Chapter 4
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psychopharmacology
The study of the effects of drugs on the nervous system and on behavior.
drug effect
The changes a drug produces in an organism's physiological processes and behavior.
sites of action
The locations at which molecules of drugs interact with molecules located on or in cells of the body, thus affecting some biochemical processes of these cells.
pharmacokinetics
The process by which drugs are absorbed, distributed within the body, metabolized, and excreted.
intravenous injection/IV injection
Injection of a substance directly into a vein.
intraperitoneal injection/IP injection
Injection of a substance into the peritoneal cavity--the space that surrounds the stomach, intestines, liver, and other abdominal organs.
intramuscular injection/IM injection
Injection of a substance into a muscle.
subcutaneous injection/SC injection
Injection of a substance into the space beneath the skin.
oral administration
Administration of a substance into the mouth, so that it is swallowed.
sublingual administration
Administration of a substance by placing it beneath the tongue.
intrarectal administration
Administration of a substance into the rectum.
inhalation
Administration of a vaporous substance into the lungs.
topical administration
Administration of a substance directly onto the skin or mucous membrane.
intracerebral administration
Administration of a substance directly into the brain.
intracerebroventricular administration/ICV administration
Administration of a substance into one of the cerebral ventricles.
depot binding
Binding of a drug with various tissues of the body or with proteins in the blood.
albumin
A protein found in the blood; serves to transport free fatty acids and can bind with some lipid-soluble drugs.
dose-response curve
A graph of the magnitude of an effect of a drug as a function of the amount drug administered.
therapeutic index
The ratio between the dose that produces the desired effect in 50 percent of the animals and the dose that produces toxic effects in 50 percent of the animals.
affinity
The readiness with which two molecules join together.
tolerance
A decrease in the effectiveness of a drug that is administered repeatedly.
sensitization
An increase in the effectiveness of a drug that is administered repeatedly.
withdrawal symptom/withdrawal symptoms
The appearance of symptoms opposite to those produced by a drug when the drug is administered repeatedly and then suddenly no longer taken.
placebo
An inert substance given to an organism in lieu of a physiologically active drug; used experimentally to control for the effects of mere administration of a drug.
antagonist
A drug that opposes or inhibits the effects of a particular neurotransmitter on the postsynaptic cell.
agonist
A drug that facilitates the effects of a particular neurotransmitter on the postsynaptic cell.
direct agonist
A drug that binds with and activates a receptor.
receptor blocker
A drug that binds with a receptor but does not activate it ; prevents the natural ligand from binding with the receptor.
direct antagonist
A synonym for receptor blocker.
noncompetitive binding
Binding of a drug to a site on a receptor; does not interfere with the binding site for the principal ligand.
inverse agonist
A drug that attaches to a binding site on a receptor and interferes with the action of the receptor; does not interfere with the binding site for the principal ligand.
indirect agonist
A drug that attaches to a binding site on a receptor and facilitates the action of the receptor; does not interfere with the binding site for the principal ligand.
presynaptic heteroreceptor
A receptor located in the membrane of a terminal button that receives input from another terminal button by means of an axoaxonic synapse; binds with the neurotransmitter released by the presynaptic terminal button.
acetyl-CoA
A cofactor that supplies acetate for the synthesis of acetylcholine.
choline acetyltransferase/ChAT
The enzyme that transfers the acetate ion from acetyl coenzyme A to choline, producing the neurotransmitter acetylcholine.
botulinum toxin
An acetylcholine antagonist: prevents release by terminal buttons.
black widow spider venom
A poison produced by the black widow spider that triggers the release of acetylcholine.
neostigmine
A drug that inhibits the activity of acetylcholinesterase.
hemicholinium
A drug that inhibits the uptake of choline.
nicotinic receptor
An ionotropic acetylcholine receptor that is stimulated by nicotine and blocked by curare.
muscarinic receptor
A metabotropic acetylcholine receptor that is stimulated by muscarine and blocked by atropine.
atropine
A drug that blocks muscarinic acetylcholine receptors.
curare
A drug that blocks nicotinic acetylcholine receptors.
monoamine
A class of amines that includes indolamines such as serotonin and catecholamines such as dopamine norepinephrine, and epinephrine.
catecholamine/catecholamines
A class of amines that includes the neurotransmitters dopamine, norepinephrine, and epinephrine.
dopamine/DA
A neurotransmitter; one of the catecholamines.
L-DOPA
The levorotatory form of DOPA; the precursor of the catecholamines; often used to treat Parkinson's disease because of its effect as a dopamine agonist.
nigrostriatal system
A system of neurons originating in the substantia nigra and terminating in the neostriatum (caudate nucleus and putamen).
mesolimbic system
A system of dopaminergic neurons originating in the ventral tegmental area and terminating in the nucleus accumbens, amygdala, and hippocampus.
mesocortical system
A system of dopaminergic neurons originating in the ventral tegmental area and terminating in the prefrontal cortex.
