Chapter 15 Flashcards
Exogenous substances
—from outside the body—
• Neurons process and transmit information through
electrical and chemical signals
• The presynaptic neuron releases an ____________
(internal) substance—
endogenous, a neurotransmitter.
•Routes of Administration
–Ingestion
–Injection
–Inhalation
–Absorption
Pharmacological
Pertaining to the scientific study of drugs
Psychoactive Drugs
Drugs that influence subjective experience and behavior by acting on the nervous system
Drug Metabolism
The conversion of a drug from its active form to a nonactive form
Drug Tolerance
A state of decreased sensitivity to a drug that develops as a result of exposure to the drug
Cross Tolerance
Tolerance to the effects of one drug that develops as the result of exposure to another drug that acts by the same mechanism
Drug Sensitization
An increase in the sensitivity to a drug effect that develops as a result of exposure to the drug
Metabolic Tolerance
Tolerance that results from a reduction in the amount of a drug getting to its sites of action
Functional Tolerance
Tolerance resulting from a reduction in the reactivity of the nervous system (or other sites of action) to a drug.
Withdrawal Syndrome
The illness brought on by the elimination from the body of a drug on which the person is physically dependent
Physically Dependent
Being in a state in which the discontinuation of drug taking will induce withdrawal reactions
Drug Addicts
Those habitual drug users who continue to use a drug despite its adverse effects on their health and social life, and despite their repeated efforts to stop using it.
Contingent Drug Tolerance
Drug tolerance that develops as a reac-tion to the experience of the effects of drugs rather than to drug exposure alone.
Before-and-after Design
The experimental design used to demonstrate contingent drug tolerance; the experimental group receives the drug before each of a series of behavioral tests and the control group receives the drug after each test.
Conditional Drug Tolerance
Tolerance effects that are maximally expressed only when a drug is administered in the situation in which it has previously been administered.
Conditional Compensatory Responses
Physiological responses opposite to the effects of a drug that are thought to be elicited by stimuli that are regularly associated with experiencing the drug effects.
Exteroceptive Stimuli
Stimuli that arise from outside the body
Interoceptive Stimuli
Stimuli that arise from inside the body
Nicotine
The major psychoactive ingredient of tobacco
Drug Craving
An affective state in which there is a strong desire for the drug
Smoker’s Syndrome
The chest pain, labored breathing, wheezing, coughing, and heightened susceptibility to infections of the respiratory tract commonly observed in tobacco smokers.
Buerger’s Disease
Buerger’s disease. A condition in which the blood vessels, especially those supplying the legs, are constricted whenever nicotine enters the bloodstream, the ultimate result being gangrene and amputation.
Teratogen
A drug or other chemical that causes birth defects
Depressant
A drug that depresses the neural activity
Delirium Tremens (DT)
The phase of alcohol withdrawal syndrome characterized by hallucinations, delusions, agitation, confusion, hyperthermia, and tachycardia.
Korsakoff’s Syndrome
A neuropsychological disorder that is common in alcoholics and whose primary symptom is severe memory loss.
Cirrhosis
Scarring, typically of the liver
Fetal Alcohol Syndrome
A syndrome produced by prenatal exposure to alcohol and characterized by brain damage, mental retardation, poor coordination, poor muscle tone, low birth weight, retarded growth, and/or physical deformity.
Cannabis Sativa
The common hemp plant, which is the source of marijuana
THC
Delta-9-tetrahydrocannabinol, the main psychoactive constituent of marijuana
Hashish
Dark corklike material extracted from the resin on the leaves and flowers of Cannabis sativa
Narcotic
A legal category of drugs, mostly opiates
Anandamide
1st endogenous endocannabinoid to be discovered and characterized
Stimulants
Drugs that produce general increases in neural and behavioral activity
Cocaine
A potent catecholamine agonist and stimulant that is highly addictive
Crack
A potent, cheap, smokable form of cocaine
Cocaine Psychosis
Psychotic behavior observed during a cocaine spree, similar in many respects to paranoid schizophrenia
Amphetamine
A stimulant drug whose effects are similar to those of cocaine
Empathogens
Molecules in the presynaptic membrane of dopaminergic neurons that attract dopamine molecules in the synaptic cleft and deposit them back inside the neuron.
Opium
The sap that extends from the seed pods of the opium poppy
Morphine
A relatively weak psychoactive ingredient of opium
Opiates
Morphine, codeine, heroin, and other chemicals with similar structures or effects
Analgesics
Drugs that reduce pain
Harrison Narcotics Act
The act, passed in 1914, that made it illegal to sell or use opium, morphine, or cocaine in the United States
Heroin
A powerful semisynthetic opiate
Physical-Dependence Theories of Addiction
Theories holding that the main factor that motivates drug addicts to keep taking drugs is the prevention or termination of withdrawal symptoms.
Detoxified Addicts
Addicts who have none of the drug to which they are addicted in their body and who are no longer experiencing withdrawal symptoms.
Postive-Incentive Theories of Addiction
Theories holding that the primary factor in most cases of addiction is a craving for the pleasure-producing properties of drugs.
Intracranial Self-Stimulation (ICSS)
The repeated performance of a response that delivers electrical stimulation to certain sites in the animal’s brain.
