Neurobiology - ENC

Question 1

What are the two types of cell death?

Answer 1

1. Necrosis - cell death resulting from injury (ischemia, infection, toxins, etc.).
2. Apoptosis - programmed cell death.

Question 2

What excitotoxins are generated in addition to free radicals and cytotoxic cytokines during necrotic neuronal cell death following acute ischemia or traumatic injury?

Answer 2

1. Glutamate and calcium.

Question 3

What type of cell death occurs in the penumbra after a focal cerebral ischemia?

Answer 3

1. Apoptosis.

Question 4

In chronic neurodegenerative diseases such as Huntington’s, ALS and Alzheimer’s, what is the predominant form of cell death?

Answer 4

1. Apoptosis.

Question 5

At what rate do regenerating axons grow?

Answer 5

1. Approximately 1mm/day.

Question 6

Which filamentous protein polymers serve as the substrate for organelle transport within neurons?

Answer 6

1. Microtubules.

Question 7

Which filamentous protein polymers are important for movement of the advancing tip of growing axons?

Answer 7

1. Microfilaments (actin).

Question 8

Which microtubule-associated ATPase is responsible for anterograde transport?

Answer 8

1. Kinesin.

Question 9

Which microtubule-associated ATPase is responsible for retrograde transport?

Answer 9

1. MAP-1C, a microtubule-associated ATPase similar to dyneins in cilia and flagella.

Question 10

What is the typical resting membrane potential of a neuron?

Answer 10

1. -60 to -70 mV.

Question 11

The resting membrane potential is due to the relatively high permeability of the resting neuronal cell membrane to what ion?

Answer 11

1. Potassium, which has an equilibrium potential of -94mV.

Question 12

How do changes to membrane resistance, membrane conductance, internal (axonal) resistance, and axonal diameter affect the speed of conduction?

Answer 12

The following changes will increase the speed of conduction:

1. Increased membrane resistance.
2. Decreased membrane conductance or capacitance.
3. Decreased internal or axonal resistance.
4. Increased axonal diameter.

Question 13

What are the major amine neurotransmitters?

Answer 13

1. Acetylcholine.
2. Catecholamines (dopamine and NE).
3. Serotonin.

Question 14

What are the major amino acid neurotransmitters?

Answer 14

1. Glutamate.
2. GABA.
3. Glycine.

Question 15

What are some examples of neuropeptide neurotransmitters?

Answer 15

1. Angiotensin II.
2. Endorphins.
3. Substance P.

Question 16

Which neurotransmitters play an excitatory role in the CNS and PNS?

Answer 16

1. CNS: glutamate.

2. PNS: acetylcholine.

Question 17

Which neurotransmitters play an inhibitory role in the CNS?

Answer 17

1. Brain: GABA.

2. Spinal cord: glycine.

Question 18

What is the proposed mechanism for the excitotoxic effect glutamate?

Answer 18

1. Excessive calcium entry through NMDA receptor channels.

Question 19

Where are muscle spindles found?

Answer 19

1. Throughout striated muscle.

Question 20

What do muscle spindles detect?

Answer 20

1. Changes in muscle length.

Question 21

Where are Golgi tendon organs found?

Answer 21

1. At the junction between striated muscle and tendons.

Question 22

What do Golgi tendon organs detect?

Answer 22

1. Changes in muscle tension generated by muscle contraction.