effect neurotransmitters such as acetylcholine
learning and memory, muscle contractions norep
inephrine energy, () emotion, sympathetic
pathway serotonin biological rhythms, sleep,
emotion, mood, pain dopamine desire and
pleasure
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TERMS
Agonist mimics or increases the effect of the
neurotransmitter Antagonist blocks or takes
away from the effects of a neurotransmitter Affin
ity ability of a drug to bind to a
receptor Efficacy degree to which a drug
activates the receptor, once bound Mixed Agonist
/ Antagonist depends on dose or
amount effectiveness and side effects vary from
one person to anotherthe receptors are
controlled by genes of the individual.
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Pleasure chemical
Dopamine

• Neurotransmitter and hormone
• Released by hypothalamus
• Pleasure center for the brain
• Services sympathetic responses
• Excess dopamine can lead to psychosis
  (schizophrenia)
• Reinforces, motivates, and increases arousal and
  desire
• Food, sex, drugs, (addiction)

In midbrain (substantia nigra) controlled
muscle movements (Parkinsons) In frontal lobe
attention, creativity, problem solving. (ADD)
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Serotonin

• Neurotransmitter. Receptors found along the
  brainstem (pons)
• Regulates anger, aggression, mood, sleep,
  appetite, temp. regulation
• Imbalance can lead to emotional disorders such
  as
• depression, suicide, impulsive behaviors,
  aggression

• To treat depression
• block the re-uptake of serotonin
• more serotonin floating around in the
  synapsebetter mood!!

May lead to SIDS low levels in the
brainstembreathing, heart rate, blood pressure
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Norepinephrine

• Neurotransmitter and hormone
• Sympathetic pathway chemical
• arousal, excitement, increase heart rate, blood
  pressure
• Adrenaline (fight or flight)

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Acetylcholine

• Neurotransmitter.
• Acts in the somatic nervous system to help with
  muscle contraction
• it is broken down by an enzyme naturally in the
  body. People with Myasthenia Gravis have muscle
  weakness and fatigue. The enzyme can be blocked
  with medication, allowing acetylcholine to work
  longer, consequently increasing muscle strength.
• Acts in the autonomic nervous system to help
  with learning and memory.
• found in short amounts in Alzheimer's patients.
• agonists are used to help treat

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GABA
(gamma-amino butyric acid)

• Amino acid that functions as a neurotransmitter.
• Inhibits neural activityslows things down.
• With glutamate (metabolism), it is more widely
  present that all other chemicals combined.
  Found in 90 of all synapses!!
• Because its so widely present, its the reason
  why there are so many side effects to drugs.

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GLUTAMATE

• Amino acid that functions as a neurotransmitter.
• Major excitatory neurotransmitter in the
  braininvolved in brain plasticity, such as
  learning and memory
• Plays a central role in metabolism
• With GABA, it is more widely present that all
  other chemicals combined. Found in 90 of all
  synapses!!
• Because its so widely present, its the reason
  why there are so many side effects to drugs.
• Effects neural plasticitystrengthen the
  connection between neurons (memory)
• Neural plasticity leads to addiction.why?

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Electrical stimulation
Nucleus accumbens rich in dopamine
receptors. Amygdala emotion Hippocampus
memory VTA pleasure Locus Coeruleus addiction
motivation (increase adrenaline
secretion) Substantia nigra movement
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More specifically, drugs can Stop the chemical
reactions that create neurotransmitters. Empty
neurotransmitters from the vesicles where they're
normally stored and protected from breakdown by
enzymes. Block neurotransmitters from entering
or leaving vesicles. Bind to receptors in place
of neurotransmitters. Prevent neurotransmitters
from returning to their sending neuron (the
reuptake system). Interfere with second
messengers, the chemical and electrical changes
that take place in a receiving neuron
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Stimulants

• Increase the activity of the CNS.
• Mimic the stimulation of the Sympathetic NS
• Increase behavioral arousal
• Increase activity at dopamine receptors

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Crack
Cocaine

• Cocaine (Charlie, Snow, Coke) comes in the form
  of a white powder made from coca shrub that can
  be eaten, smoked, sniffed or injected
• Crack (Rock, Stone and Wash) is derived from
  cocaine hydrochloride, it too is white but in the
  form of crystals or rocks the size of raisins
  that are smoked.
• Increase the release of norepinephrineenergy,
  mood, and () emotion
• Bind to the transporters usually reserved for
  dopamine and norepinephrine. This causes
  increased levels of these neurotransmitters in
  the synapses.

