Your Brain on Drugs?!. Drug Basics A drug is any chemical put into the body that changes mental...
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Transcript of Your Brain on Drugs?!. Drug Basics A drug is any chemical put into the body that changes mental...
Your Brain on Drugs?!
Drug Basics
•A drug is any chemical put into the body that changes mental state or bodily function.
•How a drug is taken can make a huge a difference in its effect.
•The length of time a drug effects the CNS can vary tremendously.
•The effects of drugs can change with time, as our bodies adapt to the drug. This is called tolerance.
Drug Basics
Drugs work by binding to receptors on the surface of cells.
•Drugs that activate receptors when bound are called agonists.
•Drugs that deactivate receptors when bound are called antagonists.
Drug Basics
Drug Basics
How do drugs get into the body?
•Cutaneous absorption
•Mucus membranes
•Ingestion
•Inhalation
•Injection
Drug Basics
Drug Basics
Where do drugs go in the body?
•Once in circulation, drugs go to all tissues easily.
•Only psychoactive drugs can effect the brain.
•Drugs that are not removed from the body are stored in fat tissue.
•The liver is the organ that breaks down drugs for removal from the body.
Drug Basics
Drug Basics
Pathways to drug tolerance:
•Increased enzyme production by liver (alcohol)
•Removal of receptors to balance stimulation (nasal decongestants)
•Body preemptively counteracts drug by unconscious expectation (heroin)
Drug Basics
Drug Basics
Addiction vs. Dependence
•Addiction is the repetitive, compulsive use of a substance despite negative consequences to the user. (AKA Psychological Dependence; Dopamine)
•Physical dependence results from a change in cell function such that organs cannot function without the drug. (ex: seizures during alcohol withdrawl)
Drug Basics
Drug BasicsAlcohol
Drug Class:
Sedative hypnotic
Individual Drugs:
beer, wine, liquor
The Buzz: Pleasure and
relaxation during
first ~30min,
followed by
sedation
The BuzzKill: Alcohol poisoning; chronic abuse can lead to psoriasis of the liver, stomach ulcers, increased risk of heart disease and cancer, brain shrinkage (decrease in memory, problem solving, concentration); diuretic (hangover)
Drug BasicsAlcohol
Getting In: Absorbed by blood vessels in stomach and small intestines (greater alcohol content=faster absorption)
Getting Out: Primarily metabolized by liver (alcohol dehydrogenase); products are excreted in urine; intermediate product, acetaldehyde, causes nausea
Brain Effects: Activates GABA receptors (inhibitory); deactivates glutamate receptors (excitatory); Increases release of dopamine (addictive)
Drug BasicsCaffeine
Drug Class:
Stimulant
Individual Drugs:
coffee, soft drinks
The Buzz: Low-moderate doses=increased alertness and ability to concentrate; high doses=nervousness, agitation
The BuzzKill: diuretic; caffeine poisoning (tremors, nausea, rapid heart rate, confusion; fatal overdose is rare)
Drug BasicsCaffeine
Getting In: Absorbed by blood vessels in stomach and (primarily) small intestines
Getting Out: Metabolized by liver; products are excreted in urine
Brain Effects: Inhibits adenosine (inhibitory)
Effects on Other Organs: Irregular heart beat; raise cholesterol (unfiltered coffee); activate kidneys; irritate stomach; increase breathing rate, relax bronchioles
Drug BasicsEnactogens
Drug Class:
Enactogen
Individual Drugs:
ecstasy
The Buzz: Produce a sense of energy and alertness like amphetamines; experience good feelings for all those around them and strong empathy
The BuzzKill: Jitteriness and teeth-clinching; increased heart rate, blood pressure, and body temperature can lead to death when combined with physical activity or stimulants; chronic abuse damages neurons
Drug BasicsEnactogens
Getting In: Absorbed by blood vessels in gastrointestinal tract; usually taken orally
Getting Out: Metabolized by liver in 3-6 hours
Brain Effects: Floods synapses with dopamine (addicitive), norepinephrine (excitatory), serotonin (hallucination); chronic use leads to irreparable brain damage
Drug BasicsHallucinogens
Drug Class: Hallucinogens
Individual Drugs: LSD, mushrooms (psilocybin), peyote (mescaline), PCP (phencyclidine), Special K (ketamine)
The Buzz: Indivdual experience vary widely; low doses=feelings of detachment from surroundings, mood swings, altered sense of space and time; high doses=hallucinations, out of body experience
The BuzzKill: LSD, mushrooms, and peyote=bad trip can produce extreme anxiety, lack of awareness of surroundings can lead to injury or death; PCP and Special K=death by overdose
Drug BasicsHallucinogens
Getting In: Absorbed by blood vessels in gastrointestinal tract; usually taken orally; inhalation
Getting Out: Liver breaks down drugs; could take 1 hour to several hours, depending on the drug
Brain Effects: All=floods synapses with serotonin (hallucination); PCP and Special K=blocks glutamate receptors (excitatory); PCP also has amphetamine effects
Drug BasicsInhalants
Drug Class: mixed
Individual Drugs: nitrites, whippets (nitrous oxide), paints, fuels
The Buzz: mild euphoria; smooth muscle relaxation; reduction of pain; hallucinations (solvents)
The BuzzKill: muscular incoordination; nausea, vomiting; heart palpations; loss of consciousness; suppression of breathing; death-for real!
