Physio Psych Ch 3

Addiction is defined as

"substance use disorder" (SUD) .•Takes multiple forms •Varies from mild to severe •Diagnosis requires sustained problems and patterns that interfere with daily functioning

Four major models of drug abuse:

1.Moral model—abuser lacks moral character or self-control 2.Disease model—abuser requires medical treatment 3.Physical dependence model—abusers use drugs to avoid withdrawal symptoms like dysphoria 4.Positive reward model—drug use is a behavior controlled by positive rewards

Which of the following changes in the neurotransmitter systems has been found to be associated with Alzheimer's disease?

A widespread loss of cholinergic neurons

Which of the following is most likely to be the action of an antidepressant drug?

Blocking enzymes responsible for the breakdown of transmitters

Identify a similarity between a selective serotonin reuptake inhibitor (SSRI) and a serotonin-norepinephrine reuptake inhibitor (SNRI).

Both block the reabsorption of transmitter by the presynaptic neuron.

The active ingredient in Botox is the ____________ toxin.

Botulinum

How do neurons counteract the effect of an antagonist drug?

By up-regulating the number of receptors

A person with an anxious disposition calms down after eating cannabis cookies. Which of the following active ingredients in cannabis is most likely to be responsible for this reduction in anxiety?

Cannabidiol (CBD)

Which of the following occurrences in a neuron are most likely to explain an increase in the production of a neurotransmitter? (Select all that apply.)

Changes in gene expression The binding of metabotropic receptors by signaling chemicals The activation of the two-step second messenger signaling process

__________ was used in foods and as an anesthetic but is highly addictive and has serious side effects.

Cocaine

Which of the following problems are most likely to be caused by the heavy use of cannabis? (Select all that apply.)

Cognitive decline, Respiratory problems

Types of neurotransmitters:

Amino acid neurotransmitters—GABA, glutamate •Peptide neurotransmitters (neuropeptides)—oxytocin, vasopressin •Amine neurotransmitters—acetylcholine, dopamine, serotonin •Gas neurotransmitters—nitric oxide, carbon monoxide

A drug that relieves the symptoms of depression is known as a(n) ____________

Antidepressant

Which of the following are the best-known active ingredients of cannabis? (Select all that apply.)

Delta-9-tetrahydrocannabinol (THC), Cannabidiol (CBD)

cannabis effects

Effects vary—relaxation, mood alteration, stimulation, and paranoia •Heavy use can cause respiratory problems, addiction, cognitive decline •Adolescent use of marijuana may increase risk of developing schizophrenia

T/F Caffeine stimulates adenosine receptors.

False

T/F Cross-tolerance for drugs in the opiate category develops because the body develops metabolic tolerance toward a drug of the category.

False

T/F When plotted as a graph, the dose-response curve (DRC) of a drug typically is an exponential (J-shaped) curve.

False, usually S shaped

Which of the following drugs are examples of a selective serotonin reuptake inhibitor (SSRI)? (Select all that apply.)

Fluoxetine, Citalopram

Alcohol acts on

GABA receptors and dopamine-mediated reward systems.

Which of the following statements are true of the mesostriatal pathway? (Select all that apply.)

It is a major dopaminergic projection. It projects axons to regions of the basal ganglia.

Identify the true statements about the mesolimbocortical pathway. (Select all that apply.)

It plays an important role in learning. It originates in the midbrain.

Many peptides act as neurotransmitters:

Opioid peptides mimic opiate drugs such as morphine and reduce the perception of pain. •Peptides discovered in the gut are also made by neurons in the spinal cord and brain (substance P, cholecystokinin). •Peptide hormones, such as oxytocin and vasopressin, contribute to memory and pair-bonding.

Which of the following factors determines the characteristics—such as the specific neurotransmitter it recognizes and the type of ions that it selectively conducts—of each subtype of ionotropic receptors?

The combination of subunits that make up the receptor

Which of the following is an effect of drugs, such as monoamine oxidase inhibitors, that block transmitter degradation?

The effect of transmitter increases, and it remains active for a longer time.

In which parts of the brain are the effects of compounds like delta-9-tetrahydrocannabinol (THC) mediated? (Select all that apply.)

The substantia nigra The cerebellar cortex The hippocampus

Which of the following statements is true of G protein-coupled receptors (GPCRs)?