Effects
feeling of invincibility, strength, and
confidence due to a powerful buzz. intense
talking and feelings of well being
high last about 10-15 minutes, disappearing
after 1 hourconsequently repeated doses are
needed to stay highconstant need for more
(expensive to maintain) Anxiety, restlessness,
weight loss, feelings of persecution, tiredness,
hunger, sickness, depression
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Dopamine re-uptake system
Dopamine is reabsorbed by membrane
transporters. This frees up the synapse for
more normal everyday functioning of the nervous
system, such as muscle movement and metabolism.
dopamine
Neuron
Membrane transporters
Dopamine is re-absorbed into the cell
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Mechanism of cocaine
cocaine
Neuron
Membrane Transporters
dopamine
Cocaine is blocking the re-uptake of dopamine.
Therefore, dopamine remains in the synapse and
over-stimulates.
dopamine
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Ecstasy
Common names E, Esky, Snowballs, Doves, New
Yorkers, Burgers, soap, love-drug.
Active chemical MDMA (methylenedioxy
methanptanine)
Ecstasy is a pill taken orally, but can be
snorted, and rarely injected Takes effect after
30 minutes and can last for several
hoursconsidered a hallucinogenic
stimulant Originally used as anger management
and marriage counseling medication!
Effects
Tingling body feeling and overall feeling of joy
and ecstasycan be accompanied by hallucinations
Urge to dance and overly affectionate with
people Aches, pains, dizziness, panic attacks,
depression, paranoia, insomnia, dehydration and
heat stroke. Respiratory problems and
seizures Linked to deaths in young people.also
,regular use can lead to depleted serotonin which
can lead to chronic depression (serotonin mood)
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Mechanism of Ecstasy
Serotonin is contained in vesicles in the
cell. Ecstasy mimics serotonin is easily
absorbed by the transporters. It then confuses
the cell and causes it to push serotonin OUT of
the cell. Serotonin is now in excess in the
synapse and over-stimulates the cell.
Serotonin
Neuron
Membrane transporters
Ecstasy
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Amphetamines
Common names Adderoll Bennies, Black
beauties, Dexies, Jollies, Speed, Uppers,
Ups, Wake ups.
The drug comes in the form of colored or
off-white powder and is packaged in a 'wrap' made
from an envelope of folded paper. It can be taken
by snorting or, swallowing, drunk e.g. with juice
or by injecting.
Effects
Person feels more confident, talkative and
cheerfulelevated mood Used to stay awake,
energy, focus, enhanced motivation (dance
stimulant) Need to eat or sleep is
diminished Causes excessive release of nor
epinephrine from storage sites in PNS, and causes
an increase in dopamine release. Mimic the
effects of norepinephrineincrease mood and
emotion

• Methamphetamine (Ice)
• Use as alternative to cocaine. Found as a
  crystalline salt and a has appearance of
  sheet-like crystal. Similar effect as cocaine,
  but last for hours. 90 of users become
  addicted!!
• Inhibits the re-uptake of dopamine and
  epinephrine, therefore increasing the time those
  chemicals spend in the system.

