biopsych exam 2 (5-7)

What makes drugs addictive?

What makes drugs addictive?

Their effect on the brain.

gaba

most prevalent inhibitory neurotransmitter

Psychoactive Drugs

Medicine or substances that changes body's functioning with psychological effects.

Agonists

Mimic/enhance the effects of a neurotransmitter.

ndma receptor agonists

-inhibit glutamate

-dissociation

-ketamine (special k), phencyclidine (pcp, angel dust, crystal)

Antagonists

occupy a receptor without activating it or decrease availability of neurotransmitter.

-Relies on an addict’s motivation to quit and willingness to comply with a regimen of a medication that provides no pleasure

-naltrexone & naloxone.

Addiction

preoccupation with obtaining a drug, compulsive use of it in spite of adverse consequences, and high tendency to relapse after quitting.

Withdrawal

negative reaction when drug is stopped; due to NS's adaptation to drug. Typically has opposite effects to drug.

Dependence

need to keep taking a drug to avoid withdrawal; physical and psychological dependence have physiological basis.

-Physical dependence: symptoms like headache, difficulty breathing, and racing heart
-Psychological dependence: symptoms like anxiety, depression, and insomnia

Tolerance

person becomes less responsive to drug and requires more of drug to get same effects; compensatory adaptation.

Opiates

drugs derived from opium poppy;

-analgesic (remove pain),

-hypnotic (induce sleep),

-euphoric (sense of ecstasy) effects.

-opium

-morphine (still used today)

-codeine

-paregoric and laudanum

Opioids

not directly derived from opium but have same endogenous receptors.

-Oxycodone/OxyContin

-heroin (from morphine)

Heroin

Highly soluble in lipids; passes blood brain barrier easily. This increases addictive potential (3x more addicitve than morphine)

• high likelihood of relapse (lifelong condition)

• overdose likely

• relaxation, chills, positive mood

heroin withdrawal

• bad flu

• agitation, fever, depression

ectothermic

-snakes, lizards

-behavior to adjust temp

endothermic

-mammals, birds

-energy to adjust temp

ventral tegmental area

part of midbrain, source of dopamine neurons in mesolimbic pathway

Conditioned tolerance

associated with the person's drug-taking surroundings/circumstances. Taking a normal dose in diff. neighborhood can result in overdose.

Endogenous Endorphins

body's own neurotransmitters for receptors opioid drugs act on; our own opioids.

Depressants

drugs that reduce CNS activity; sedatives (calming), anxiolytic (reduce anxiety), and hypnotic substances.

-alcohol

-barbiturates

-benzodiazepines

Alcohol

most commonly abused; aka ethanol. acts at brain sites to produce euphoria, anxiety reduction, sedation, motor incoordination, cog. impairment.

-moderate use gives social benefits (disinhibitor).

-moderate to high doses amygdala cant tell diff between threat and neutral stimuli

-blunt activity of amygdala; reduced glutamate and increased GABA.

-bac 0.08 cant drive

-bac 0.30-0.40 life threatening

stimulating these induce drinking in seconds

-sfo

-ovlt

-mnpo

4 areas in our hypothalamus control our
metabolism and our eating/fasting behavior:

ARC, LH, PVN, VMH

Delirium Tremors

severe reaction to alcohol withdrawal that results in hallucinations, delusions, confusion, and seizures & possible death.

Fetal Alcohol Syndrome (FAS)

Characterized by intellectual impairment, hyperactivity, lack of focus, low weight/height, facial abnormalities in children of mothers who consumed alcohol during pregnancy.

Barbiturates

drugs that in small amount act selectively on higher cortical centers. Frequently used to treat insomnia and prevent seizures.

-low doses produce talkativeness and high social interaction.

-high doses are sedative and hypnotic.
- tolerance lead to increase dosage; trigger addictive symptoms.

Benzodiazepines

drugs that act at benzodiazepine receptor on GABA. ex: Valium, Klonopin, Xanax, Rohypnol.

-lower anxiety and reduce stress.

-produce sedation and muscle reaction.

GABA Receptor Complex

Inhibitory; 5 receptor sites (alcohol, steroids, barbiturates, & benzodiazepines). Very dangerous to mix alcohol with barb. & benz.

Stimulants

drugs that activate CNS to produce arousal, increased, alertness and elevated mood.

-cocaine

-amphetamines

-nicotine

-caffeine

Cocaine

euphoria, decreases appetite, increases alertness, and relieves fatigue. ex: powder, pure smoked (freebase), and crack (smoked vapor).

