Final Ch4 Neurochemistry

question

Neurochemistry
answer

focuses on the basic chemical composition and processes of the nervous system
question

Neuropharmacology
answer

is the study of compounds that selectively affect the nervous system.
question

Six criteria for neurotransmitters
answer

1) Exist in presynaptic axon terminals 2) Synthesized in presynaptic cells 3) Released during action potentials 4) Receptors for it exist on PSM. 5) Produces changes in postsynaptic potentials. 6) When blocked, prevents changes.
question

Amines
answer

quaternary amines (acetylcholine) mono amines
question

quaternary amines
answer

(acetylcholine)
question

mono amines
answer

*catecholemines* (norepinephrine, epinephrine, dopamine) *indoleamines* (serotonin, melatonin)
question

Amino acids
answer

(GABA, glutamate)
question

Peptide neurotransmitters
answer

(opioids)
question

Neurotransmitters affect targets by acting on
answer

receptors
question

receptors
answer

protein molecules in the postsynaptic membrane.
question

Ionotropic receptors
answer

are fast-open an ion channel when the transmitter molecule binds
question

Metabotropic receptors
answer

are slow-when activated they alter chemical reactions in the cell, such as a G protein system, to open an ion channel.
question

ligand
answer

is a substance that binds to a receptor
question

A ligand has one of three effects:
answer

agonist antagonist inverse agonist
question

agonist
answer

initiates the normal effects of the receptor.
question

antagonist
answer

blocks the receptor from being activated by other ligands.
question

inverse agonist
answer

initiates an effect that is the opposite of the normal function.
question

Endogenous
answer

from inside
question

Exogenous
answer

from outside
question

4 biogenic amine production sites
answer

Ralphe Nuclie – seratonin Basal Ganglia – dopamine Basal Forebrain – acetocholine Locus Corealeus – epinephrine
question

Acetylcholine
answer

-plays a role in cognition, muscle contractions and the parasympathetic response -Nicotinic and Muscarinic receptors -Produced in midbrain and basal forebrain
question

Dopamine (DA)
answer

-This pathway is important in motor control and pleasure. -This pathway is implemented in to schizophrenia and movement disorders -is found in neurons in: midbrain and basal ganglia
question

Norepinephrine (NE)
answer

-NE is also known as noradrenaline-cells producing it are noradrenergic. Sympathetic response -is released in the Locus coeruleus (pons) and midbrain
question

The CNS has four subtypes of NE receptors-which are all…
answer

metabatropic
question

Serotonin (5HT)
answer

– is implicated in sleep, mood, sexual behavior, and anxiety. -Antidepressants such as Prozac increase 5HT activity, with effects depending on which receptor subtype is affected. -cell bodies are mainly found in the raphe nuclei and its serotonergic fibers project widely.
question

Amino acid transmitters:
answer

Glutamate GABA
question

Glutamate
answer

is the major excitatory neurotranmitter of the CNS
question

GABA
answer

is the major inhibitory neurotranmitter of the CNS
question

Excitotoxicity
answer

neural injury such as stroke may cause excess release of glutamate, which is toxic to neurons
question

Endorphins
answer

-are endogenous opioid peptides -They are produced in the pituitary and hypothalamus during exercise, pain, spicy food consumption and sex
question

binding affinity
answer

is the degree of chemical attraction between a ligand and a receptor.
question

efficacy (or intrinsic activity)
answer

is the ability of a bound ligand to activate the receptor.
question

Agonists
answer

high efficacy
question

Antagonists
answer

have low efficacy
question

Partial agonists or antagonists
answer

produce a medium response regardless of dose.
question

Competitive ligands
answer

are drugs that bind to the same receptor site as the neurotransmitter.
question

noncompetitive ligand
answer

binds instead to a modulatory site on the receptor. -The modulatory site, when bound by a compound, alters the receptor’s response.
question

What is a dose-response curve (DRC) ?
answer

is a graph of the relationship between drug doses and the effects. -The DRC is a tool to understand pharmacodynamics-the functional relationship between drugs and their targets.
question

