Chapter 5

Question 1

Two general classes of synapses

Answer 1

Electrical & chemical

Question 2

ELECTRICAL SYNAPSES are the _______ synapse

Answer 2

Minority

Question 3

How do ions in ELECTRICAL SYNAPSES flow?

Answer 3

Bi-directional passive flow between pre and post

Question 4

How do ELECTRICAL SYNAPSES connect neurons?

Answer 4

Gap junctions

Question 5

What does each gap junction have?

Answer 5

Connexons that are made up of 6 connexins

Question 6

How do CHEMICAL SYNAPSES connect neurons?

Answer 6

Synaptic cleft, no touching

Question 7

Structure unique to CHEMICAL SYNAPSES

Answer 7

Synaptic vesicles

Question 8

How do ELECTRICAL and CHEMICAL synapses differ in speed?

Answer 8

ELECTRICAL are very fast without delay, CHEMICAL are slow and elaborate

Question 9

11 step overview of CHEMICAL SYNAPSE transmission

Answer 9

1. transmitter synthesized and stored in vesicle
2. AP reached in pre-synapse
3. Depolarizing of pre opens voltage gated calcium channels
4. calcium influx
5. calcium makes vesicles fuse with pre membrane
6. transmitter released into synaptic cleft via exocytosis
7. transmitter binds to post receptor
8. open or close of post channels
9. post current either excites or inhibits post cell
10. transmitter removed by glial uptake or enzymatic degradation
11. vesicle retrieved back inside pre

Question 10

What is exocytosis?

Answer 10

Transmitter released into cleft through vesicle fusing with pre-synaptic membrane

Question 11

Otto Loewi’s experiment demonstrated what and how?

Answer 11

The presence of a chemical signal through a seminal experiment of two hearts and the traveling of molecules

Question 12

What is the role of Ca2+ in synaptic transmission?

Answer 12

Calcium channels are opened when AP is reached, calcium then triggers exocytosis and released transmitter into cleft, LEADS TO RELEASE OF NEUROTRANSMITTER

Question 13

The four criteria for a neurotransmitter

Answer 13

Present in pre-synapse, released during depolarization, calcium dependent, has receptors on the post-synaptic cell

Question 14

The two types of neurotransmitters?

Answer 14

Small-molecule and peptide

Question 15

Small-molecule transmitters are created WHERE, HOW and INTO WHAT?

Answer 15

Synthesized in PRE-SYNAPSE, by ENZYMES sent via SLOW axonal transport, packaged into SMALL CLEAR-core vesicles

Question 16

Peptide transmitters are created WHERE, HOW, and INTO WHAT?

Answer 16

Synthesized in RER/GOLGI, sent to pre by FAST axonal transport, packaged into LARGE DENSE-core vesicles

Question 17

Two types of neurotransmitter receptors?

Answer 17

Ionotropic & Metabotropic

Question 18

IONOTROPIC receptors include _______ and produce a _______ response.

Answer 18

ligand gated ion channels, FAST

Question 19

METABOTROPIC receptors include _______, and produce a ______ response

Answer 19

g-protein coupled receptors, SLOW

Question 20

Main differences between IONOTROPIC and METABOTROPIC receptors?

Answer 20

Ionotropic span across membrane and form ion channels, metabotropic do not have ion channels.
Ionotropic combine transmitter binding and channel, metabotropic depends on metabolic steps and interacts with intermediate molecules.

Question 21

How do PSPs affect AP?

Answer 21

Alters if AP will be produced or not

Question 22

How do EPSPs affect AP?

Answer 22

Increases chance of AP

Question 23

How do IPSPs affect AP?

Answer 23

Decreases chance of AP

Question 24

If reverse potential > threshold, the cell is?

Answer 24

Excitatory

Question 25

If reverse potential < threshold, the cell is?

Answer 25

Inhibited

Question 26

What does summation do?

Answer 26

EPSPs and IPSPs may sum together to modulate post neuron