nucleus accumbens the nucleus accumbens, part of the limbic system plays a role in sexual arousal...
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Nucleus accumbens The nucleus accumbens, part of the limbic
system plays a role in sexual arousal and the "high" derived from certain recreational drugs. These responses are heavily modulated by dopaminergic projections from the limbic system.
Lobotomy of Phineas Gage Ventromedial region
of both frontal lobes Personality change
◦ irreverent, profane Prefrontal cortex
functions ◦ planning, moral
judgement, and emotional control
Rats in Skinner boxes with metal electrodes implanted into their nucleus accumbens will repeatedly press a lever which activates this region, and will do so in preference over food and water, eventually dying from exhaustion. In rodent physiology, scientists reason that the medial forebrain bundle is the pleasure center of rats( and humans). If a rat is given the choice between stimulating the forebrain or eating, it will choose stimulation to the point of exhaustion.
There is a Pleasure Center!
Mainly to Become Aware of the Drug Addiction that may result from some drugs.
Why Study Drugs In Health Science?
Reinforcement- gives person pleasure Compulsion or craving- person feel need to
do it again Loss of control- Persons often denies he has
problem Escalation- person gives more time to
behavior Negative Consequences-interferes w/ life
Addictive Behavior
1. Drugs Can Be Addictive 2. Drugs Can Cause Negative Side Effects Some with Short-Term Use Most with Long-Term Use We Don’t Know All of the Long-Term
Consequences of Many of the Drugs. 3. Drugs can impair judgment; this causes
higher risk: for auto accidents; engagement in unsafe sex, violence; more likely to be involved in an accident involving drowning, falling aggression and sexual assault.
Why Teach About Drug Use?
Definition for DRUG
Chemicals, other than food, intended to affect the structure and function of the body
Anyone who has an addictive personality.◦ Habits that get out of control.◦ Negative impact on health.
Moral weakness v. brain biochemistry.◦ Actions increase tolerance. Yes, some people have
more genetic predispositions to addictions!
Who is susceptible?
How Long Have Drugs Been Around?
Purpose? Function?
Where Do Drugs Come From?
How Do We Define a Drug Anyway?
Just a Bit of Drug History…
Plants were used in early humans in either of 2 ways:
1. Religious Ceremonies ( People believed that be consuming the drug they could communicate with God)
2. A Plant or its extract was used Medicinally
The First Drugs Came from Plants
The part of the plant for pharmalogical effect is called the ACTIVE INGREDIENT
Examples: Morphine and Codeine are Active Ingredients of the plant Opium
They are NARCARTIC analgesics
Active Ingredient
Digitalis (Otherwise Known as Foxglove)The active ingredient here is Digitoxin, a
heart medicine.
TODAY…Still, most medicine comes from Plants…..Pretty Flowers Give Heart Medicine
Known to the Aztecs , who considered this hallucinogen a divine messenger.
In 1692, Indians established the mission El Santo de Jesus Peyotes
Slice and Dry Buttons/ 4-12 are ingested At ritual…Period of meditation followed
by periods of nausea and vomiting BUT they would see>>> VISIONS of Kaleidoscopes of jewels ( Lasts 6-10 hours)
Peyote: A Trip
Best and Banting discovered they could make dogs diabetic by surgically removing their pancreases
Then curing the dogs by injecting them with extracts from the pancreas ie. Insulin.
BEEF and PORK pancreas are sources for most of insulin sold today.
Animal Sources Too
Any drug that alters your state of mind.◦ Your perceptions.◦ Your experience.
Natural or man-made
What are psychoactive drugs?
Drug Abuse involves behavior addiction as well as chemical addiction.
Psychoactive Drug- a drug that alters one’s state of consciousness or can causes intoxication.
Addictive Behavior- are behaviors that have gotten out of control , with resulting negative effects on one’s health. All psychoactive drug are addictive because of the way they work in the brain.
Drug Abuse
Tolerance- A physical adaptation of a substance that causes it to become less effective with repeated use. YOU NEED MORE EACH TIME TO GET THE SAME EFFECT!
Dependence- Occurs when person is so physically attached to drug she/he can’t live comfortably with/out it. See APA criteria in text. This person has withdrawal when drug is taken away
Withdrawal- Physical symptoms such as nausea, tremors …pain…can be dangerous.
Drug Terms
Intravenous injection, also called Mainlining (Most Effective Way)
Subcutaneous- under the skin Dermal or subdermal absorption-
(topical) can be placed on a stamp or suppository. LSD .
