Chapter 4: Psychopharmacology Flashcards
Psychopharmacology
The study of the effects of drugs on the nervous system and behavior
Drug
An exogenous chemical not necessary for normal cellular functioning that significantly alters the functions of certain cells of the body when taken in relatively low doses
Two major aspects of drug influence:
Drug effects and sites of action
Drug effect
the changes we can observe in an individual’s physiological processes and behavior
Sites of action
the points at which molecules of drugs interact with molecules located on or in cells of the body, thus affecting some biochemical processes of these cells
Psychopharmacologists study drugs that affect the nervous system and behavior in two broad classes: ________ drugs and drugs of _____
therapeutic; abuse
Pharmacokinetics is ___.
the life cycle of a drug molecule.
Steps of pharmacokinetics:
1.) Absorption
2.) Distribution within the body
3.) Metabolized
4.) Excretion
Drug is administered and absorbed through tissues
Absorption
Drug is distributed throughout the body and blood
Distribution
Drug is changed to an inactive form by enzymes (usually in liver)
Metabolism
Drug is excreted in urine by kidneys
Excretion
Routes of drug administration (absorption):
Intravenous injection, intraperitoneal injection, intramuscular injection, subcutaneous injection,
intracerebral administration, intracerebroventricular (ICV) administration, oral administration, sublingual administration, inhalation, topical administration
The fastest route of administration is ________ injection
intravenous
Routes of administration used if the drug can’t cross the blood-brain barrier
Intracerebral administration and ICV administration
The most common route of administration is ________ ______
oral administration
Insufflation, or “snorting,” is considered _______ administration
topical
True or false: Drugs exert effects only at their sites of action
True
Most sites of action are located on or in cells of the CNS/PNS.
CNS
The most important factor in determining the rate of distribution is ____ _______ because ________
lipid solubility; fat molecules can cruise on through the BBB
True or false: Not all drugs are excreted
False, all drugs are eventually excreted, mostly by the kidneys
Many drugs are metabolized and deactivated by _______ in the brain and liver
enzymes
During metabolism, sometimes enzymes transform molecules into ________ versions.
more active
The dose-response curve locates the point of _________ _____.
maximum effect
True or false: most drugs have more than one effect
True
The _________ _____ measures a drug’s margin of safety
Therapeutic index
Why are some drugs more effective than others?
Sites of action; affinity of a drug with its site of action
Affinity
The readiness with which the two molecules join together
The most desirable drug has high/low affinity for sites of action producing therapeutic effects and high/low affinity for sites of action producing toxic side effects
high; low
Often, when a drug is administered repeatedly, its effects _______, which is called tolerance.
diminish
Sometimes a drug becomes more and more effective after repeated administration, called _________.
Sensitization
After someone has built up tolerance to a certain drug and they suddenly stop taking it, they may experience __________ symptoms
withdrawal
Withdrawal symptoms indicates _______ _______.
Physical dependence
Compensatory mechanisms the brain uses in response to repeated use of a drug:
Decrease the effectiveness of binding with receptors; coupling process
An inactive substance that may have physiological or psychological effects
Placebo
The effects of a placebo results from changes in _______, _______, or _______.
motivation, expectation, learning
True or false: Placebo studies for new drugs are required by the FDA
True
______ drugs facilitate postsynaptic effects
Agonist
_________ drugs block or inhibit postsynaptic effects
Antagonists
Most drugs affecting behavior affect ______ _______
Synaptic transmission
A drug that mimics the effects of a neurotransmitter acts as a ______ ______
direct agonist
How do direct agonists work?
Direct agonists attach to the binding site to which the neurotransmitter normally attaches, causing the receptor to respond in the same way as when the neurotransmitter is present.
Some drugs act as antagonists by __________________
preventing release of NTs from the terminal button
Other drugs act as agonists by ______________________
binding with proteins and triggering release of NTs
An analogy for the direct agonist is the right/wrong key in the keyhole
right
An analogy for the receptor blocker (direct antagonist) is the right/wrong key in keyhole
wrong
How do receptor blockers (direct antagonists) work?
Binds with postsynaptic receptors but does not open the ion channel or trigger intracellular events
Another word for a direct antagonist is ________ _____
receptor blocker
Noncompetitive binding occurs when postsynaptic receptor sites have _____ binding site
more than one
In ___________ _______, molecules of the neurotransmitter bind with one site, and other substances bind with the others
noncompetitive binding
Examples of an indirect antagonist:
PCP, ketamine
Examples of an indirect agonist
Valium
Which two processes result in the termination of the postsynaptic potential?
Reuptake; deactivation via enzyme
If reuptake is blocked, would it have an agonist or antagonist effect?
Agonist, causing the neighboring neuron to be more likely to fire
If a deactivating enzyme is blocked, would it have an agonist or antagonist effect?
Agonist
Unlike neurotransmitters, __________ adjust the release rather than directly shooting them off.
neuromodulaters
Function of NT Glutamate:
Excitatory; interacts with other neurotransmitter systems
Which two NTs do the most work in the brain?