Drug tolerance can develop after
answer

successive treatments have decreasing effects
question

Metabolic tolerance organ systems become…
answer

more effective at eliminating the drug (e.g. alcohol)
question

Functional tolerance
answer

target tissue may show altered sensitivity to the drug (ecstacy)
question

Changes in numbers of receptors can alter sensitivity in the direction …
answer

opposite to the drug’s effects:
question

Neurons down-regulate in response to an agonist drug meaning…
answer

fewer receptors available
question

Neurons up-regulate in response to
answer

an antagonist.
question

Cross-tolerance
answer

is tolerance to a whole class of chemically similar drugs.
question

Withdrawal symptoms
answer

may be caused by drug tolerance.
question

Sensitization
answer

occurs when drug effects become stronger with repeated treatment.
question

bioavailable
answer

free to act on the target-varies with route of ingestion. -Duration of a drug’s effect is determined by how it is metabolized.
question

Biotransformation produces active metabolites
answer

that may produce side effects.
question

Neuromodulators
answer

affect either transmitter release or receptor response.
question

Caffeine is an…
answer

exogenous neuromodulator that blocks the effect of adenosine, an endogenous neuromodulator that normally inhibits catecholamine release.
question

transporters
answer

specialized proteins that return the transmitter to the presynaptic membrane.
question

Some drugs affect how long transmitters remain in the synapse, they interfere with…
answer

transporters
question

When drugs affect the breakdown of neurotransmitters they are affecting the
answer

degradation of the drug
question

Cholinesterase inhibitors inhibit the breakdown of what drug
answer

ACh (acetycholine)
question

Antipsychotic (neuroleptic) drugs
answer

a class of drugs to treat schizophrenia
question

Typical neuroleptics
answer

are selective dopamine D2 antagonists.
question

Atypical neuroleptics
answer

block serotonin receptors and may reduce negative symptoms of schizophrenia.
question

Antipsychotic (neuroleptic) drugs, Typical neuroleptics, and Atypical neuroleptics all seem to do what to patients
answer

-reduce motor activity, which helps alleviate major agitation in some patients -They can also give rise to tardive dyskinesia (reversible)
question

Too much dopamine is associated with
answer

psychosis
question

Too little dopamine is associated with
answer

movement disorders
question

Antidepressants
answer

treat depression.
question

Monoamine oxidase (MAO)
answer

inhibitors prevent the breakdown of monoamines at the synapses.
question

Tricyclic antidepressants
answer

increase norepinephrine and serotonin at the synapses by blocking their reuptake into presynaptic axon terminals.
question

Selective serotonin reuptake inhibitors (SSRIs)
answer

– allow serotonin to accumulate in the synapses, with fewer side effects than tricyclics. -like Prozac or Zoloft
question

Anxiolytics, or tranquilizers
answer

reduce nervous system activity.
question

Benzodiazepine agonists act on what?
answer

also known as minor tranquilizers, and act on GABAA receptors
question

GABA receptors have several binding sites, that enhance or inhibit what??
answer

GABA’s effects
question

Benzodiazepines bind at an
answer

orphan receptor-no known endogenous ligand
question

Allopregnanolone
answer

a steroid, is elevated during stress and is calming
question

Alcohol’s effects are biphasic which means…
answer

an initial stimulant phase followed by a depressant phase
question

Alcohol activates GABAA receptors which increase
answer

social disinhibition, lethergy and loss of motor coordination for 4 hours
question

Alcohol also stimulates dopamine pathways, causing …
answer

euphoric effects which last for six hours
question

Alcohol abuse damages nerve cells, especially in the …
answer

frontal lobe, yet some damage is reversible.
question

analgesic
answer

pain killer
question

Opium contains
answer

morphine, an effective analgesic, or painkiller
question

Morphine and heroin are …
answer

related
question

morphine and heroin bind to what kind of receptors?
answer

opiates bind to opioid receptors in the brain, especially in the locus coeruleus and the periaqueductal gray.
question

Endogenous opiates
answer

peptides produced in the body that bind to opioid receptors and relieve pain-are also addictive.
question

The brain contains orphan cannabinoid receptors to mediate the effects of
answer

THC and other compounds
question

Endocannabinoids
answer

homologs of marijuana produced in the brain-act as retrograde messengers and may influence neurotransmitter release from the presynaptic neuron.
question