Swallow ( pill) Smoke it Inhale it
Different Ways To Take Drugs
1. Pharmacological Properties : of the drug its overall effects on a person. This includes how it effects the person’s body chemistry, behavior and psychology.
How Drugs Affect The Body: Drug Factors: (5)
2) Dose-response Function- Relationship between dose taken and intensity of effect.
3) Time-Action Function- How much time has elapsed and the intensity of effect.
)
Cont. of Drug Factors
4) Drug Use History- Influences the effects of and response to a drug. ( Meaning that the user may have to refrain from using a drug for a while to get the same effect from a given dosage)
5) Method of Use- Affects the strength of response ( swallow pill , inhale smoke or IV
Cont. of Drug Factors
Neurotransmitter - A chemical messenger released from the synaptic terminal of a neuron at a chemical synapse that diffuses across the synaptic left and binds to and stimulates the post-synaptic membrane.
Examples of neurotransmitters are
epinephrine, dopamine, seratonin and acetylcholine.
When in the neuron, neurontransmitters are stored in vessicles.
NEUROTRANSMITTERS
Most drugs of abuse seem to activate “reward” circuit(s) in the brain◦ Dopamine is a (the) principle one◦ Reward circuit(s) important for normal
functioning & learning Food, sex, & other necessary activities that are
enjoyable (interacting with others, mastering a task, etc.)
All (most) behavior is channeled through these reward circuit(s) – do not have completely difference systems for sex, hunger, etc.
Recent research suggests that it is possible to separate systems – “liking” vs. “wanting”◦ “Liking” - system responsible for pleasure◦ “Wanting” – system that drives behavior
Drugs & Reward
Most drugs, natural and synthetic , work on specific neurotransmitter systems of the brain.
Cocaine and amphetamines block reuptake of dopamine
Benzodiaepine tranquilizers work by binding and AUGMENTING the natural action of receptors for the inhibitory neurotransmitter.
SSRIs like Prozac work by inhibiting reuptake of released serotonin
So How To Drugs Work?
Different Drugs have different “receptor sites” in the Brain for the NT.
NT gives a Euphoria at the site in brain.
This is often thought of as a “reward pathway”.
From Synapse to Receptor Site
It is believed that cocaine boosts dopamine release and blocks its reuptake by dopamine transporters. This leaves more dopamine saturating synaptic clefts to overstimulate critical brain sites which cause the sensation of euphoria.
How Cocaine Causes Euphoria
Ecstasy affects neurons that produce the neurotransmitter called SEROTONIN.
Normally, Serotonin, stored in vesicles, is released into synapse at a “progressive rate”. The this chemical is then absorbed by receptors of the adjacent neuron which causes an electrical signal to propagate. The appropriate area of the brain is stimulated.
How Ecstasy Works
When Ecstasy is taken… 1. all of the serotonin in vesicle is released at once. This floods the synapse. 2. Then uptake serotonin receptors are blocked to that Serotonin remains in synapse. Now the NT can work longer on pleasure area of the brain.
Types◦Psychoactive – alters mood or
consciousness; affects neural functioning◦Non-psychoactive – e.g., antibacterial
Classes of psychoactive drugs◦Sedative-Hypnotics
E.g. Barbiturates, Anti-anxiety, alcohol Reduce anxiety (low), sedation (medium), anesthesia
(high)
◦Behavioral Stimulants and Consultants E.g. Amphetamines, Cocaine, Caffeine, Nicotine Increase activity (increase motor activity or counter
fatigue)
Drug Types
Classes of psychoactive drugs◦Narcotic Analgesics E.g., Opium, heroine, morphine, codeine Relieve Pain
◦Antipsychotic Agents E.g., Lithium, haloperidol, reserpine Used to treat schzophrenia
◦ Psychedelics and Hallucinogens E.g., LSD, Marijuana, MDMA (Ecstasy) Alter sensory perception and cognitive processes
Drug Types
Nutt et al. (2007) – The Lancet◦ Two sets of experts rate drugs on dimensions of
harm Physical Harm – acute, chronic, Intravenous Dependence – pleasure intensity, psychological
dependence, physical dependence Social Harm – Intoxication, other social harm, health-
care costs
Drug Harm
At low doses it acts as a stimulant, at higher doses it acts as a sedative.
does not cause a high, but rather, modulates emotions.
Stimulates the amplified release of three neurotransmitters: dopamine, epinephrine and norepinephrine.
What Kind of Drug is Nicotine?
