Study Guide 4

Question 1

What is the effect of excitatory NT binding at the membrane?

Answer 1

• brings closer to depolarization

- AP will occur if threshold is reached

Question 2

What is the effect of inhibitory NT binding at the membrane?

Answer 2

• brings closer to hyperpolarization

- prevents an AP from occurring

Question 3

When does a neuron fire an action potential?

Answer 3

• when threshold is exceeded

- excitatory NTs » depolarization

Question 4

How do agonists impact the channels involved in neurotransmission?

Answer 4

• binds to a receptor and activates it to produce a biological response
• agonist causes action (same action as NT)

Question 5

How do antagonists impact the channels involved in neurotransmission?

Answer 5

blocks the action of the agonist (blocks NT action)

Question 6

What does an inverse agonist do?

Answer 6

Causes an action opposite to that of the agonist

Question 7

How can NTs be removed from the synapse?

Answer 7

• can bind to receptor
• degrade in the synapse (ACh)
• taken up by astrocytes (glutamate)

Question 8

How is an electrical synapse different from a chemical one?

Answer 8

• presynaptic target
• faster transmission
• smaller synapse

Question 9

Electrical synapse: communication between axons

Answer 9

Bidirectional

Question 10

How is a chemical synapse different from an electrical one?

Answer 10

• postsynaptic target
• slower transmission
• larger synapse

Question 11

Which type of synapse do NTs use?

Answer 11

Chemical

Question 12

Which are more common: chemical or electrical synapses?

Answer 12

Chemical

Question 13

What are the macroglia? (Specific cells)

Answer 13

• astrocytes
• oligodendrocytes
• Schwann cells

Question 14

What do macroglia do?

Answer 14

Support and maintain neuronal plasticity

Question 15

What are the microglia?

Answer 15

Immune cells of the brain

Question 16

What does activation of microglia produce?

Answer 16

Produces inflammatory cytokines within the CNS

Question 17

How might aging impact microglia?

Answer 17

• may provide brain environment in which microglia activation continues
• contributes to pathogenesis of neuro dz

Question 18

What makes up the blood brain barrier?

Answer 18

• tight junctions

- surrounded by astrocytes

Question 19

How is the BBB different from other capillaries? (Structure)

Answer 19

• regular capillaries have pores

- no astrocytes

Question 20

What do the tight junctions/astrocytes of the BBB means for membrane transport?

Answer 20

require carrier mediated transport across the membrane

Question 21

To get across the BBB, a substance must be:

Answer 21

• small
• fat soluble (lipophilic)
• hydrophobic (non-polar)

Question 22

What can compromise the BBB?

Answer 22

• trauma

- infection

Question 23

What are some strategies to deliver drugs to the CNS when those drugs are not lipophilic?

Answer 23

• hyperosmosis
• microcatheterization
• microbubbles
• Trojan horse

Question 24

Mannitol =

Answer 24

Diuretic

Question 25

Which drug helps hydrophilic drugs cross the BBB?

Answer 25

Mannitol

Question 26

What happens with hyperosmosis?

Answer 26

• endothelial cells lose H2O and shrink

- space that is left can be used for drug delivery

Question 27

What is microcatheterization?

Answer 27

• small amount of mannitol is delivered to a specific place

- can be used to deliver anti-clotting drugs as well

Question 28

How do microbubbles work for drug delivery?

Answer 28

• fizzy saline
• a beam of US makes them vibrate in a space
• causes opening of barrier

Question 29

How does the Trojan horse method of drug delivery work?

Answer 29

Drug is hidden in a carrier that can cross the BBB