1. Interdisciplinary Program in Neuroscience Eye Movement & Vision Research LAB Hwang, Jae Won Somatosensory Sensation & Motor Functions

2. Somatosensory Sensation  Somatosensory Sensation –Modalities –Receptors –Somatosensory Pathways –Somatosensory Cortex  Motor Functions  Disorders

3. Somatosensory Modalities  Touch  Proprioception  Nociception  Temperature Sense

4. Morphology of DRG Cell Ref. 1. Ch 22 p. 431

5. Mechanoreceptors (touch) Ref. 1. Ch 22 p. 433

6. Mechanoreceptors (proprioception) Ref. 1. Ch 21 p. 415

7. Receptor Types Ref. 1. Ch 22 p. 432

8. Receptive Field (touch) Ref. 1. Ch 22 p. 434

9. Two Point Discrimination Ref. 1. Ch 22 p. 436

10. Distribution of Dermatomes Ref. 1. Ch 22 p. 445

11. Spinal Cord Ref. 1. Ch 18 p. 339 & Ref. 2. Ch 3 p.76

12. Touch & Proprioception(joint) Pathway Ref. 3. http://thalamus.wustl.edu/course/bassens.htmlhttp://thalamus.wustl.edu/course/bassens.html

13. Decussation of Medial Lemnisci Ref. 2. Ch 5 p. 195

14. Proprioception(muscle & tendon) Pathway Ref. 3. http://thalamus.wustl.edu/course/body.htmlhttp://thalamus.wustl.edu/course/body.html

15. Nociceptive Afferent Fibers Ref. 1. Ch 24 p. 473-474

16. Pain & Temperature Pathway Ref. 3. http://thalamus.wustl.edu/course/body.htmlhttp://thalamus.wustl.edu/course/body.html

17. Sensory Pathways (summary) Ref. 1. Ch 22 p. 447

18. Sensory Pathways (summary) Ref. 1. Ch 22 p. 447

19. Comparison of sensory pathway description among the references Decussation of Medial Lemnisci Spinocerebellar Anterolater (spinothalamic) Ref. 1 Touch & Proprioception Pain & Temperature Ref. 2 Discriminative touch, Vibration, & Proprioception Light Touch & Pressure Pain & Temperature Ref. 3 Discriminative touch Proprioception Pain & Temperature

20. Ascending & Descending Tracts Ref. 2. Ch 4 p. 145

21. Segmental Organization of SC Ref. 2. Ch 4 p. 168

22. Thalamus Ref. 1. Ch 18 p. 343

23. Somatosensory Cortex Ref. 1. Ch 23 p. 453

24. RF of Cell in a Column in SSC Ref. 1. Ch 23 p. 456

25. Receptive Fields of Neurons in SSC Ref. 1. Ch 23 p. 455

26. Columnar Organization of Sensory Input Ref. 1. Ch 23 p. 459

27. Sensory Homunculus Ref. 1. Ch 18 p. 344

28. Processing of Sensory Information Ref. 1. Ch 18 p. 345

29. Motor Functions  Somatosensory Sensation  Motor Functions –Brain Structures Involved in Motor Control –Motor Pathways –Motor Neurons –Neuromuscular Junction  Disorders

30. Motor Cortices Ref. 4. Ch 4 p. 144 & Ref. 1. Ch 38 p. 760

31. Flow of Motor Information Ref. 1. Ch 19 p. 356

32. Supplementary & Premotor Areas Ref. 1. Ch 38 p. 773

33. Parietal Cortex Ref. 4. Ch 4 p.148 & Ref. 1. Ch 28 p. 567

34. Command Flow of Left PL Ref. 5. Ch 8 p. 216

35. Cerebellum Ref. 1. Ch 42 p. 835

36. Basal Ganglia Ref. 1. Ch 43 p. 856

37. Corticospinal Tract Ref. 3. http://thalamus.wustl.edu/course/basmot.htmlhttp://thalamus.wustl.edu/course/basmot.html anterior corticospinal tract (about 10%)lateral corticospinal tract