Another group of abused drugs. Amphetamines: synthetic stimulants. Effects: ALERT, less fatiqued or bored and
INCREASED motor activity. Increased heart rate and BP, decreased
appetite. Examples: Methadrine, Speed, Crack. Cocaine Dependence: Tolerance is achieved even after
moderate doses. Long-term users can suffer brain damage similar to Parkinson’s disease.
Central Nervous System Stimulants (Uppers)
Effects:• heartbeat accelerates• blood pressure rises• blood vessels constrict• gastric & adrenal secretions increase
• greater muscular tension• increased motor activity
Stimulants
Ritalin◦ Common treatment of ADHD and ADD.
Ephedrine◦ Found in Chinese herbal tea.◦ “Herbal ecstasy”◦ Common in weight loss and driver stimulant products.
Caffeine◦ The most commonly used psychoactive drug in US.◦ Coffee, tea, cocoa, soft drinks.◦ Does sugar cause psychological disorders?
Stimulant’s (continued)
Repeated use of amphetamines leads to tolerance.
Psychosis is a possible consequence of a person of high doses; a temporary state of severe paranoia; with delusions of persecution and unprevoked violence.
Bottom Line: You can easily get hooked on uppers.
Dependence on Stimulants
Slow nervous system down• alcohol• tranquilizers• barbiturates
Effects -• reduce anxiety• mood changes• slurring of speech• drowsiness, sleep
sedatives - hypnotics
CNS Depressants:
Tranquilizers, Barbituates ( Valium, Librium…Street names..Reds, Ludes for Methaqualude)
Effects: Slow nerve activity, cause relaxation, sleep and relax muscle tension.
Tolerance is achieved quickly. Alcohol and depressants…a deadly
combination…can be.
Depressants (Downers)
A drug made from or chemically similar to opium. Opium comes from poppy plant.
Reduce pain and induce sleep and induce euphoria.
Heroin, Morphine, Darvon, and Demoral, codeine.
Heroin is usually injected and tolerance is achieved easily.
Withdrawal symptoms are severe.
Narcotics (Opiods)
Refers to a group of drugs currently used at all night dance parties
Dangerous by themselves, many are tasteless, odorless and people try to assault or sedate others in cocktails.
Ecstasy ( MDMA), Rohypnol (roofies) and LSD. See list in text.
Club Drugs
Hallucinogens are drugs that dramatically alter perceptions. Some hallucinogens are produced solely by nature. These include psilocybin, found in certain mushrooms ("magic mushrooms" or "shrooms") and mescaline, the chemical found in the peyote cactus. LSD is semi-synthetic, or artificial.
Hallucinogens
LSD Psilocybin (derived from mushroom) Mescaline (component of peyote cactus) PCP, an anesthetic used in veterinary
medicine (Also called Angel dust)
Examples of Hallucinogens
LSD (lysergic acid diethylamide) was invented by a chemist in 1938 by Albert Hofmann.
Trying to create medicine out of a fungus….AND CREATED … LSD. Five years after he created it, Hofmann accidentally ingested the drug and took the first bad trip:
"A demon had invaded me," he said. "[It] had taken possession of my body, mind, and soul."
LSD TRIP may include good experiences like SYNESTASIA and…very often….terrifying experiences….
Hallucinogens
LSD works on 2 parts on the brain the cerebral cortex involved in mood, cognition and perception and the Locus ceruleus involved in sensory perception (site of synethesia)
Hallucinogens
Serotonin is the
NT for this drug
Marijuana, Hashish In a class by itself … CALLED PSYCHEDELIC:
acts as stimulant, depressant, hallucinogen, and narcotic all in one!!
Tetrahydrocannabinol (THC) (Active Ingredient): But over 400 chemicals found; 60 unique to Cannabis plant.
Effects: Relaxation, euphoria, time-perception slowed, laid-back attitude.
Cannabis sativa
THC acts on cannaboidreceptorswhich are found on neurons in many places in the brain. These brain areas are involved in memory (the hippocampus), concentration (cerebral cortex), perception (sensory portions of the cerebral cortex) and movement (the cerebellum, substantia nigra, globus pallidus). When THC activates cannabinoid receptors, it interferes with the normal functioning of these brain areas.
O
OH
tetrahydrocannabinol (THC)
THC , by binding to these receptors, stimulates them to abnormally, release unusually large amounts of dopamine, a NT, into the synapse.
What Does THC DO at When it Binds to the Cannabinoid Receptor?
Many neurons can be activated through the THC pathway.
Complex Pathway.
