Ch03 Flashcards
1
Q
Neurons process and transmit information through?
A
electrical and chemical signals.
2
Q
APs reach the axon terminal:
A
the presynaptic side of a synapse
3
Q
AP cause vesicles to release ______ into the synaptic cleft
A
neurotransmitter
4
Q
Two basic kinds of neurotransmitter receptors:
A
ionotropic receptors, metabotropic receptors
5
Q
Ionotropic receptors
A
quickly change shape and open or close an ion channel when the transmitter molecule binds
6
Q
Metabotropic receptors
A
alter chemical reactions in the cell.
7
Q
Criteria for neurotransmitter classification:
A
- It is synthesized in presynaptic neurons and stored in axon terminals
- it is released when APs 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.
8
Q
Amino acid neurotransmitters
A
GABA, glutamate, glycine
9
Q
Amine neurotransmitters
A
acetycholine, dopamine, norepinephrine, serotonin
10
Q
Peptide neurotransmitters
A
(neuropeptides) 200 peptides e.g., opioid peptides, oxytocin, vasopressin
11
Q
Lipid based neurotransmitters
A
endocannabinoids
12
Q
gas neurotransmitters
A
nitric oxide, carbon monoxide.
13
Q
The most common transmitters in the brain are?
A
amino acids.
14
Q
What is the most widespread excitatory transmitter
A
glutamate
15
Q
What is the most widespread inhibitory transmitter?
A
Gamma aminobutyric acid (GABA)
16
Q
What does acetylcholine do?
A
plays a major role in transmission in the forebrain
17
Q
Many cholinergic neurons are found in the
A
basal forebrain
18
Q
Loss of cholinergic neurons causes what disease?
A
Alzheimer’s disease
19
Q
What are some characteristics of alzheimer’s disease?
A
- characteristic plaques (beta amyloid) and neurofibrillary tables in AD cortex
- loss of cholinergic neurons in AD basal forebrain
20
Q
What neurotransmitter is important for many aspects of behavior?
A
dopamine
21
Q
the mesostriatal pathway is important for?
A
motor control.
mesostriatal=
meso= middle
striatal= relating to the corpus striatum
22
Q
Where do the mesostrial pathways originate from?
A
substantia nigra of the midbrian.
23
Q
What neurons are lost when parkinson’s disease is developed?
A
dopamine in the substantia nigra.
24
Q
What is the mesolimbocortical pathway important for?
A
learning shaped by positive reinforcement, addiction
25
Bradykinesia is what?
slowed movement
26
What does norepinephrine important for?
the control of many behaviors ranging from alertness, responses to stressors, to mood and to sexual behavior.
27
Noradrenergic neurons are found in the?
locus coeruleus and the lateral tegmental area.
locus= place coeruleus= dark blue
28
Serotonin participates in the control of?
behavior, anxiety, modd, sexual behavior, sleep, etc.
29
Serotonergic neurons originate along?
the midline of the midbrain and brainstem in the raphe nuclei
30
Opioid peptides are the
endogenous neurotransmitters involved in analgesia and stress responses; their effects are mimicked by opiate drugs such as morphine, that reduce the perception of pain
31
A gas neurotransmitter such as NO is different from other transmitters in these ways:
- It is produced outside axon terminals, mainly in dendrites, and diffuses out of the neuron as soon as it is produced.
- It can function as a retrograde transmitter by diffusing from the postsynaptic neuron back to the presynaptic neuron
- No receptors are involved; it diffuses into the target cell and activates second messengers.
32
What do drugs do to transmitter production?
drugs may block synthesis enzymes, axonal transport of raw materials, or the ability to store transmitter
33
What do drugs do to transmitter release?
drugs can block APs by blocking ion channels.
34
What do drugs do to transmitter clearance?
a drug may block reuptake of transmitter or block enzymes that degrade transmitter
35
What is a ligand?
any substance that binds to a receptor.
36
When a drug activates the receptor it is acting as an ____
agonist.
37
When a rug binds a receptor without activating it and also block it, it an?
antagonist
38
What does bioavailable mean?
the drug is free to act on the target- varies with route of administration
39
Biotransmormation produces?
active metabolites that may produce side effects.
40
Blood brain barrier
tight junctions between the cells of blood vessels in the CNS prevent the movement of large molecules; can limit drug availability.
41
pharmacokinetics
refers to all the factors that affect the movement of drugs from their entry into the body to their exit from the body.
42
What is binding affinity?
the degree of chemical attraction between a ligand and a receptor.
43
What is efficacy (intrinsic activity)?
the ability of a bound ligand to activate the receptor
44
What is clearance?
elimination or metabolism
45
What is a dose response curve? (DRC)
graph of the relationship between drug doses and their effects.
46
Repeated drug treatments may results in?
Drug tolerance (reduced efficacy of the drug)
47
Metabolic tolerance
organ systems become more effective at eliminating the drug
48
Functional tolerance
target tissue may alter its sensitivity to the drug by changing the number of receptors
49
down regulation
in response to an agonist- fewer receptors
50
up regulation
in response to an antagonist more receptors
51
cross tolerance
tolerance to one drug is generalized to other drugs in its class
52
Psychoactive drugs can?
relieve severe psychiatric symptoms (e.g. hallucinations and delusions in schizophrenia)
53
First generation antipsychotics (neuroleptics) are?
