Locomotion

Question 1

Define stepping

Answer 1

Alternating sequence of stance and swing

Question 2

What are central pattern generators and what is their role?

Answer 2

Neural circuits in lumbar spinal cord

Generate rhythmicity of stepping

Question 3

What is the mesencephalic locomotor region and what is its role?

Answer 3

In brainstem - bilaterally innvervates ventral spinal cord via reticular formation
Reticulospinal neurons tonically activate CPGs - control force level of stepping
Alternation/coordination of limbs in each pair - depends on stimulation intensity

Question 4

What is the role of the cerebellum in locomotion?

Answer 4

Avoiding and anticipating obstacles - prediction

Improving stepping performance

Question 5

What is the role of the motor cortex in locomotion?

Answer 5

Cat M1 cells have rhythmic bursts time-locked to stepping movements
Increased activity when stepping over obstacle - required for visually-guided movements
Cat CST involved in locomotion precision

Question 6

What is the role of the posterior parietal cortex in locomotion?

Answer 6

In cats increased firing when stepping over obstacles - increases spinal cord activity

Question 7

What are the 3 components of an integrated control system of locomotion?

Answer 7

Descending control
Spinal CPGs
Peripheral control