Synaptic Transmission

Question 1

Functional contacts between neurons, or between neurons and target tissues such as muscle fibers

Answer 1

Synapses

Question 2

refers to the propagation of nerve impulses from one nerve cell to another, or to non-neuronal cells such as muscles or glands

Answer 2

Synaptic Ttansmission

Question 3

Cells are continuous, allowing direct current flow;

Answer 3

Electrical synapses

Question 4

There are discrete presynaptic and postsynaptic cells. The presynaptic cells release a chemical substance which binds to receptors in the postsynaptic cells and initiates current flow;

Answer 4

Chemical Synapses

Question 5

What are the 2 advantages of electrical synapses?

Answer 5

Very rapid, transmission consists only of the direct flow of current (~0.1 msec synaptic delay)
Can coordinate large population of neurons to act in synchrony

Question 6

What are the 2 disadvantages of electrical synapses?

Answer 6

Tend to be mainly excitatory, harder to regulate

fine control of synaptic transmission not possible

Question 7

1. Transmitter is synthesized and stored in _______

Answer 7

synaptic vesicle

Question 8

2. Action potential invades the _______

Answer 8

presynaptic terminal

Question 9

3. ______ of presynaptic terminal causes opening of voltage-gated Ca2+ channels

Answer 9

Depolarization

Question 10

4. Influx of _____ through channels

Answer 10

Ca2+

Question 11

5.Ca2+ causes vesicles to fuse with ______

Answer 11

presynaptic membrane

Question 12

6.Transmitter is released into _____ via ______

Answer 12

synaptic cleft; exocytosis

Question 13

7.Transmitter binds to receptors on ______

Answer 13

postsynaptic membrane

Question 14

8.Transmitter causes opening or closing of ______

Answer 14

postsynaptic channels

Question 15

9.Postsynaptic current causes excitatory or inhibitory postsynaptic potential that changes the _______ of the postsynaptic cell.

Answer 15

excitability

Question 16

10. Transmitter is cleared from the cleft via ____, ______, or ______

Answer 16

diffusion, re-uptake or enzymatic breakdown

Question 17

11.______ is retrieved from the plasma membrane.

Answer 17

Vesicular membrane

Question 18

Increase the resting membrane potential (depolarize) by increasing the conductance of Na+ or Ca2+ ions or by decreasing the conductance of K+ ions

Answer 18

Excitatory Synapses

Question 19

Hyperpolarizes the membrane potential
(more negative than rest) by increasing
the conductance of K+ or Cl- ions

Answer 19

Inhibitory synapses

Question 20

the additive effect produced by successive synaptic currents at one synapse

Answer 20

Temporal summation

Question 21

the additive effectproduced by synaptic currents originatingat more than one synapse

Answer 21

Spatial summation

Question 22

4 mechanisms that rapidly terminate the actions of the chemical:

Answer 22

Re-uptake at terminal
Enzymatic breakdown
Diffusion
Uptake by glial cells

Question 23

receptor is an integral part of the ion channel that it regulates
neurotransmitter binding changes channel gating

Answer 23

Ionotropic receptors (Directly gated channels)

Question 24

receptor is distinct from the ion channels it regulates

neurotransmitter binding activates G-protein cascade that eventually alters channel gating

Answer 24

Metabotropic receptors (Indirectly gated channels)

Question 25

Primarily mediated by ligand-gated ion channels

Answer 25

Fast Post Synaptic Potential

Question 26

Primarily mediated by metabotropic receptors

Answer 26

Slow Post Synaptic Potential

Question 27

modulated indirectly following changes in the metabolic machinery of the cell

Answer 27

Ionic conductance(s)

Question 28

Gs

Answer 28

Adenylate cyclase
Increase in cAMP
increase in PKA - protein phosphorylation

Question 29

Gi

Answer 29

Adenylate cyclase
decrease in cAMP
decrease in PKA - protein dephosphorylation

Question 30

Go/q (1)

Answer 30

PLC
IP3, DAG, Ca2+
PKC - protein phosphorylation

Question 31

Go/q (2)

Answer 31

PLA2
Arachidonic acid
Protein kinases, etc.