Anandamide
answer

-an endocannabinoid Altered memory formation
question

Anadamide affects include
answer

-Altered memory formation -Appetite stimulation -Reduced pain sensitivity -Protection from excitotoxic brain damage
question

Nicotine from tobacco
answer

-Increases heart rate, blood pressure, hydrochloric acid secretion, and bowel activity -Acts as an agonist on nicotinic ACh receptors in the ventral tegmental area
question

Cocaine, the purified extract, can be used as a
answer

anesthetic
question

cocaine increases
answer

catecholamine stimulation and is highly addictive
question

Dual dependence
answer

is addiction to the effects of the interaction of two drugs.
question

Cocaine blocks which transporters
answer

monoamine transporters-especially dopamine-slows reuptake of neurotransmitters, enhancing their effects.
question

Amphetamine and methamphetamine are what kind of stimulants…
answer

synthetic stimulants that resemble catecholamines in structure. -They cause the release of neurotransmitters even in the absence of action potentials
question

Short-term effects of amphetamines include…
answer

alertness, euphoria, and stamina.
question

Long-term use leads of amphetamines include…
answer

sleeplessness weight loss, and schizophrenic symptoms
question

Hallucinogens
answer

sensory perception and produce peculiar experiences.
question

Phencyclidine (PCP) ) or angel dust,
answer

produces feelings of depersonalization and detachment from reality -Its many side effects include combativeness and catatonia. -PCP has been proposed as a chemical model for schizophrenia.
question

LSD
answer

(acid), mescaline (peyote), and psilocybin (magic mushrooms) have mainly visual effects.
question

what kind of receptor is pcp
answer

NMDA receptor antagonist and stimulates DA release
question

Ketamine (Special K)
answer

is a less potent NMDA antagonist that works in the prefrontal cortex.
question

Ketamine Like PCP
answer

can produce transient psychotic symptoms, at high doses
question

MDMA (Ecstasy) is a
answer

hallucinogenic amphetamine derivative-its major actions are increases in serotonin levels and changes in dopamine and prolactin levels. -Chronic ecstasy use produces persistent effects and damage to serotonin-producing neurons
question

The Moral Model
answer

blames the abuser for a lack of moral character or a lack of self-control
question

The Disease Model
answer

the abuser requires medical treatment; however, an abnormal condition in abusers has not been identified
question

The Physical Dependence Model
answer

called the withdrawal avoidance model, says abusers use drugs to avoid withdrawal symptoms
question

The Positive Reward Model
answer

drug use is a behavior controlled by positive rewards, with no disease
question

Many addictive drugs cause dopamine release in the what part of the brain
answer

nucleus accumbens -Some axons that terminate here originate in the ventral tegmental area (VTA) and are involved in the reward pathway. -The addictive power of drugs may come from stimulating this pathway.
question

People with damage to the insula pathway, a brain region within the frontal cortex.
answer

area have been able to stop smoking effortlessly.
question

Cue-induced drug use
answer

is the increased likelihood of using a drug because factors are present that were also present when the drug was last used.
question

Factors in susceptibility to addiction
answer

-biological-sex, genetic predisposition -Family situation-family breakup, poor relationships, sibling drug users -Personal characteristics-aggressiveness, emotional control -Environmental factors-peer pressure, social factors
question

Medications to treat drug abuse Drugs for detoxification:
answer

benzodiazepines and drugs to help ease withdrawal symptoms
question

Antagonists to the addictive drug
answer

block effects of the abused drug but may produce withdrawal symptoms
question

Agonists or analogs of the addictive drug
answer

-partially activate the same pathways, such as methadone or nicotine patches
question

Reward-blocking medications
answer

block positive reward effects of the abused drug but may produce a lack of all pleasurable feelings
question

Medications that alter drug metabolism-
answer

like *Antabuse*, which makes drinking produce unpleasant side effects
question

Anticraving medications
answer

reduce the appetite for the abused substance
question

immunization
answer

prompts the immune system to remove targeted drugs

Get instant access to
all materials

Become a Member