Ch. 4 Module 1

Question 1

Axodendritic synapse

Answer 1

begins at the axon terminal and connects to the dendrite

Question 2

Axosomatic synapse

Answer 2

begins at the axon terminal and ends at the soma membrane

Question 3

Axo-axonic synapse

Answer 3

begins at the axon terminal and ends at the axon terminal of a target neuron (has a presynaptic effect)

Question 4

Why is meth the drug of choice compared to cocaine?

Answer 4

Meth lasts much longer as 50% of the drug is removed from the body 12 hours compared to cocaine 50% is removed after 1 hour. In addition, smoking meth produces a long lasting high

Question 5

What kind of PSP will the receptor produce if it binds to a sodium or calcium channel?

Answer 5

EPSP

Question 6

What kind of PSP will be produced if receptors bind to potassium of chloride channels?

Answer 6

IPSP

Question 7

What does the intensity of the PSP depend on?

Answer 7

depends on the amount of neurotransmitters that is released into the cleft

Question 8

What is temporal summation?

Answer 8

input from the same synapse over time

Question 9

What is spatial summation?

Answer 9

input from many different synapses at the same time

Question 10

What are the 3 principles of inotropic receptors:

Answer 10

1. they are rapidly activated
2. they have a local effect
3. they are rapidly terminated

Question 11

What are the effects of protein kinases?

Answer 11

1. produce or block PSP’s
2. activate protein synthesis.

Question 12

What are the response characteristic of Metabotropic receptors:

Answer 12

• delayed onset
• broad effect in membrane
• sustained effect

Question 13

Explain the differences between Iontropic vs Metabotropic Receptors?

Answer 13

Iontropic:
- fast on/off
- all or non on/off
- triggers action potentials
Metabotropic
- slower on/off
- can amplify or dampen signals
- triggers multiple post synaptic events, including action potentials

Question 14

What would happen if we prevent K+ from leaving as quickly as usual?

Answer 14

it would increase the amount of time to produce an action potential due to spike broadening

Question 15

What is the receptor on the terminal that is able to bind with the terminas own transmitter when released

Answer 15

presynaptic autoreceptor

Question 16

What do neuromodulators do?

Answer 16

do not activate synapses, but they do enhance or inhibit the overall function of true synapses in the area.

Question 17

What are synapses called that are directly connected to the next cell?

Answer 17

electrotonic synapse

Question 18

What would happen if you reduced the size of the gap in a synapse? How would this affect transmission?

Answer 18

• if there is a smaller gap, a more effective activation of synapse (potentiation of that synapse)

Question 19

Explain step 1 of LTP

Answer 19

• obtain a baseline measure
• present a single stimulation to the input pathway
• record the synaptic response at the target
• many synapses become active
• this is called the population spike

Question 20

explain step 2 of LTP

Answer 20

• present at high frequency intense stimulation to the input pathway
• known as tetanus
• LTP requires intense stimulation of the synapse

Question 21

Explain step 3 of LTP

Answer 21

• present a single stimulation identical to step 1
• need to compare the population spike from step 2 to baseline
• if LTP occurred, the spike will be larger

Question 22

Explain how electronic conduction occurs?

Answer 22

Occurs at the gap junctions that are typically found in escape circuits or in heart cells that must fire synchronously. They provide rapid responses, but lack the flexibility seen in chemical neurotransmission

Question 23

depolarizing synapses are referred to as what?

Answer 23

Excitatory

Question 24

hyper polarizing synapses are referred to as what?

Answer 24

Inhibitory