microneurography

Question 1

what is microneurography

Answer 1

enables the recording of neural activity in single sensory axons

Question 2

what type of AP is most commonly seen and why

Answer 2

double hat AP
- artifact of the technique
- recording electrode is usually between 2 nodes on the myelin
- therefore activity is summed from the adjacent nodes

Question 3

what are the most commonly recorded spinal nerves and why

Answer 3

radial, ulnar, median, tibial, and lateral peroneal nerves
- nerve is somewhat exposed (not covered by muscle)

Question 4

what are the 3 techniques to find nerves

Answer 4

palpate - causing pressure on nerve bundle evokes spontaneous APs (funny bone sensation)
ultrasound - image of the nerve directly (most accurate)
electrical current - using a probe tip to pass electrical curretn through the knee and look for region resulting in largest evoked twitch

Question 5

what is the main process of microneurography

Answer 5

1. electrical current to find the nerve
2. identify landmarks
3. electrode insertion
4. enter the nerve (hear burst of neural activity from nerve - pushing into axons = mechanically caused APs)

Question 6

what test is best to determine the difference between primary and secondary muscle spindles and why

Answer 6

ramp and hold stretches
- primary = sensitive to rate (higher dynamic indexes in faster stretches and holds)
- secondary = don’t respond as much to differences in speed

Question 7

what are some modern applications of microneurography

Answer 7

• sensitivity of muscle spindles
• relation between firing rate of muscle spindles and ankle angle
• use in the kinarm
• relation between vibration and firing rate of cutaneous receptors