Mesotelencephalic Dopamine System
The ascending projections of dopamine-releasing neurons from the substantia nigra and ventral tegmental area of the mesencephalon (midbrain) into various regions of the telencephalon.
Substantia Nigra
The midbrain nucleus whose neurons project via the nigrostriatal pathway to the striatum of the basal ganglia; it is part of the mesotelencephalic dopamine system and degenerates in cases of Parkinson’s disease.
Ventral Tegmental Area
The midbrain nucleus of the mesotelencephalic dopamine system that is a major source of the mesocorticolimbic pathway.
Nucleus Accumbens
Nucleus of the ventral striatum and a major terminal of the mesocorticolimbic
Mesocorticolimbic Pathway
The component of the mesotelencephalic dopamine system that has cell bodies in the ventral tegmental area which project to various cortical and limbic sites
Drug Self-Administration Paradigm
A test of the addictive potential of drugs in which laboratory animals can inject drugs into them-selves by pressing a lever.
Conditional Place-Preference Paradigm
A test that assesses a laboratory animal’s preference for environments in which it has previously experienced drug effects.
Relapse
To return to a diseased state after a period of improvement (e.g., to return to addictive drug after a period of voluntary abstinence)
Anhedonia
A general inability to experience pleasure
Positive-Incentive Value
The anticipated pleasure associated with a particular action, such as taking a drug
Hedonic Value
The amount of pleasure produced by an action
Incentive-Sensitization Theory
Theory that addictions develop when drug use sensitizes the neural circuits mediating wanting of the drug—not necessarily liking for the drug.
Drug Priming
A single exposure to a formerly abused drug
what are the 2 classes of endogenous opioid neurotransmitters?
endorphins and enkephalins
what glial cell creates the blood brain barrier?
astrocytes
which area of the brain is blood barrier weak?
area prostema
- a region of the medulla where the blood-brain barrier is weak; allows entry of toxic substances that induce vomiting
dose-response curve
The principle that the effect of a certain drug depends on the dose or concentration of that drug.
- after a certain point, increasing the dose does not increase effects
therapeutic index
the ratio between the toxic and therapeutic concentrations of a drug
- margin of safety
- effectiveness
what are the two types of tolerance?
metabolic tolerance:
- organ systems become more effective at eliminating the drug
functional tolerance:
- target tissue (site of action) may show altered sensitivity to the drug
- more common
does tolerance affect every drug reaction?
no; it can be for only some effects
- e.g. sedation but not depressed breathing
drugs can impact: (8)
- Synthesis
- Storage
- Release
- Postsynaptic receptors
- Inactivation
- Reuptake
- Degradation
- Presynaptic receptors
Agonist
enhance the effect of a neurotransmitter
e. g.:
- stimulate release of NT
- stimulate postsynaptic receptors
- block auto-receptors
- block reuptake
Antagonist
inhibits the effect of a neurotransmitter
e. g.:
- block postsynaptic receptors
- stimulate auto-receptors
- inhibit release of NT
- prevent storage of NT in vesicle
alcohol neurological effects
GABA agonist: increases the activity of the GABA receptor causing the brain to be inhibited resulting in diminished arousal
parts of the brain that stop inappropriate behavior are also diminished which is why behavior seems to be less inhibited
also increases levels of dopamine
alcohol physiological effects
physiological effects
- Dilates blood vessels in the skin (skin turns pink and feels warm)
- Inhibits antidiuretic hormones (loss of body water through increased urination)
alcohol behavioral effects
- slow reaction time
- decreased hand-eye coordination
what does alcohol depress?
- Sympathetic nervous system (breathing and heartbeat)
- REM sleep
Opiate neurological effects
Endorphin agonist: Binds to opioid receptors and releases endorphins
- stimulates the ventral tegmental area
- very addicting
Opiates physiological effects
- small pupils
- lower coordination of digestive activity (slow digestion, constipation)
- reduces sex drive/hormones
ventral tegmental area
stimulates amygdala for pleasure and reward center
Opiates behavioral effects
- relieves pain (analgesic)
- euphoria
Alcohol withdrawal symptoms
- headaches
- vomiting
- hallucinations
- tremors
- convulsions/seizures
nicotine neurological effects
- releases dopamine in the nucleus accumbens
- acetylcholine agonist (arousal and cognitive enhancement)
nicotine behavioral effects
- muscle tremors
- bad reflexes
Nicotine withdrawal
- anxiety
- insomnia
- sudden decrease in dopamine in NA; can be related to relapse due to cravings
which neurotransmitter plays a big role in drugs?
dopamine
- in rewarding effects of addictive drugs and natural reinforcers.
incubation of drug craving
cues presented soon after drug withdrawal are less likely to elicit craving and relapse than cues presented later
Reuptake
process by which neurotransmitters are taken back into the synaptic vesicles
THC neurological effects
- THC has a stimulating effect on dopamine in the nucleus accumbens
- binds to the endogenous CB1 cannabinoid receptor
THC psychological effects
Depressant:
- disinhibition
- euphoria
Hallucinogenic:
- amplifies sensitivity to colours, sounds, tastes, smells
- also impairs perceptual skills, motor skills and reaction time
drug self-administration paradigm
A test of the addictive potential of drugs in which laboratory animals can inject drugs into themselves by pressing a lever.