They can be activated extracellularly.

Which of the following statements are true of drugs that block autoreceptors? (Select all that apply.)

They cause the cells to release more transmitter than usual. They prevent the presynaptic neuron from receiving its normal feedback.

Which of the following is true of compounds, such as tetrodotoxin, that block sodium channels?

They prevent axons from firing.

Drugs may alter the presynaptic neuron:

Transmitter production—drugs may block synthesis enzymes, axonal transport of raw materials, or the ability to store transmitter •Transmitter release—drugs can block action potentials by blocking ion channels •Autoreceptorscan be affected by drugs. •Transmitter clearance—a drug may block reuptake of transmitter or block enzymes

Alzheimer's disease

Widespread loss of these neurons

insula

a brain region within the frontal cortex.

endogenous(internal) substance

a neurotransmitter

Second-generation antipsychotics

act on receptors in addition to or other than D2receptors and may relieve symptoms resistant to typical antipsychotics.

When a drug activates the receptor, it is acting as an

agonist

Metabotropic receptors

alter chemical reactions in the cell

Hallucinogens

alter sensory perception and produce unusual experiences through diverse neural actions.

Synthetic stimulants like ________ have a two-step mode of action on monoamines.

amphetamine oAmphetamine causes a larger-than-normal release of transmitter at axon terminals oAmphetamine also interferes with the breakdown of the transmitter. oProlonged use leads to symptoms that resemble those of schizophrenia or brain damage.

Endocannabinoids

analogs of marijuana produced in the brain, such as anandamide

When a drug binds a receptor without activating it and also blocks it, is an

antagonist

Ligand

any substance that binds to a receptor

First-generation antipsychotics (neuroleptics)

are a class of drugs that alleviate symptoms of schizophrenia, typically by blocking dopamine D2receptors.

A(n)______________ is a receptor for a synaptic transmitter that is located in the presynaptic membrane and tells the axon terminal how much transmitter has been released.

autoreceptor

Alcohol's effects are

biphasic—an initial stimulant phase, followed by a depressant (inhibited neural activity) phase.

Tricyclic antidepressants

block reuptake of serotonin and norepinephrine.

Presynaptic adenosine receptors normally reduce transmitter release but are blocked by ________, resulting in increased transmitter release.

caffeine

The three kinds of opioid receptors

delta, kappa, and mu—are all metabotropic receptors.

The chief active ingredient in cannabis is:

delta-9-tetrahydrocannabinol (THC).

A(n) __________ is a formal graph of a drug's effects (on the y-axis) versus the dose given (on the x-axis). (The correct answer consists of three words and also exists in the form of acronym.)

dose-response curve

Endogenous opioids

enkephalins, endorphins, and dynorphins—are peptides produced in the brain.

bioavailable

free to act on the target

Exogenous substances

from outside the body—have been used for ages to change the functioning of the brain and body.

Down-regulation

in response to an agonist—fewer receptors

Up-regulation

in response to an antagonist—more receptors

Noradrenergic neurons are found

in the locus coeruleus and the lateral tegmental area.

Stimulants increase nervous system activity by

increasing excitatory input or decreasing inhibitory activity.

A dose-response curve (DRC)

is a graph of the relationship between drug doses and the effects.

MDMA(Ecstasy)

is a hallucinogenic amphetamine derivative—it stimulates visual cortical serotonin receptors but also changes levels of dopamine and prolactin.

Dopamine

is important for many aspects of behavior.

Norepinephrine

is important in the control of many behaviors ranging from alertness to mood to sexual behavior.

Disruption of cholinergic pathways in rats interferes with

learning and memory.

The mesolimbocorticalpathwayoriginates in the ventral tegmental area (VTA) and is important for

learning shaped by positive reinforcement.

Selective serotonin reuptake inhibitors (SSRIs)

like Prozac or Celexa, act specifically at serotonergic synapses.

The disease model of substance abuse takes the view that the person who abuses drugs requires ___________ rather than punishment.

medical treatment

Over time, chronic consumers of alcohol have to consume more alcohol to feel its intoxicating effects. One of the reasons for this tolerance to alcohol is that their livers develop the capacity to quickly degrade the alcohol and remove it from the bloodstream. The given scenario exemplifies ______________.

metabolic tolerance

Molecules bind to

neurotransmitter receptors in the membrane of the postsynaptic cell.

