1. Somatosensory System and Pain Prof. Marshall Devor, Ph.D. Dept. of Cell & Animal Biology and Center for Research on Pain Institute of Life Sciences Hebrew University of Jerusalem lecture 4: Afferent input to the spinal cord 08-9 פיסיולוגיה מורחב 08-9 פיסיולוגיה מורחב

2. flexor reflex flexor reflex afferents nociceptors multisegmental response Collateral branching flexion  extension  nociceptive afferent

3. segmental reflex flexor reflex

4. primary sensory neurons

6. D V rostral caudal rostral cranial cervical thoracic lumbar sacral coccygeal caudal somatotopic mapping (note overlapping RFs)

7. substantia gelatinosa

8. Rexed laminae ventral horn dorsal horn A  Aδ C

9. SP NK1 substance P – neurotransmitter/ neuromodulator neurokinin 1 (NK1) SP receptor

10. somatotopic mapping Rexed’s laminae divergence convergence

12. dermatome L6 L4 L1 T10 T11 T10-T11 overlap dermatome somatotopic map

13. trigeminal system V1,V2,V3 V = 5 th cranial nerve opthalmic division maxillary division mandibular division caudal trigeminal nucleus = dorsal horn of V

14. proximal distal somatotopic map Med. Lat. rostral caudal fore hind proximo-distal rostro-caudal

15. succinyl dehydrogenase somatosensory mapping

16. somatotopic mapping Rexed’s laminae divergence convergence

17. BT+P+ P- WDR multireceptive some SG neurons are "nociceptive specific" X low threshold specific Rexed’s laminae

18. synaptic input into the dorsal horn

19. divergence

20. Divergence SA1

22. Convergence

25. divergence convergence

26. Somatosensory System and Pain Prof. Marshall Devor, Ph.D. Dept. of Cell & Animal Biology and Center for Research on Pain Institute of Life Sciences Hebrew University of Jerusalem lecture 4: Afferent input to the spinal cord פיסיולוגיה מורחב

27. myotactic (stretch) reflex …demo simple behavior Polysynaptic antagonist muscle (inhibitory interneuron) Monosynaptic agonist muscle Muscle spindle כישור שריר Muscle spindle afferent (DRG)