1. The basic reflex arc and spinal cord circuitry

2. Basic Spinal Anatomy
Transversal cut of the spinal cord

3. Basic Spinal Anatomy Muscle spindles Motoneurons targetting muscles
Golgi tendon organs
Soma of the motoneurons
Sensory information
Tactile, pain, thermic receptors on the skin

4. ? How is the sensory-motor circuitry organized? Sensory input
Motor output

5. Stretch reflex
Reciprocal innervation and synergist connections

6. Stretch reflex Reciprocal innervation and synergist connections
Simplify the commands from higher levels necessary to control of voluntary movements
Corticospinal connexions can modulate the reciprocal connectivity

7. Stretch reflex Reciprocal innervation and synergist connections
Simplify the commands from higher levels necessary to control of voluntary movements
Corticospinal connexions can modulate the reciprocal connectivity

8. Withdrawal reflex Reciprocal innervation and synergist connections
Simplify the commands from higher levels necessary to control of voluntary movements
Corticospinal connexions can modulate the reciprocal connectivity
Cross-connections
Coordination necessary for the control of posture

9. Vertical Connections Reciprocal innervation and synergist connections
Simplify the commands from higher levels necessary to control of voluntary movements
Corticospinal connexions can modulate the reciprocal connectivity
Cross-connections
Coordination necessary for the control of posture

10. Convergence of sensory informations
Reciprocal innervation and synergist connections
Simplify the commands from higher levels necessary to control of voluntary movements
Corticospinal connexions can modulate the reciprocal connectivity
Cross-connections
Coordination necessary for the control of posture
Convergence of sensory input

11. Are reflexes streotyped ?
Corticospinal connections can shape the reflexes in order to adapt to different contexts

12. Conclusion
Spinal cord circuitry forms the infrastructure that is exploited
by supraspinal areas in order to coordinat different muscle
The input output relation is far from a streotyped relation
Since it can be shaped in order to adapt to the behavioral
states of the organism