What Does THC DO at When it Binds to the Cannabinoid Receptor
Distorted perception (sights, sounds, time, touch)
Problems with memory and learning
Loss of coordination
Trouble with thinking and problem-solving
Increased heart rate, reduced blood pressure
Short term Effects Of Marijuana Use
WELL, you get similar addictive results ….. as most psychoaddictive Drugs
BUT BECAUSE THIS STUFF IS USUALLY SMOKED……
Let’s add a few concerns……. If you smoke too much; lots of carcinogens
more than cigarettes! Increases risk for lung cancer
UK in 2009 changed this from C to B category drug WHY???….Increases risk of Schizophrenia by 40% . Large Study done.
Long Term Effects of Marijuana Use
CLUSIONS: Long-term heavy cannabis use in healthy individuals is associated with smaller cerebellar white-matter volume similar to that observed in schizophrenia. Reduced volumes were even more pronounced in patients with schizophrenia who use cannabis. Cannabis use may alter the course of brain maturational processes associated with schizophrenia.
STUDIES SHOW…..
Anabolic steroids are MALE HORMONES.
Promote tissue growth and lead to muscle growth.
Adverse side effects including development of breasts, hair loss, and …yes, CANCER. DARE TO ASK…WHY???
Anabolic Steroids
Cause a quick rush to the brain. Solvent, aerosols, anesthetics, nitrates. Such as
paint thinners, solvents, glue. Loss of inhibition, slurred speech, motor
coordination, loss of consciousness.Can cause serious damage to many organs
including brain, kidneys, heart and liver etc. High conc. Of inhalants can cause suffocation…death
SSD (Sudden Sniffing Death) If person inhales too long or is startled or participates in physical activity- instant death.
Inhalants
T Serotonin is the NT for this drug Hallucinogens produce “Altered States of
Consciousness his is a your sense of body position and movement .
Some drugs distort your sense of proprioception.
You may feel as if you are floating. It can happen with some hallucinogens. Example PCP “angel dust”
Proprioception
Increased responsiveness to same dose of drug◦ More likely with occasional drug use◦ Context is important
Sensitization seems to occur when taken in novel environments
◦ Very long lasting Evidence that sensitization may be due to dendrite
growth
Sensitization
This phenomenon may occur during use of UPPERs ( CNS stimulants).
During drug use the person is in one psychological state and information learned during that state may not be recalled when the drug user is off of the drug.
State Dependence
Perceptual distortions and hallucinations that occur days or even weeks after the drug has been eliminated from the body.
Flashbacks
This is when a person receives an INERT , That is ….no drug…no nothing…inactive ingredient… that doesn’t react with your body.. AND…… ( here’s where it becomes placebo….. YOU GET A RESPONSE from it as if it were an ACTIVE DRUG..
Placebo Effect?
Blood Brain Barrier1. Large molecules do not
pass through the BBB easily.
2. Fat Insoluble molecules do not penetrate into the brain. However, lipid soluble molecules, such as barbituate drugs, alcohol rapidly cross through into the brain.
3. Molecules that have a high electrical charge are slowed.
Allows nurishment to fetus Not Nearly as protective as Blood Brain
Barrier (BBB) as……. Fat INSOLUBLE DRUGS have an EASY
TIME PENETRATING THIS MEMBRANE!
The Placental Barrier
Teratogen- anything, but usually refers to a chemical, that causes developmental damage to a fetus.
Teratogen
Is a complex disorder associated with the idea that one is in the process of becoming addicted to a substance
There are 7 specific criteria that the APA has established for DD.
Drug Dependence
1. Sudden withdrawal2. Rebellion or irritable behavior3. Loss of interest in usual activities4. Decline in school performance5. Sudden change in group of friends6. Changes in sleep or eating habits7. Borrowing or stealing money
Signs of drugs dependence- (in others)
Signs of drugs dependence in yourself
1) Use drug on regular basis?2) Always use it in certain situations? With certain people?3) Is it difficult to stop? 4) Do you need larger doses as time goes
by?5) Do you take it to feel normal?6) Do you go to extreme lengths to get it? Do you put yourself in dangerous
situations?7) Do you hide your use from others?8) Do you scheme to be high when you're
not?9) Do you feel bad if you stop taking it?10) Does it interfere with or guide your
life?
1) Developing TOLERANCE- When a person requires increased amounts of drug to get high.
2) Experiencing Withdrawal- Without drug, person experiences both physical and cognitive symptoms such as tremors, depression etc.
3) Taking drug in larger amounts over time4) Spending a great deal of time acquiring
drug5) Giving up or reducing an important social,
school or work due to substance abuse.6) Continuing to use the substance in spite of
recognizing that it is contributing to a psychological or physical problem.
Criteria For Drug Dependence Established by APA