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Nicotine
Consumed in the form of cigarettes, cigars,
pipes, chewing, or sniffed in the form of snuff.
Approximately 30 of people aged 16 or over
regularly smoke. Most Tobacco is smoked in the
form of cigarettes
Cigarette smoke contains various substances such
as nicotine, tar, carbon monoxide and other
gases. Some of these substances are absorbed by
the lungs. Nicotine is the active addictive of
cigarette smoking as it builds up in the body.
The effects decline soon after stopping. As a
consequence the user may be left wanting more
after only a short time
Effects
Heart disease, Lung cancer, Heart attack,
Emphysema Highly addictive Withdrawal symptoms
include irritability, restlessness, depression
Increased risk of miscarriage or fetal defect if
pregnant mother smokes
Attaches to nicotinic receptors and increases
dopamine release in nucleus accumbens.
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Anabolic Steroids
Pharmaceutical examples Durabolin, Stanozol,
Dianabol
Derived from hormones which occur naturally in
the human body and are responsible for the
development and function of the reproductive
organs. Most synthetic anabolic steroids on the
market are derived from human testosterone,
however some are intended for use on animals and
should not be used on humans.
Effects
Users report that steroids help them recover more
easily from strenuous exercise. It has also
controversially been claimed that steroids
enhance athletic performance Aggression Shunted
growth in young people Increased blood
pressure Abnormalities in body development
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Caffeine
Found in coffee, tea, chocolate, sports drinks,
coke

• The action of caffeine is to block the
  neurotransmitter adenosine (caffeine acts as an
  antagonist)
• Antagonism of adenosine receptors by caffeine
  would appear to promote neurotransmitter release
  of epinephrine, thus explaining the stimulatory
  effects of caffeine

Effects
Constricts blood vessels in brain abstention
results in headache and restlessness due to
increased blood flow Long term effects or damage
are inconclusive
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Depressants

• Suppresses the activity of the central nervous
  system
• Activates the neurotransmitter GABA which is
  responsible for calming the CNS and promoting
  sleep
• dangerous because it slows breathing, heart rate
  and other vital functions.

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Heroin
Common names H, Smack, Junk, Gear, Brown,
Lady, white girl, horse, black tar, brown sugar,
goods, Harry
Opiate family Morphine, Oxycontin, Vicodan,
Percocet, Codeine Methadone, Demerol, Fentanyl

• Can be sniffed, smoked (chasing the dragon), or
  the powder can be dissolved in water and
  injected.
• Injection is most effective and quickest (few
  seconds) high, but also most dangerous overdose
  potential. Also, risk of disease (HIV/Hepatitis)
  and infection is high.
• Heroin depresses the brain activity including
  reflexes like coughing, breathing, and heart rate
  (overdose can lead to cessation of vital reflexes
  death.

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Effects of Heroin

• Stimulate the release of natural endorphins in
  the brain
• Heroin also blocks the release of Substance P
  from the brain stem and spinal cord. Substance P
  is responsible for transmitting pain signals.
• Inhibits the release of neurotransmitter GABA,
  which limits dopamine release. Since GABA can no
  longer regulate it, dopamine is released in huge
  quantities.
• It takes a long time for the body to replenish
  the dopamine, so the high is replaced by a
  tremendous low due to depleted dopamine levels.
• Over time, an addict can damage dopamine
  releasing cells, causing extreme lows and chronic
  depression.
• slowed and slurred speech, slow gait,
  constricted pupils, droopy eyelids, impaired
  night vision,
• warm flushing of the skin, a dry mouth, and
  heavy extremities sweating, Regular use tends to
  lead to poor health due to bad diet and chaotic
  lifestyle. Women user's menstrual cycle may be
  disrupted
• drug craving, restlessness, muscle and bone
  pain, insomnia, diarrhea and vomiting, cold
  flashes with goose bumps ("cold turkey"), kicking
  movements, jitters, cramps, constipation,
  collapsed blood vessels.
• Brain disintegration in chronic users

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Dopamine Inhibitors
Dopamine inhibitors attach to receptors and block
dopamine release. This allows the cell to
function normally.
Dopmaine
Neuron
Dopamine inhibitors (GABA)
Neuron
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Mechanism of Heroin
Heroin blocks the inhibitors
Dopmaine
Inhibitors cannot get out and inhibit dopamine
release
Neuron
Dopamine is now free to flow into the synapse.
Dopamine inhibitors
Heroin
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nimations.html
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Barbiturate