-blocks serotonin and dopamine

produces reuptake euphoria & excitement.
- removes inhibition of cortex lower structures.
- dampens fetus' eventual IQ, language development, focus

Amphetamines

group of synthetic drugs that produce euphoria and increase concentration. cant tell difference between this and cocaine.

Methamphetamines

among the most powerful of these; aka meth, speed, crank, crystal, ice (freebase).

• dull appetite, reduce fatigue, increase alertness (popular w/ students).

• chronic use increase risk of psychotic symptoms.
  - long term use reduces gray matter, limbic tissue, & hippocampus tissue

Bath Salts

deceptive labeling used to disguise designer drug. Causes psychosis, delirium, violence, and lethal physical effects.

Nicotine

primary psychoactive & addictive agent in tobacco. Ingested by smoking, chewing, inhaling.

• stimulating effect by activating nACh receptors.

• withdrawal=anxiety, headache, drowsiness, lightheadedness

• leading preventable cause of death

• relaxing, tranquilizing sensation; receptors are desensitized.

Caffeine

produces arousal, increased alertness, and decreased sleepiness. Most widely consumed psychoactive in the world 85% of ppl

• may be lethal if consumed at high rates 72 cups

• withdrawal-headache, fatigue, anxiety, shakiness, craving

Psychedelics

compounds that cause perceptual distortions in the user; used to expand senses & alter consciousness.

-LSD, psilocybin/psilocin, DMT, peyote

-many are designer drugs

Designer Drugs

synthetic drugs which are created from chemicals rather than derived natural ingredients - makes production hard to illegalize.

Serotonergic Psychedelics

stimulate serotonin receptors to produce sensory distortions, repetitive geometric shapes, intense colors, and hallucinations.

-lsd, psilocybin, dmt

Catecholaminergic Psychedelics

resemble neurotransmitters such as epinephrine, norepinephrine, and dopamine; has amphetamine-like properties and psychedelic effects.

-mescaline, ecstacy/molly, 2c-b

effects of mdma

• psychomotor stimulant (high energy, sociability & sexual arousal).

• cause hyperactivity and hyperthermia

• hallucinatory effects.

• high use can be toxic to serotonergic neurons.

• crash later

NMDA Receptor Agonists

inhibit the nmda type of glutamate receptor; produces disorientation and hallucinations.

• similar symptoms to schizophrenia.

• ex: ketamine, phencyclidine (PCP, angel dust).

Marijuana (THC)

of the plant cannabis; usually consumed by smoking or mixing into food. Is a cannabinoid (2-AG).

• impaired cognitive function (time sense, perception, memory, motor skills).

• smaller hippocampus and amygdala

• chronic use diminishes dopaminergic activity.

• impaired white matter connectivity.

Reward

positive effect an object/condition has on user; causes pleasure & repeated behavior.

Mesolimbic Pathway

important reward circuit; dopamine releasing neurons. originates in ventral tegmental area and connects to nucleus accumbens.

-nucleus accumbens

-ventral tegmental area

Nucleus Accumbens

target of mesolimbic pathway reward circuit; combines judgements from MDS to determine drug-seeking behavior.

-all addictive drugs increase dopamine here

-similar to effects of food, water, sex

Brain Stimulation Reward

electrical activation of Mesolimbic Pathway replicated in experimental setting; will seek this kind of electrical stimulation.

-all addictivevdrugs end in stimulation of the nucleus accumbens and increased dopamine
transmission

Mesocorticolimbic Dopamine System

consists of VTA and brain regions receiving dopamine projections.

MDS in Brain Structures

• nucleus accumbens: judgments.

• prefrontal cortex: goals and values.
  - hippocampus: memories of drug use.
  - amygdala: conditioned associations/emotional info.

Hypofrontality

reduced activity in frontal regions; control working memory, behavioral inhibition, & response to environment.

Detoxification

allowing body to cleanse itself of drug residues; 1st step in quitting drug use.

Agonist Treatment

replace addicting drug with another drug that has similar effect. ex: methadone.

Aversive Treatments

cause a negative reaction when person takes the drug; taste bad or ill.

-antabuse, silver nitrate

Antidrug Vaccines

stimulate immune system to make antibodies that degrade drug.

Comorbidity

addiction often appears in combo w/mental or emotional disorders; can complicate rehab.

Type 1 Alcoholic

late onset; begin after 25; nonviolent; feel guilt.

Type 2 Alcoholic

early onset; begin at early age; violent; don't feel guilt; majority male.

Motivation

set of factors that initiate, sustain, & direct behaviors.

Instinct

complex behavior; automatic, unlearned, unmodifiable.

Drive Theory

body maintains a condition of homeostasis (drive - an aroused cond.)