Parkinson's disease
A neurological disease characterized by tremors, rigidity of the limbs, poor balance, and difficulty in initiating movements; caused by degeneration of the nigrostriatal system.
AMPT
A drug that blocks the activity of tyrosine hydroxylase and thus interferes with the synthesis of the catecholamines.
reserpine
A drug that interferes with the storage of monoamines in synaptic vesicles.
apomorphine
A drug that blocks dopamine autoreceptors at low doses; at higher doses blocks postsynaptic receptors as well.
methylphenidate/cocaine
A drug that inhibits the reuptake of dopamine.
monoamine oxidase/MAO
A class of enzymes that destroy the monoamines: dopamine, norepinephrine, and serotonin.
deprenyl
A drug that blocks the activity of MAO-B; acts as a dopamine agonist.
chlorpromazine
A drug that reduces the symptoms of schizophrenia by blocking dopamine D2 receptors.
clozapine
A drug that reduces the symptoms of schizophrenia, apparently by blocking dopamine D4 receptors.
norepinephrine/NE
One of the catecholamines; a neurotransmitter found in the brain and in the sympathetic division of the autonomic nervous system.
epinephrine
One of the catecholamines; a hormone secreted by the adrenal medulla; serves also as a neurotransmitter in the brain.
fusaric acid
A drug that inhibits the activity of the enzyme dopamine-beta-hydroxylase and thus blocks the production of norepinephrine.
moclobemide
A drug that blocks the activity of MAO-A; acts as a noradrenergic agonist.
locus coeruleus
A dark-colored group of noradrenergic cell bodies located in the pons near the rostral end of the floor of the fourth ventricle.
axonal varicosities
Enlarged regions along the length of an axon that contain synaptic vesicles and release a neurotransmitter or neuromodulator.
serotonin/5-HT
An indolamine transmitter substance; also called 5-hydroxytryptamine.
PCPA
A drug that inhibits the activity of tryptophan hydroxylase and thus interferes with the synthesis of 5-HT.
D system
A system of serotonergic neurons that originates in the dorsal raphe nucleus; its axonal fibers are thin, with spindle-shaped varicosities that do not appear to form synapses with other neurons.
M system
A system of serotonergic neurons that originates in the median raphe nucleus; its axonal fibers are thick and rounded and appear to form conventional synapses with other neurons.
fluoxetine
A drug that inhibits the reuptake of 5-HT.
fenfluramine
A drug that stimulates the release of 5-HT.
LSD
A drug that stimulates 5-HT2A receptors.
glutamate
An amino acid; the most important excitatory transmitter substance in the brain.
NMDA receptor
A specialized ionotropic glutamate receptor that controls a calcium channel that is normally blocked by Mg2+ ions; has several other binding sites.
AMPA receptor
An ionotropic glutamate receptor that controls a sodium channel; stimulated by AMPA and blocked by CNQX.
kainate receptor
An ionotropic glutamate receptor that controls a sodium channel; stimulated by kainic acid and blocked by CNQX.
metabotropic receptor
A metabotropic glutamate receptor.
PCP
Phencyclidine; a drug that binds with the PCP binding site of the NMDA receptor and serves as an inverse agonist.
GABA
An amino acid; the most important inhibitory transmitter substance in the brain.
allylglycine
A drug that inhibits the activity of GAD and thus blocks the synthesis of GABA.
muscimol
A direct agonist for the GABA binding site on the GABAA receptor.
bicuculline
A direct antagonist for the GABA binding site on the GABAA receptor.
benzodiazepine/benzodiazepines
A category of anxiolytic drugs; an indirect agonist for the GABAA receptor.
anxiolytic
An anxiety-reducing effect.
beta-CCM
A direct agonist for the benzodiazepine binding site of the GABAA receptor.
glycine
An amino acid; an important inhibitory transmitter substance in the lower brain stem and spinal cord.
strychnine
A direct agonist for the glycine receptor.
endogenous opioid/endogenous opioids
A class of peptides secreted by the brain that act as opiates.
enkephalin
One of the endogenous opioids.
naloxone
A drug that blocks opioid receptors.
anandamide
A lipid; the endogenous ligand for receptors that bind with THC, the active ingredient of marijuana.
adenosine
A nucleoside; a combination of ribose and adenine; serves as a neuromodulator in the brain.
caffeine
A drug that blocks adenosine receptors.
nitric oxide/NO
A gas produced by cells in the nervous system; used as a means of communication between cells.
nitric oxide synthase
The enzyme responsible for the production of nitric oxide.