Glutamate (excitatory); GABA (inhibit)
Function of NT GABA:
Inhibitory; interacts with other neurotransmitter systems
Function of NT Dopamine:
Voluntary movement, attention, learning, reinforcement, planning, problem solving
Function of NT Norephinephrine/epinephrine
Vigilance
Function of NT Serotonin:
Mood regulation, eating, sleep, dreaming, arousal, impulse control
CNS Function of NT Histamine:
Wakefulness
PNS function of NT Histamine:
Immune response
PNS function of NT Serotonin:
Enteric nervous system (digestive)
PNS function of NTs Norepinephrine/Epinephrine
Autonomic nervous system regulation
CNS function of Opioids:
Reinforcement, pain modulation
PNS function of Opioids:
Pain modulation
CNS function of Endocannabinoids:
Appetite regulation
PNS function of Endocannabinoids:
Immune response
Two amino acid NTs in the brain:
Glutamate and GABA
Amino acid NT in the spinal cord and lower brain stem:
Glycine (inhibitory)
The main excitatory neurotransmitter in the brain and spinal cord is _______
Glutamate
Four major types of receptor sites of glutamate:
NMDA receptor, AMPA receptor, kainate receptor, metabotropic glutamate receptor
____ blocks the glutamate binding site
AP5
The inhibitory neurotransmitter with widespread distribution in brain and spinal cord.
GABA
GABA-secreting neurons exhibit inhibitory influence to help keep brain ______
stable
_______ may be the result of lacking or poorly functioning GABA-secreting neurons or receptors
Seizures (too much going on at once!)
GABA(a) receptors are ionotropic/metabotropic and control _____ channels.
ionotropic; chloride
ACh functions in CNS/PNS.
Both…trick question, girl. ; )
In the PNS, ACh is the primary neurotransmitter to control _______ ________.
muscle contraction
In the CNS, ACh is located mostly in the _________ and is important for _______ and ______.
brain stem; REM sleep; learning
The ionotropic ACh receptor is stimulated by _______.
Nicotine
The metabotropic ACh receptor is stimulated by _________.
muscarine
ACh is deactivated by the enzyme ________, present in the postsynaptic membrane
AChE
AChE inhibitors are used to treat ___________ _______. How?
myasthenia gravis; By inhibiting the inhibitor. What power.
Monoamine neurotransmitters:
Dopamine, norepinephrine, epinephrine, serotonin (because they have more of a modulating effect)
________ modulate functions of widespread regions of the brain, either increasing or decreasing brain functions.
Monoamines
True or False: Dopamine is inhibitory.
False; DA produces both excitatory and inhibitory postsynaptic potentials, depending on the postsynaptic receptor
Dopamine affects _______, _______, _______, and reinforcing effects of ______.
movement, attention, learning, drugs
The three most important DA pathways originate in the ________.
Midbrain
Three most important DA pathways:
1.) Nigrostriatal system
2.) Mesolimbic system
3.) Mesocortical system
The Nigrostriatal system helps with ________.
Movement
The mesolimbic system helps with ________.
reward
The mesocortical system helps with ________ and ________.
memory; planning
Degeneration of dopaminergic neurons that connect the substantia nigra with the caudate nucleus causes ______________.
Parkinson’s disease
List the catecholamines:
Dopamine
Norepinephrine
Epinephrine
List the indolamines:
Serotonin
List the ethylamines:
Histamine
Origin and location of terminal buttons of the nigrostriatal system:
Substantia nigra –> neostriatum (caudate nucleus and putamen)
Origin and location of terminal buttons of the mesolimbic system:
Ventral tegmental area –> Nucleus accumbens, amygdala, hippocampus
Origin and location of terminal buttons of the mesocortical system:
Ventral tegmental area –> prefrontal cortex
Synthesis of the catecholamines:
1.) Tyrosine
*tyrosine hydroxylase
2.) L-DOPA
*DOPA decarboxylase
3.) Dopamine
*Dopamine Beta-hydroxylase
4.) Norepinephrine
People with Parkinson’s disease are often given the drug ______, which can cross the BBB for conversion to dopamine
L-DOPA
The dopamine receptors are ionotropic/metabotropic
metabotropic
___________ ___________ remove dopamine from the synapse
Dopamine transporters
Deactivation of catecholamines is regulated by an enzyme called ______.
MAO
Norepinephrine is found in the CNS/PNS.
Both. Burn. 🔥
Norepinephrine is made when vesicles fill with ___, then an enzyme converts to NE.
DA
NE is released through _______ ________.
Axonal varicosities
NE receptors are ionotropic; metabotropic
metabotropic
The _________ ________ removes excess norepinephrine from the synapse
Norepinephrine transporter
_______ deactivates excess norepinephrine in the terminal buttons
MAO-A
Serotonin is found in __ clusters, most located in the raphe nuclei of the midbrain, pons, and medulla
9
The precursor for 5-HT (serotonin) is ______.
tryptophan
Serotonin plays a role in regulation of _____, control of ______, ______, _______, ___ regulation, and _______.
mood, eating, sleep, arousal, pain, dreaming
The ________ _______ removes 5-HT from the synapse
Serotonin transporter
Drugs that inhibit the uptake of serotonin:
Fluoxetine (Prozac–depression, some anxiety, OCD)
MDMA (Ecstasy…hallucinating much?)
Histamine pathways are found only in the ________.
hypothalamus
Drugs that block histamines cause drowsiness, acting as agonists/antagonists.
antagonists
Two or more amino acids linked by peptide bonds
Peptides
True or false: peptides are released from all parts of the terminal button
True
The best known peptides are ___________ _______, and their receptors are called enkephalins.
endogenous opioids
The natural ligands for peptide receptors are called _________.
enkephalins
Naloxone is used clinically to reverse ______.
overdose
_____ neurotransmitters appear to be synthesized on demand, produced, or released as needed rather than stored in synaptic vesicles.
Lipid
The best known lipid neurotransmitters are ____________, responsible for the effects of THC in marijuana
endocannabinoids
