1. Motor Systems 1. Spinal Reflexes
2. Central Pattern Generators in spine and brainstem
3. Motor Cortex and Basal Ganglia

2. Central Pattern Generator
Locomotion, chewing, swallowing, breathing, etc.

3. Central Pattern Generator Properties
1. Multiple neurons -- not a simple reflex loop
2. Motor patterns produced by different combinations
of neurons or recruitment of neurons
3. CPGs have oscillatory activity
4. Defined by “fictive locomotion”
5. CPGs localized in brainstem/spinal cord by transections
6. Properties modulated by central or peripheral input
7. CPGs not necessarily conserved across species
(but properties of neurons are conserved across species).

4. Walking

5. <--- Glutamate

6. The Generation of Spinal Motor Programs for Walking
Rhythmic Oscillation

7. The Generation of Spinal Motor Programs for Walking

8. Walking

10. Central Pattern Generator: Lamprey swimming

11. Lamprey Spinal Cord Fictive Movement Fictive movement:
Cord “swims” in absence of sensory input, muscles
Rhythmic pattern

12. Lamprey Spinal Network

13. Walking

14. Walking

15. Swimming vs. Walking:
Swimming = fast, traveling wave (hips, shoulders wiggle)
Walking = slow, standing wave (hips, shoulders stay in line)
Change in pattern -> change in locomotion

16. Locomotion in spinal cat
localized to spinal cord

17. Decerebrate Cat walks on all four limbs if stimulated
Fictive walking:
note contribution of afferent feedback
Fictive Movement

18. Isolated Neonatal Rat spinal cord

19. Central Pattern Generator
Control of CPG output
Locomotion, chewing, swallowing, breathing, etc.

21. Descending Modulation of CPG

22. Descending Modulation of CPG
stimulate midbrain

23. Central Pattern Generator Properties
1. Multiple neurons -- not a simple reflex loop
2. Motor patterns produced by different combinations
of neurons or recruitment of neurons
3. CPGs have oscillatory activity
4. Defined by “fictive locomotion”
5. CPGs localized in brainstem/spinal cord by transections
6. Properties modulated by central or peripheral input
7. CPGs not necessarily conserved across species
(but properties of neurons are conserved across species).