How do neurons use electrochemical signals to communicate and adapt?

Question 1

synaptic vesicle

Answer 1

Organelle consisting of a membrane structure that encloses a quantum of neurotransmitter.

Question 2

acetylcholine (ACh)

Answer 2

First neurotransmitter discovered in the peripheral and central nervous systems; activates skeletal muscles in the somatic nervous system and may either excite or inhibit internal organs in the autonomic system.

Question 3

nitric oxide (NO)

Answer 3

Gas that acts as a chemical neurotransmitter-for example, to dilate blood vessels, aid digestion, and activate cellular metabolism.

Question 4

habituation

Answer 4

Learning behavior in which a response to a stimulus weakens with repeated stimulus presentations.

Question 4

ionotropic receptor

Answer 4

Embedded membrane protein that acts as (1) a binding site for a neurotransmitter and (2) a pore that regulates ion flow to directly and rapidly change membrane voltage.

Question 4

presynaptic membrane

Answer 4

Membrane on the transmitter-output side of a synapse (axon terminal).

Question 5

major depression

Answer 5

Mood disorder characterized by prolonged feelings of worthlessness and guilt, the disruption of normal eating habits, sleep disturbances, a general slowing of behavior, and frequent thoughts of suicide.

Question 6

gamma-aminobutyric acid (GABA)

Answer 6

Amino acid neurotransmitter that inhibits neurons.

Question 6

synaptic cleft

Answer 6

Gap that separates the presynaptic membrane from the postsynaptic membrane.

Question 7

histamine (H)

Answer 7

Neurotransmitter that controls arousal and waking; can cause the constriction of smooth muscles and so, when activated in allergic reactions, contributes to asthma, a constriction of the airways.

Question 9

carbon monoxide (CO)

Answer 9

Gas that acts as a neurotransmitter in the activation of cellular metabolism.

Question 10

learning

Answer 10

Relatively permanent change in behavior that results from experience.

Question 11

metabotropic receptor

Answer 11

Embedded membrane protein, with a binding site for a neurotransmitter but no pore, linked to a G protein that can affect other receptors or act with second messengers to affect other cellular processes.

Question 11

transporter

Answer 11

Protein molecule that pumps substances across a membrane.

Question 12

rate-limiting factor

Answer 12

Any enzyme that is in limited supply, thus restricting the pace at which a chemical can be synthesized.

Question 13

schizophrenia

Answer 13

Behavioral disorder characterized by delusions, hallucinations, disorganized speech, blunted emotion, agitation or immobility, and a host of associated symptoms.

Question 14

Parkinson’s disease

Answer 14

Disorder of the motor system correlated with a loss of dopamine in the brain and characterized by tremors, muscular rigidity, and reduction in voluntary movement.

Question 16

cholinergic neuron

Answer 16

Neuron that uses acetylcholine as its main neurotransmitter. The term cholinergic applies to any neuron that uses ACh as its main transmitter.

Question 17

G protein

Answer 17

Guanyl-nucleotide-binding protein coupled to a metabotropic receptor that, when activated, binds to other proteins.

Question 19

gap junction (electrical synapse)

Answer 19

Fused prejunction and postjunction cell membrane in which connected ion channels form a pore that allows ions to pass directly from one neuron to the next.

Question 20

small-molecule transmitter

Answer 20

Quick-acting neurotransmitter synthesized in the axon terminal from products derived from the diet.

Question 21

autoreceptor

Answer 21

“Self-receptor” in a neural membrane that responds to the transmitter released by the neuron.

Question 21

postsynaptic membrane

Answer 21

Membrane on the transmitter-input side of a synapse (dendritic spine).

Question 22

serotonin (5-HT)

Answer 22

Amine neurotransmitter that plays a role in regulating mood and aggression, appetite and arousal, the perception of pain, and respiration.

Question 24

neurotransmitter

Answer 24

Chemical released by a neuron onto a target with an excitatory or inhibitory effect.

Question 25

sensitization

Answer 25

Learning behavior in which the response to a stimulus strengthens with repeated presentations of that stimulus because the stimulus is novel or because the stimulus is stronger than normal-for example, after habituation has occurred.

Question 26

neuropeptide

Answer 26

Multifunctional chain of amino acids that acts as a neurotransmitter; synthesized from mRNA on instructions from the cell’s DNA. Peptide neurotransmitters can act as hormones and may contribute to learning.

Question 27

transmitter-activated receptor

Answer 27

Protein that has a binding site for a specific neurotransmitter and is embedded in the membrane of a cell.

Question 28

dopamine (DA)

Answer 28

Amine neurotransmitter that plays a role in coordinating movement, in attention and learning, and in behaviors that are reinforcing.

Question 28

storage granule

Answer 28

Membranous compartment that holds several vesicles containing a neurotransmitter.

Question 30

posttraumatic stress disorder (PTSD)

Answer 30

Syndrome characterized by physiological arousal symptoms related to recurring memories and dreams related to a traumatic event for months or years after the event.

Question 31

mania

Answer 31

Disordered mental state of extreme excitement.

Question 31

reuptake

Answer 31

Deactivation of a neurotransmitter when membrane transporter proteins bring the transmitter back into the presynaptic axon terminal for subsequent reuse.

Question 33

norepinephrine (NE, or noradrenaline)

Answer 33

Neurotransmitter found in the brain and in the sympathetic division of the autonomic nervous system; accelerates heart rate in mammals.

Question 34

glutamate (Glu)

Answer 34

Amino acid neurotransmitter that excites neurons.

Question 36

quantum (pl. quanta)

Answer 36

Amount of neurotransmitter, equivalent to the contents of a single synaptic vesicle, that produces a just observable change in postsynaptic electric potential.

Question 37

activating system

Answer 37

Neural pathways that coordinate brain activity through a single neurotransmitter; cell bodies are located in a nucleus in the brainstem and axons are distributed through a wide region of the brain.

Question 38

second messenger

Answer 38

Chemical that carries a message to initiate a biochemical process when activated by a neurotransmitter (the first messenger).

Question 39

Alzheimer’s disease

Answer 39

Degenerative brain disorder related to aging that first appears as progressive memory loss and later develops into generalized dementia.

Question 40

chemical synapse

Answer 40

Junction at which messenger molecules are released when stimulated by an action potential.

Question 41

epinephrine (EP, or adrenaline)

Answer 41

Chemical messenger that acts as a hormone to mobilize the body for fight or flight during times of stress and as a neurotransmitter in the central nervous system.

Question 42

obsessive-compulsive disorder (OCD)

Answer 42

Behavior disorder characterized by compulsively repeated acts (such as hand washing) and repetitive, often unpleasant, thoughts (obsessions).

Question 43

noradrenergic neuron

Answer 43

From adrenaline, Latin for ‘epinephrine’; a neuron containing norepinephrine.