A class of drugs that alleviate symptoms of schizophrenia, typically by blocking dopamine D2 receptors.
54
Second generation antipsychotics
act on receptors in addition to or other than D2 receptors and may relieve symptoms resistant to typical antipsychotics
55
Antidepressant drugs are used to treat disturbances of mood called?
Affective disorders.
56
Monoamine oxidase (MAO) inhibitors prevent?
- the breakdown of monoamines at the synapses
- accumulation of transmitters, prolonging their activity, is a major feature of antidepressants.
57
Tricyclic antidepressants block what?
reuptake of serotonin and norepinephrine
58
Selective serotonin reuptake inhibitors (SSRIs) do what?
Act specifically at serotonergic synapses
ex) prozac or celexa
59
Depressants are drugs that?
reduce nervous system activity
60
Barbiturates, early anxiolytics, and sleep aids do what?
depress nervous activity. Addictive and easy to overdose on.
61
Specific anxiolytics such as benzodiazepines act as?
Agonists on GABAz receptors and enhance the inhibitory effects of GABA.
62
Opium contains?
morphine, an effective analgesic.
63
Morphine and heroin are related and both are?
highly addictive
64
Opiates bind to?
opioid receptors in the brain, especially in the periaqueductal gray.
65
Endogenous opioids like...
enkephalins, endorphins, and dynorphins are peptides produced in the brain.
66
What are the three kinds of opioid receptors?
delta, kappa, and mu.
They are all metabotropic receptors.
67
How do you reverse the effects of opiates?
With drugs that block opioid receptors (Naloxone, naltrexone)
68
Cannabis/weed: smoking, vaping, edibles. The active ingredient is?
delta-9-tetrahydrocannabinol (THC)
69
The brain contains specific cannabinoid receptors that?
mediate the effects of compounds like THC.
70
What do stimulants do?
Increase nervous system activity by increasing excitatory input or decreasing inhibitory activity.
71
Caffeine is an agonist on?
adenosine receptors. Involved in the regulation of sleep.
72
Adenosine increases towards?
The end of the day or with sleep deprivation and acts to decrease the activity of the brain regions involved in maintaining wakefulness
73
What does caffeine do to adenosine?
blocks it. increases the release of dopamine and acetycholine.
74
Withdrawal symptoms of caffeine include?
headaches, fatigue, anxiety, shakiness, and craving.
75
Nicotine, from tobacco, acts as a?
Stimulant.
76
Nicotine acts as an agonist or antagonist?
agonist
77
How does cocaine work?
It acts by blocking reuptake of monoamine transmitters (dopamine) so that they accumulate in synapses throughout the brain, boosting their effects.
78
Chronic use of cocaine leads to?
Deficits in executive functions that involve the pre frontal cortex.
79
Amphetamines are a group of?
synthetic drugs that produce euphoria and increase confidence and concentration.
80
Amphetamine causes a?
Larger than normal release of transmitter (dopamine, norepinephrine) at axon terminals.
81
What do depressants do to the nervous system?
They reduce the nervous system activity.
82
Alcohol's effects are
biphasic- an initial stimulant phase, followed by a depressant (inhibited neural activity) phase- effects on GABA receptors.
83
Alcohol acts on which receptors?
GABA receptors and dopamine mediated reward systems.
84
Korsakoff's syndrome
Difficulty remembering recent events and new information. Confabulation= inaccurate memories filled in with fabricated experiences.
85
Delirium tremens
Agitation, aggression, or irritability. Confusion.
86
Fetal alcohol syndrome
results when pregnant women abuse alcohol, with permanent damage to the fetus.
87
What do opiates mimic?
endogenous opioids (natural pain killers)
88
What are some examples of opiates?
Morphine, heroin, fentanyl, oxycontin, buprenorphin
89
behavioral management for heroin addiction has a ____ success rate.
10 to 30 percent.
90
Hallucinogens (psychedelic drugs) alter what?
sensory perception and produce unusual experiences through diverse neural actions.
91
LSD activates which receptors?
serotonin 5-HT2a receptors in the visual cortex
92
What does MDMA (ecstasy) do?
- releases dopamine and serotonin
- hallucinatory
93
Ketamine is an antagonist for what receptor?
NMDA
94
Substance use disorders (addiction) are defined as?
chronic, relapsing brain diseases.
95
What are the 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 behavior controlled by positive rewards)
96
Many addictive drugs cause dopamine release in the?
Nucleus accumbens.
97
What is reward?
the positive effect an object or condition (drug, food, sex, etc.) has on the user.
98
What is usually considered the major reward system?
mesolimbocortical dopamine system
99
Virtually all abused drugs increase dopamine in the?
Ventral tegmental area (VTA)
100
Addiction and withdrawal are independent or dependent?
independent; they even occur in different parts of the brain.
101
Agnostic treatments _____ the drug's effects
mimic
102
Antagonistic treatments _____ drug effects
block
103
aversive treatments cause an?
unpleasant reaction when the addict uses the drug.
104
What do anti drug vaccines do?
stimulate the immune system to make antibodies that degrade the drug.
105
Genes that contribute to addiction generally are...
- involved with neurotransmitter systems
- affect how the individual responds to the drug.