Homeostasis

A tendency to maintain a balanced or constant internal state.

Incentive Theory

motivation by external stimuli, not just internal.

Arousal Theory

people behave in ways that keep them at preferred level of stimulation.

Set Point

point of homeostasis to which system returns (body temp, fluid levels, energy reserves).

Preoptic Area

in hypothalamus; contains warmth/cold-sensitive cells (either temp. of blood flow or input). ex: panting, sweat, shivering, changing blood flow, building fat reserves.

Hypovolemic Thirst

occurs when blood volume drops bc of loss of extracellular water; occurs w/osmotic.

Osmotic Thirst

occurs when fluid content decreases in body's cells; can occur independently.

Subfornical Organ (SFO) & Organum Vasculosum (OVLT)

• regulates internal water balance.

• osmoreceptor

Median Preoptic Nucleus (MnPO)

integrates info from SFO and OVLT.

Satiety

satisfaction of appetite.

Taste Primaries

sour, sweet, bitter, salty, umami

Sensory-Specific Satiety

behavioral pattern that more a person eats of specific item, the less appealing it becomes.

Learned Taste Aversion

avoidance of foods associated w/ illness or poor nutrition.

Digestive Process

• begins in mouth; food is broken down w/saliva & teeth.

• stomach mixes food w/gastric juices.

• food releases to intestine.

• duodenum breaks food down to absorb.

Area Postrema

outside of blood brain barrier; induces vomiting of toxins.

Absorption Phase

few hours after meal; body lives off nutrients arriving from digestive sys; glucose levels rise; insulin released; glycogen is made.

Fasting Phase

blood glucose drops and body falls back on its energy stores; stop secreting insulin; start secreting glucagon (glycogen-->glucose).

Arcuate Nucleus (ARC)

hypothalamic center for food intake control; info abt nutrient levels.

Lateral Hypothalamus (LH)

initiates eating & controls aspects of feeding behavior and metabolic responses.

-Controls chewing and swallowing, salivation,
gastric juice secretion, insulin production, and
cortical arousal

Paraventricular Nucleus (PVN)

regulates eating and metabolic processes.

Body temperature, fat storable, cellular
metabolism

Ventromedial Hypothalamus (VMH)

produces satiety and increases metabolism.

Ghrelin

hunger hormone; synthesized in stomach & released into bloodstream during fasting; anticipatory; stim. growth hormone release.

Cholecystokinin (CCK)

peptide hormone; satiety signal; released by stomach/small intestine as food passes into duodenum; limits meal size.

Peptide YY3-36 (PYY)

released in intestine in response to food, suppresses appetite over long period of time.

Leptin

secreted by fat cells that inhibits eating; reduces meal size & total daily intake.

Obesity

causes: diet & activity levels, sleep deprivation, genetic influences.

Anorexia Nervosa

starving disease; individual restricts food intake to maintain weight at threatening low level. consists of restrictors and binge-purgers.

• loss of ovulation, lost muscle mass, heart damage, reduced bone density.

Bulimia Nervosa

involves weight control, but behavior is limited to binging & purging.

• normal weight or overweight body type.

• heart problems, diabetes, damage to esophagus, gums, teeth, electrolyte deletion, dehydration.

Binge-Eating Disorder

individual frequently eat large amount of food during a short period of time; feel they cannot control what/how much they eat.

Sex as a Motivation

• ensures survival of species, not individual.

• arousal & satiation.

• entensive hormonal involvement.

• control linked to spec. brain structures.

Excitement Phase

phase 1; period of arousal/preparation for intercourse (increased heart rate, respiration rate, low blood pressure, muscle tension).

Plateau Phase

increase in sexual arousal levels off.

Orgasm

brief, but intense experience of pleasure.

Resolution

period of quiet after return to homeostasis w/other drives (muscles relax, drop in blood pressure & excitement).

Androgens

class of hormones responsible for a number of male characteristics and functions.

Testosterone

type of androgen; serves as the major sex hormone in males; females produce small amounts as well.

Estrogen

class of hormones responsible for a number of female characteristics and functions; males produce small amounts as well.

Progesterone

made in adrenal glands & testes of males; makes testosterone for men; controls reproduction (receptivity & desire) for women.

Oxytocin

in hypothalamus, released by pituitary; promotes sexual arousal, social bonding, and intensity of pleasure (smooth muscle contractions of orgasm & milk ejection during breastfeeding).

Castration

removal of gonads; results in loss of sexual motivation and functioning.

Hypogonadism

disorder where little or no hormones are produced by ovaries or testes; reduced sexual behaviors.