Many addictive drugs cause dopamine release in the

nucleus accumbens

Biotransformation

produces active metabolites that may produce side effects

Ionotropic receptors

quickly change shape and open or close an ion channel when the transmitter molecule binds.

Receptor proteins

recognize transmitters and their mimics.

tolerance

reduced efficacy of the drug

Pharmacokinetics

refers to all the factors that affect the movement of drugs from their entry into the body to their exit from the body

Action potentials cause vesicles to

release neurotransmitter into the synaptic cleft.

Nicotine, from tobacco, acts as a...

stimulant

LSD (acid)

strongly activates serotonin 5-HT2A receptors in the visual cortex.

Functional tolerance

target tissue may alter its sensitivity to the drug by changing the number of receptors

Efficacy (intrinsic activity)

the ability of a bound ligand to activate the receptor.

Many cholinergic neurons are found in

the basal forebrain.

binding affinity

the degree of chemical attraction between a ligand and a receptor

Action potentials reach the axon terminal

the presynaptic side of a synapse.

The ____________ of a drug refers to the separation between useful doses of the drug and dangerous doses.

therapeutic index

Blood-brain barrier

tight junctions between the cells of blood vessels in the CNS prevent the movement of large molecules; can limit drug availability

Cross-tolerance

tolerance to one drug is generalized to other drugs in its class

Acetylcholineplays a major role in

transmission in the forebrain

Antidepressant drugs

used to treat disturbances of mood called affective disorders.

Drugs may alter postsynaptic systems:

•Can affect transmitter receptors: Receptor antagonists block postsynaptic receptors from being activated. Receptor agonists bind to receptors and activate them. •Can alter intracellular postsynaptic processes:oReceptor up-or down-regulation Activation of second-messenger systems Activation of genes

Anxiolytics

•Depressants are drugs that reduce nervous system activity. •Barbiturates, early anxiolytics and sleep aids, depress nervous activity—addictive and easy to overdose on. •Specific anxiolytics, such as benzodiazepines, act as agonists on GABAA receptors and enhance the inhibitory effects of GABA.

The most common transmitters in the brain are amino acids:

•Glutamate—most widespread excitatory transmitter AMPA and NMDA receptors •Gamma-aminobutyric acid (GABA)—most widespread inhibitory transmitter GABA receptors—ionotropic; inhibitory; allow Cl-ions into the cell

Which of the following plants is the source of the drug commonly known as marijuana?

The Cannabis sativa plant

Which of the following category of drugs is the earliest antidepressant drug category?

Monoamine oxidase (MAO) inhibitors

Which of the following types of antidepressants act by blocking enzymes that breakdown transmitters such as dopamine, serotonin, and norepinephrine?

Monoamine oxidase (MAO) inhibitors

Metabolic tolerance

organ systems become more effective at eliminating the drug

Serotonergic neurons

originate along the midline of the midbrain and brainstem in the raphe nuclei

The mesostriatalpathway is important for motor control

originates in the substantia nigra of the midbrain. Parkinson's disease results from loss of these neurons.

Serotonin

participates in the control of many aspects of behavior: mood, vision, anxiety, sexual behavior, sleep, etc

Fetal alcohol syndrome results when

pregnant women abuse alcohol, with permanent damage to the fetus.

Monoamine oxidase (MAO)inhibitors

prevent the breakdown of monoamines at the synapses.

A gas neurotransmitter differs from other transmitters in three ways:

•It is produced outside axon terminals—mainly in dendrites—and diffuses out of the neuron as soon as it is produced. •No receptors are involved; it diffuses into the target cell and activates second messengers. •It can function as a retrograde transmitter by diffusing from the postsynaptic neuron back to the presynaptic neuron.

Criteria for neurotransmitter classification:

•It is synthesized in presynaptic neurons and stored in axon terminals. •It is released when action potentials reach axon terminals. •It is recognized by receptors on the postsynaptic membrane. •It causes changes in a postsynaptic cell. •Blocking its release interferes with a cell's ability to affect a postsynaptic cell.

Opiates:

•Opiumcontains morphine,an effective analgesic. •Morphine and heroin are related, and both are highly addictive. •Opiates bind to opioid receptors in the brain, especially in the periaqueductal gray.