unit 3 - pt1. Neurons & synapses

Question 1

Electrical signals are within a neuron and include

Answer 1

1. Local potentials (in dendrites and soma)
2. Action potentials (down axon)

Question 2

Chemical signals are located between neurons and include

Answer 2

neurotransmitters

Question 3

A resting neuron is

Answer 3

polarized (difference in electrical charge ions inside vs outside of cell)

Question 4

Ions are

Answer 4

electrically charged molecules

Question 5

anions are

Answer 5

negatively charged

Question 6

cations are

Answer 6

positively charged

Question 7

The resting potential of a neuron is around

Answer 7

-70 millivolts (mV)

Question 8

The resting potential (Ionic basis) is close to

Answer 8

the equilibrium potential for K+

Question 9

Electrical pressure for potassium (K+) to enter cell, but

Answer 9

chemical pressure to leave cell

Question 10

Electrical and chemical pressure for sodium (Na+) and

Answer 10

calcium (Ca++) to enter cell

Question 11

Chemical pressure for chloride (CL-) to

Answer 11

enter cell

Question 12

ion channels may be opened by several triggers, including (4)

Answer 12

1. Ligand binding
2. change in membrane potential
3. phosphorylation
4. G proteins

Question 13

Inhibitory post-synaptic potential (IPSP) =

Answer 13

hyperpolarization from K+ or CL- channels opening

Question 14

Excitatory post-synaptic potential (EPSP) =

Answer 14

depolarization from Na+ channels opening

Question 15

threshold (about -40 mV), triggers a

Answer 15

brief action potential (or spike)

Question 16

(During action potential) The membrane potential reverses, and the inside of the cell becomes

Answer 16

positive

Question 17

The action potential is caused by a sudden rush of Na+ ions into the

Answer 17

axon

Question 18

Voltage-gated Na+ channels conduct the

Answer 18

action potential down the axon

Question 19

Local potentials (ESPS & IPSPS) are depolarization or hyperpolarization VS action potentials which are just

Answer 19

depolarization

Question 20

Synapse (to clasp or join) is the site of

Answer 20

action for most psychoactive drugs

Question 21

(presynaptic synapse)
The axon terminal contains synaptic vesicles that contain

Answer 21

neurotransmitter

Question 22

(postsynaptic synapse)
What responds to the neurotransmitters?

Answer 22

Receptors

Question 23

• Amino acids (Glu, GABA)
• Monoamines (DA, NE, 5-HT)
• Acetylcholine
• Purines

Answer 23

Classical neurotransmitters

Question 24

• Neuropeptides (opioids)
• Lipids
• Gases

Answer 24

non-classical neurotransmitters (no vesicles)

Question 25

3 steps in chemical synaptic transmission

Answer 25

1. synthesis 2. release 3. inactivation

Question 26

Classical NTs are synthesized from

Answer 26

dietary precursors

Question 27

Enzymes in the ??? synthesize the NTs and then are transported into the small vesicles

Answer 27

axon terminals

Question 28

Neuropeptides are synthesized in the ???, packaged into large vesicles, and then transported. What is this process called? What else can they release?

Answer 28

- cell body - protein-synthesis dependent - classical transmitters

Question 29

Classical NTs require

Answer 29

active transport

Question 30

Vesicular transporters move transmitters into

Answer 30

vesicles

Question 31

Vesicle fusion with cell membrane is mediated by

Answer 31

SNARE proteins

Question 32

Botulinum toxin cleaves SNARE proteins involved in vesicle fusion

Answer 32

Botox

Question 33

vesicle membrane is retrieved from the terminal membrane

Answer 33

endocytosis

Question 34

New (empty) vesicles can be refilled with NT rapidly =

Answer 34

vesicle recycling

Question 35

Neurotransmitter binds to receptors on the

Answer 35

postsynaptic side

Question 36

These receptors can be what or what

Answer 36

ionotropic (ligand-gated ion channels) or metabotropic (G protein-coupled receptors)

Question 37

Neurotransmitter also binds to autoreceptors on the what side

Answer 37

presynaptic

Question 38

Autoreceptors are receptors on the same neuron releasing NT and they provide

Answer 38

feedback (usually negative)

Question 39

What kind of autoreceptor modulates NT release? What kind or autoreceptor modulates NT synthesis or firing?

Answer 39

- Terminal - Somatodendritic

Question 40

Nts are inactivated via

Answer 40

1. Rapid ENZYMATIC DEGRADATION (metabolism via enzymes) OR 2. PLASMA MEMBRANE TRANASPORTERS located in the nerve terminal , REUPTAKE, or glia

Question 41

Are transporters in inactivation different than vesicular transporters?

Answer 41

YES

Question 42

Retrograde transmission is signaling from

Answer 42

post-synaptic to pre-synaptic cell (diff than anterograde transmission used in most signaling)

Question 43

Gases and lipids pass through membranes and signal to the ? No what?

Answer 43

presynaptic terminal (NO VESICLES)