Drug BasicsInhalants
Getting In: Inhalation: absorbed by capillaries in the lungs
Getting Out: Liver breaks down some drugs; others are inert and lose their effect shortly after exhalation
Brain Effects: Details about brain effects are unknown; inhibit ability of nerves to conduct impulses; neurotransmitter, GABA, involved
Drug BasicsMarijuana
Drug Class: marijuana
Individual Drugs: marijuana, hash
The Buzz: experiences vary: relaxation, mood elevation, hillarity, contemplative silence, sedation
The BuzzKill: anxiety; increase heart rate; impair judegement; overdose is virtually impossible
Drug BasicsMarijuana
Getting In: Inhalation: absorbed by capillaries in the lungs; ingestion
Getting Out: Liver breaks down THC slowly; THC stored in fat tissue for weeks, metabolic products are also mildly psychoactive
Brain Effects: THC binds to cannabinoid receptors in hippocampus (anandamine); leads to deficits in memory formation
Effects on Other Organs: depress immune system; anti-nausea/appetite stimulant; decreased lung capacity; reproductive effects
Drug BasicsNicotine
Drug Class: stimulant
Individual Drugs: tobacco
The Buzz: increases attention and concentration; calming effect
The BuzzKill: dizziness; weakness; nausea; chronic use is implicated in increased incidence of depression overdose is rare
Drug BasicsNicotine
Getting In: Inhalation; absorption in mucus membranes
Getting Out: Liver breaks down nicotine into cotinine and nicotine-N-oxide, which are excereted in the urine after ~30 min
Brain Effects: Excites neurons; increases cell-cell signaling; acetylcholine agonist (memory)
Effects on Other Organs: strongly associated with lung disease, atherosclerosis, heart attack
Drug BasicsOpiates
Drug Class: opiate analgesic
Individual Drugs: opium, heroin, morphine, codeine, hydrocodone
The Buzz: rush of euphoria; dreamy, pleasant state; little sensitivity to pain
The BuzzKill: constipation; post-high crash; risk of lethal overdose is real;
Drug BasicsOpiates
Getting In: Inhalation; ingestion; absorption in mucus membranes; intravenous injection
Getting Out: Liver breaks down opiate in ~2-6 hours; opiate antagonist naxolone
Brain Effects: Opiates bind to endorphin-receptors, which would not naturally be so stimulated; building tolerance is common
Effects on Other Organs: negatively effects reproductive system
Drug BasicsSteroids
Drug Class: anabolic steroids
Individual Drugs: testosterone
The Buzz: rush of euphoria (hours after taking); increased energy and combativeness
The BuzzKill: chronic use can lead to heart attack, stroke
Drug BasicsSteroids
Getting In: Ingestion; intravenous injection
Getting Out: Liver breaks down steroids
Brain Effects: Significant brain effects are unknown
Effects on Other Organs: leads to increased muscle mass; general increase in male traits; shrunken testicles
Drug BasicsStimulantsDrug Class: stimulants
Individual Drugs: cocaine, crack, methamphetamine, Ritalin, ephedrine, bath salts
The Buzz: rush of energy; alertness; talkativeness; general sense of well-being
The BuzzKill: increased heart rate, blood pressure, breathing rate; seizures; cardiac arrest; lethal overdose
Drug BasicsStimulants
Getting In: Ingestion; inhalation; absorption by mucus membranes
Getting Out: Liver breaks down drugs (cocaine/crack~1-2 hrs; Meth/ephedrine~2-4 hrs)
Brain Effects: Inhibit reuptake of monoamine neurotransimtters (users feel compelled to engage in repetitve activity); increase epinephrine/norepinephrine (fight or flight); release of dopamine (addictive); release serotonin (decrease appetite, release hormones, raise body temperature)
Effects on Other Organs: Cocaine is used as a local anesthetic. All produce fight-or-flight response
Drug BasicsReference
Kuhn, Swartzwelder, and Wilson. Buzzed: The Straight Facts about the Most Used and Abused Drugs, from Alcohol to Ecstacy. New York: W.W. Norton & Company, Inc., 1998.