• Barbiturates (Barbs, Downers, Quaaludes) calm
  people down and in higher doses act as sleeping
  pills.
• binds to receptors in medullainterfere with
  breathing. Heart-rate. Overdose death.
• They come in a wide variety of different colored
  tablets and capsules of various shapes and sizes,
  bearing various trade names and markings. They
  are usually taken orally, but may be injected.
  Only prescribed for treating severe insomnia.
• A small dose makes the user feel relaxed and a
  larger dose puts the user to sleep. The effects
  are exaggerated by taking alcohol and results in
  intoxication

Categories Anti-anxiety. Anti-depressant,
Tranquilizers, (reduces emotional tension) Xanax,
Ativan, Valium, Prozac, Paxil, Zoloft Inhibit
the re-uptake of serotonin (sleep, mood, emotion)
so the chemical is more readily available at the
synapse
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Alcohol

• Alcoholic drinks consist of ethyl or ethanol
  alcohol and water. Alcohol is produced by the
  fermentation of grains or vegetables. Beer
  contains about 1 part alcohol to 20 parts water,
  wine is 2-4 times as strong as beer and spirits
  are even stronger.
• Beer and wine drinking almost certainly predate
  recorded history and are an integral part of
  everyday life
• Alcohol is absorbed into the bloodstream and
  starts to take effect within five to ten minutes.
• Effects GABA (inhibitory) and GLUTAMATE
  (excitatory) neurotransmitters.
• Activates the dopamine driven pleasure pathway.
  
• De-activates connections to the frontal
  lobecauses disinhibition.
• alcohol affects the pituitary gland that controls
  the flow of water released by the body as
  urineresults in dehydration and leads to a
  hangover
• Alcohol is packed with calories one gin and tonic
  contains the same amount as a bowl of ice cream
  so consistent use can lead to noticeable weight
  gain.
• gastric and liver damage
• 116 billion industry in the USA (3 billion in
  marketing alone!!)
• Average consumption is 20 gallons per year

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GABA is the bodys primary inhibitory
neurotransmitter
It prevents a neuron from firing by clogging up
the transporters.
GABA
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ALCOHOL helps GABA with its inhibitory effects
Therefore further preventing a neuron from
firing. Thats why it is a depressant.
Neuron
Alcohol
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GLUTAMATE is the bodys primary excitatory
neurotransmitter.
It causes a neuron to fire.
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ALCOHOL prevents glutamate from exciting the
cell, and consequently has sedative effects.
It causes a neuron NOT to fireand another reason
why alcohol is a depressant!
Alcohol
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Hallucinogens

• Distort perception
• Crossing overhearing colors and seeing
  sounds.
• Alters conscious, and causes psychosis (lose
  contact with reality)
• One of the oldest drugs used by man.

