Lecture 10 - Motor pattern generation (2)

Question 1

What are spinal cord alpha-motorneurons controlled by?

Answer 1

• Proprioceptive input
• Descending pathways
• Local/spinal interneurons (CPG)

Question 2

What form does the CPG circuitry take in Lamprey to allow swimming?

Answer 2

• Two CPGs
• Set up two simultaneous cycles
• Both inhibit each other

Question 3

How are the spinal interneurons of lamprey activated?

Answer 3

• Calcium activated potassium channels
• NMDA receptors
• Glutamate binds to NMDA receptors
• Ca2+ and Na+ rushes in

Question 4

What does changing gait involve?

Answer 4

• Changes function output from CPG

- Altered cycle frequency and phase relationships

Question 5

What are features of the Stomatogastric system of Crustacea?

Answer 5

• Rhythmic movement of different regions of the foregut
• Controlled by striated muscles
• Each part can operate independently and outputs are very flexible

Question 6

How do Neuromodulators effect the CPG?

Answer 6

Exert differential effects on the cellular, synaptic, ad network of the CPG

Question 7

How do neuromodulators effect the cellular part of the CPG?

Answer 7

Alter excitability

Question 8

How do neuromodulators effect the synaptic part of the CPG?

Answer 8

Strengthen or weaken synaptic transmission

Question 9

How do neuromodulators effect the network part of the CPG?

Answer 9

May add or remove specific cellular or synaptic components from the network

Question 10

How does sensory feedback help configure the CPG?

Answer 10

• Helps time the switch between phases of the rhythm

- Helps coordinate adjacent limbs

Question 11

What is evidence for spinal CPG in humans?

Answer 11

Infants can produce rhythmic stepping

Question 12

What are potential treatments for spinal cord injuries?

Answer 12

• Electrical stimulation
• Pharmacological
• Embryonic neural tissue transplant