38. Pyramidal Decussation Ref. 2. Ch 5 p. 195

39. Corticospinal Tract Ref. 1. Ch 18 p. 346

40. Corticospinal Tract Ref. 1. Ch 18 p. 346

41. Corticobulbar & Rubrospinal Tracts Ref. 5. Ch 8 p. 212

42. Ventromedial Pathways Ref. 5. Ch 8 p. 213

43. Motor Neurons Ref. 2. Ch 4 p. 165

44. Neuromuscular Junction Ref. 1. Ch 11 p. 188

45. Disorders  Somatosensory Sensation  Motor Functions  Disorders –Spinal Cord Syndromes –Phantom Limb –Agnosia & Apraxia –Subcortical Motor Disorders –Neurogenic Diseases of Motor Unit

46. Spinal Cord Syndromes Ref. 2. Ch 4 p. 173

47. Phantom Limb Ref. 1. Ch 20 p. 393

48. MEG of Amputee Ref. 6. Ch 2 p. 32 & Ref. 7. p. 1610

49. Agnosia  The Inability to perceive or identify a stimulus by means of a particular sensory modality, even though its details can be detected by means of that modality and the person retains relatively normal intellectual capacity –Apperceptive visual agnosia  People with apperceptive visual agnosia may have normal visual acuity, but they cannot successfully recognize objects visually by their shape.  Prosopagnosia ( Prosopon means “face”) –Associative visual agnosia  People with associative visual agnosia appear to be able to perceive normally but cannot name what they have seen.

50. Example of Agnosia Ref. 1. Ch 62 p. 1235

51. Apraxia  The inability to properly execute a learned skilled movement –Limb apraxia –Constructional apraxia –Oral apraxia –Apraxic agraphia

52. Limb Apraxias  Limb apraxia is character- ized by movement of the wrong part of the limb, incorrect movement of the correct part, or correct mevements but in the incorrect sequence. Ref. 5. Ch 8 p. 215

53. Constructional Apraxia  The primary deficit in constructional apraxia appears to involve the ability to perceive and imagine geometrical relations.  Dressing Apraxia Ref. 5. Ch 8 p. 216

54. Balint’s syndrome  Balint’s syndrome occurs in people with bilateral damage to posterior parietal and prestriate cortex.  Balint’s syndrome consists of three major symptoms. –Optic ataxia (ataxia comes from the Greek word for “disorderly”)  A person with BS might be able to perceive and recognize a particular object, but when he or she tries to reach for it, the movement is often misdirected. –Ocular apraxia (“without visual action”)  If an object moves, or if a light flashes, the person with BS may report seeing something but will not be able to make an eye movement that directs the gaze toward the target. –Simultanagnosia  If the gaze of a person with BS happens to fall on an object, he or she will perceive it. But only one object will be perceived at a time. Ref. 5. Ch 6 p. 163

55. Hemineglect Ref. 1. Ch 20 p. 394-396

56. Parkinson’s Disease Ref. 1. Ch 43 p. 860

57. Huntington’s Disease Ref. 1. Ch 43 p. 860

58. Diseases of the Motor Unit Ref. 1. Ch 35 p. 697

59. Myasthenia Gravis Ref. 1. Ch 16 p. 299

60. References 1. Eric R. Kandel, James H. Schwartz, Thomas M. Jessell (2000) Principles of Neural Science, 4th ed. New York, NY: McGraw-Hill 2. Richard S. Snell (2001) Clinical neuroanatomy for medical students, 5th ed. Baltimore, MD: Lippincott Williams & Wilkins 3. Diani W. Molavi (1997) Neuroscience tutorial Retrieved from WWW April 19, 2003. http://thalamus.wustl.edu/course/ http://thalamus.wustl.edu/course/ 4. Marie T. Banich (1997) Neuropsychology Boston, MA: Houghton Miffin 5. Neil R. Carson (1995) Foundations of physiological psychology, 3rd ed. Needham, MA: Allyn & Bacon 6. V.S. Ramachandran, Sandra Blakeslee (1998) Phantoms in the brain New York, NY: HarperCollins 7. Ramachandran VS, Hirstein W. (1998) The perception of phantom limbs. The D. O. Hebb lecture Brain, 121, 1603-1630