chapter 4: chemistry of behavior

Question 1

Exogenous

Answer 1

Arising from outside the body

Question 2

Endogenous

Answer 2

Produced inside the body

Question 3

Presynaptic

Answer 3

Located on the “transmitting” side of a synapse

Question 4

Synapse

Answer 4

The location at which information flows between a presynaptic neuron and a postsynaptic neuron, often through the conversion of electrical activity in the presynaptic neuron into a secretion of chemical neurotransmitter that alters the functioning of the postsynaptic neuron

Question 5

Exocytosis

Answer 5

A cellular process that results in the release of a substance into the extracellular space

Question 6

Neurotransmitter

Answer 6

A signaling chemical, released by a presynaptic neuron, that diffuses across the synaptic cleft to alter the functioning of the postsynaptic neuron

Question 7

Neurotransmitter receptor

Answer 7

A specialized protein that is embedded in the cell membrane, allowing it to selectively sense and react to molecules of the corresponding neurotransmitter

Question 8

Postsynaptic

Answer 8

Located on the “receiving” side of a synapse

Question 9

Reuptake

Answer 9

The reabsorption of molecules of neurotransmitter by the neurons that released them, thereby ending the signaling activity of the transmitter molecules

Question 10

Transporter

Answer 10

A specialized membrane component that returns transmitter molecules to the presynaptic neuron for reuse

Question 11

Ionotropic receptor

Answer 11

A receptor protein containing an ion channel that opens when the receptor is bound by an an agonist

Also called ligand-gated ion channel

Question 12

Metabotropic receptor

Answer 12

A receptor protein that does not contain ion channels but may, when activated, use a G protein system to open nearby ion channels or to produce other cellular effects

Question 13

Amine neurotransmitter

Answer 13

A neurotransmitter based on modifications of a single amino acid nucleus. Examples include acetylcholine, serotonin, and dopamine

Question 14

Amino acid neurotransmitter

Answer 14

A neurotransmitter that is itself an amino acid. Examples include GABA, glycine, and glutamate

Question 15

Peptide neurotransmitter

Answer 15

A neurotransmitter consisting of a short chain of amino acids

Also called neuropeptide

Question 16

Gas neurotransmitter

Answer 16

A neurotransmitter that is a soluble gas. Examples include nitric oxide and carbon monoxide

Question 17

Acetylcholine (ACh)

Answer 17

A neurotransmitter found in the autonomic nervous system, motor systems, and throughout the brain

Question 18

Cholinergic

Answer 18

Referring to cells that use acetylcholine as their synaptic transmitter

Question 19

Basal forebrain

Answer 19

A region, ventral to the basal ganglia, that is the major source of acetylcholine in the brain

Question 20

Dopamine (DA)

Answer 20

A monoamine transmitter found in the midbrain –especially the substantial nigra – and in the basal forebrain

Question 21

Dopaminergic

Answer 21

Referring to cells that use dopamine as their synaptic transmitter

Question 22

Substantia nigra

Answer 22

A brainstem structure that innervates the basal ganglia and is the source of all dopaminergic projections

Question 23

Ventral tegmental area (VTA)

Answer 23

A portion of the midbrain that projects dopaminergic fibers to the nucleus accumbens

Question 24

Serotonergic

Answer 24

Referring to cells that use serotonin as their synaptic transmitter

Question 25

Raphe nuclei

Answer 25

A string of nuclei in the midline of the midbrain and brainstem that contain most of the serotonergic neurons of the brain

Question 26

Serotonin (5-HT)

Answer 26

A synaptic transmitter that is produced in the raphe nuclei and is active in structures throughout the cerebral hemispheres

Question 27

Noradrenergic

Answer 27

Referring to cells using norepinephrine (noradrenaline) as a transmitter

Question 28

Norepinephrine (NE)

Answer 28

A neurotransmitter that is produced and released by sympathetic postganglionic neurons to accelerate organ activity. It is also produced in the brainstem and found in projections throughout the brain Also called noradrenaline

Question 29

Locus coeruleus

Answer 29

A small nucleus in the brainstem whose neurons produce norepinephrine and modulate large areas of the forebrain

Question 30

Lateral tegmental area

Answer 30

A brainstem region that provide some of the norepinephrine-containing projections of the brain

Question 31

Glutamate

Answer 31

An amino acid transmitter, the most common excitatory transmitter

Question 32

Gamma-aminobutyric acid (GABA)

Answer 32

A widely distributed amino acid transmitter, and the main inhibitory transmitter in the mammalian nervous system

Question 33

Opioid peptides

Answer 33

A type of endogenous peptide that mimics the effects of morphine in binding to opioid receptors and producing marked analgesia and reward

Question 34

Retrograde transmitter

Answer 34

A neurotransmitter that diffuses from the postsynaptic neuron back to the presynaptic neuron

Question 35

Ligand

Answer 35

A substance that binds to receptor molecules, such as a neurotransmitter or drug that binds postsynaptic receptors

Question 36

Agonist

Answer 36

A molecule, usually a drug, that binds a receptor molecule and initiates a response like that of another molecule, usually a neurotransmitter

Question 37

Antagonist

Answer 37

A molecule, usually a drug, that interferes with or prevents the action of a neurotransmitter

Question 38

Binding affinity

Answer 38

The propensity of molecules of a drug (or other ligand) to bind to receptors Also called affinity

Question 39

Efficacy or intrinsic activity

Answer 39

The extent to which a drug activates a response when it binds to a receptor

Question 40

Dose-response curve (DRC)

Answer 40

A formal graph of a drug's effects (on the y-axis) versus the dose given (on the x-axis)

Question 41

Bioavailable

Answer 41

Referring to a substance, usually a drug, that is present in the body in a form that is able to interact with physiological mechanisms

Question 42

Biotransformation

Answer 42

The process in which enzymes convert a drug into a metabolite that is itself active, possibly in ways that are substantially different from the actions of the original substance

Question 43

Blood-brain barrier

Answer 43

The mechanisms that make the movement of substances from blood vessels into brain cells more difficult than exchanges in other body organs, thus affording the brain greater protection from exposure to some substances found in the blood

Question 44

Drug tolerance

Answer 44

A condition in which, with repeated exposure to a drug, an individual becomes less responsive to a constant dose Also called tolerance

Question 45

Metabolic tolerance

Answer 45

The form of drug tolerance that arises when repeated exposure to the drug causes the metabolic machinery of the body to become more efficient at clearing the drug

Question 46

Functional tolerance

Answer 46

The form of drug tolerance that arises when repeated exposure to the drug causes receptors to be up-regulated or down-regulated

Question 47

Down-regulation

Answer 47

A compensatory decrease in receptor availability at the synapses of a neuron

Question 48

Up-regulation

Answer 48

A compensatory increase in receptor availability at the synapses of a neuron

Question 49

Cross-tolerance

Answer 49

A condition in which the development of tolerance for one drug causes an individual to develop tolerance for another drug

Question 50

Autoreceptors

Answer 50

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