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Cannabis
Common Names marijuana, dope, grass, blow, puff,
hash, ganja, Buddha, wacky tobacky, chronic, Mary
Jane, skunk
Active ingredient THC tetrahydrocannabinol
Cannabinoid receptors in brain areas that
influence pleasure, memory, thought,
concentration, sensory and time perception, and
coordinated movement THC attaches to cannabinoids
receptors in the hippocampus and consequently
disrupts memory, motivation, mood, and learning.
It also interferes with the limbic systemcauses
emotional changes ranging from uncontrollable
laughter to paranoia.
Considered a hallucinogenic stimulant and also
has sedative effects. Users may feel more
talkative, more relaxed, experience a sense of
well being and being stoned (heightened
perception) often mentally distancing them from
their surroundings. Mild hallucinations and
strong feelings of affection may occur. Skunk is
a new strain of Cannabis that is extremely potent
causing very strong hallucinogenic
experiences paranoia, panic attacks, mood swings,
sleeping problems, short term memory loss and
reduced concentration No receptors in the
brainstem no effect on heartbeat Gateway drug
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LSD
Chemical name Lysergic Acid Diethylamide Common
name Acid, Trips, Tabs, Blotter, Doses
Most common psychedelic drug. Derived from a
fungus infecting rye
Often LSD is added to absorbent paper, such as
blotter paper, and divided into small, decorated
squares, with each square representing one dose
Used during the Cold War as truth serum during
CIA interrogations Beatles song Lucy in the Sky
with Diamonds Mimics serotonin because LSD
resembles serotonin in chemical structure users
experience severe, terrifying thoughts and
feelings, fear of losing control, fear of
insanity and death, and despair while using LSD.
Some fatal accidents have occurred during states
of LSD intoxication. Sensations may seem to
"cross over," giving the user the feeling of
hearing colors and seeing sounds. These changes
can be frightening and can cause panic. Highs
can last as long as 12 hoursaddiction to LSD
does not occur. User may have flashbacks and
bad trips where depression, schizophrenia, and
psychosis have been recorded
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Mushrooms
Common names shrooms, magic mushrooms,
mushies Chemical name Psilocybe Semilanceata
(Psilocybin)
Look like dried mushrooms and are usually eaten.
Can be brewed and consumed as tea and sometimes
cooked. Agonists to neurotransmitters GABA and
glutamic acid and effect hippocampus, cerebral
cortex, and cerebellum
Effects
Nausea is a common effect. Causes distorted
perceptions of touch, sight, sound and taste.
Other effects can include nervousness and
paranoia. Effects can be different during each
use due to varying potency, the amount ingested,
and the user's expectations, mood, surroundings,
and frame of mind. On some trips, users
experience sensations that are enjoyable. Others
can include terrifying thoughts, and anxiety,
fears of insanity, death, or losing control.
Poisoning can result in vomiting, diarrhea,
stomach cramps, loss of consciousness and
convulsions and death
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PCP
Chemical name Phencyclidine Common Name
angel dust, ozone, wack, rocket fuel
Act by altering distribution of the
neurotransmitter glutamate throughout the brain.
Glutamate is involved in a person's perception of
pain, responses to the environment, and
memory. Effects PCP is a "dissociative drug,"
meaning that it distorts perceptions of sight and
sound and produces feelings of detachment
(dissociation) from the environment and self
Intoxicated individuals may act in an
unpredictable fashion, driven by their delusions
or hallucinations. Included in the portfolio of
behavioral disturbances are acts of self-injury
including suicide, and attacks on others or
destruction of property
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Summary
Stimulants
Depressants
Hallucinogens
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Endocrine System
1. _____________________ ________________________
____ 2. ____________________ ____________________
________ ______________________ 3.
____________________ ___________________________
_ 4. ____________________ ______________________
______ 5. ____________________
____________________________ 6.
____________________ ___________________________
_ 7. ____________________ ______________________
______ ______________________ 8.
____________________ ______________________
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1. Pineal Body Melatonin patterns of wake and
sleep 2. Pituitary Master gland. Stimulates
other glands Oxytocin uterine contractions
during labor, birth, breastfeeding Prolactin
stimulates milk production after birth in
females Vasopressin water retention, constrict
blood vessels 3. Thyroid Controlled by
pituitary and hypothalamus. Determines how
quickly energy is burned by body Thyroxin
controls rate of metabolism 4. Thymus Immune
system stimulant 5. Adrenal Sympathetic
response Adrenaline (epinephrine)stimulates
fight or flight 6. Pancreas aids in digestion of
food Pancreatic juice contains many digestive
enzymes 7. Ovaries female reprodcutive
organ Estrogen sex characteristics, regulates
menstration Progesterone maintains uterus
during pregnancy 8. Testes Male reproductive
organ testosterone male sex characteristics
produce sperm
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5 signs of dependence 1. Time thinking about
it 2. Doing more each time 3. Desire to
stop 4. Withdrawal symptoms 5. Tolerance