Blumenfeld – Chapter 18 Limbic System: Homeostasis, Olfaction, Memory, and Emotion

1. Blumenfeld – Chapter 18Limbic System: Homeostasis, Olfaction, Memory, and Emotion Chenjie Xia (R2) Academic ½ Day Wednesday, April 7th, 2010

2. Review of key structures

3. Overview of limbic structures

4. Overview of limbic structures

5. Overview of limbic structures

6. Limbic structures • Amygdala nuclei • Corticomedial, basolateral, central, bed nucleus of the stria terminalis • Diencephalon • Hypothalamus, thalamus (anterior and mediodorsal nuclei), habenula • Basal ganglia • Ventral striatum, ventral pallidum

7. Limbic structures • Basal forebrain • Nucleus basalis of Meynert, olfactory tubercle, nucleus of diagonal band of Broca, preoptic area, portions of amygdala • Septal Region • Medial septal nucleus, lateral septal nucleus, nucleus accumbens • Brainstem nuclei • Interpeduncular, superior central, dorsal and ventral tegmental, parabrachial, periaqueductal gray, reticular formation, nucleus solitarius, dorsal motor nucleus of vagus

8. Overview of limbic circuitry

9. The Return of Neuro-Jeopardy! (No more Meryl Streep questions…)

10. Neuro-Jeopardy 100 100 100 100 200 200 200 200 300 300 300 300 400 400 400 400 500 500 500 500

11. Clinical Anatomy

12. Clinical Anatomy 100 • Where did Dr. Brenda Milner obtain her undergraduate degree and what did she major in? • A) Oxford, philosophy • B) Cambridge, psychology • C) McGill, physiology • D) University of Montreal, biology

13. Clinical Anatomy 100 • Where did Dr. Brenda Milner obtain her undergraduate degree and what did she major in? • A) Oxford, philosophy • B) Cambridge, psychology • C) McGill, physiology • D) University of Montreal, biology

15. Clinical Anatomy 200 • Bilateral lesions of medial temporal and diencephalic structures would impair which of the following? • A) Mediate working memory • B) Consolidate long-term explicit memory • C) Consolidate long-term implicit memory • D) Retrieve long-term explicit memory • E) Retrieve long-term implicit memory

16. Clinical Anatomy 200 • Bilateral lesions of medial temporal and diencephalic structures would impair which of the following? • A) Mediate working memory • B) Consolidate long-term explicit memory • C) Consolidate long-term implicit memory • D) Retrieve long-term explicit memory • E) Retrieve long-term implicit memory

18. Clinical Anatomy 300 • Name 2 intracerebral vascular lesions which could lead to memory deficits

19. Clinical Anatomy 300 • Rupture of A-com aneurysm (disrupt basal forebrain, medial diencephalon, and frontal lobes) • Top of the basilar artery lesions (b/l medial temporal or medial diencephalic supplied by PCA) • Artery of Percheron lesion / single paramedian thalamoperforator artery (b/l medial thalami)

20. Clinical Anatomy 300 http://www.ajnr.org/cgi/content-nw/full/24/10/2005/F4

22. Clinical Anatomy 400 • Which function has Dr. Brenda Milner has discovered for each of the following structures? • 1) Medial temporal lobes • 2) Right temporal lobe • 3) Left frontal lobe • 4) Dorsolateral frontal lobes

23. Clinical Anatomy 400 • Which function has Dr. Brenda Milner discovered for each of the following structures? • 1) Medial temporal lobes  explicit memory • 2) Right temporal lobe  visuospatial memory • 3) Left frontal lobe  verbal fluency • 4) Dorsolateral frontal lobes  reversal-learning / task switching

25. Clinical Anatomy 500 • Which pattern of olfactory loss (left, right, bilateral) would be caused by lesions at the following sites? • Left olfactory mucosa • Left olfactory bulb • Left olfactory tract • Left primary olfactory cortex • Left thalamus

26. Clinical Anatomy 500

27. Clinical Anatomy 500 • Left olfactory mucosa  left sided loss • Left olfactory bulb  left sided loss • Left olfactory tract  left sided loss • Left primary olfactory cortex  no loss • Left thalamus  no loss

29. Book Anatomy

30. Book Anatomy 100 • What are the two main pathways connecting the hippocampal formation and the entorhinal cortex?

31. Book Anatomy 100

32. Perforant pathway Entorhinal cortex  Dentate gyrus  Hippocampus (CA1&3)  Subiculum  Entorhinal cortex 2)Alvear pathway Entorhinal cortex    Hippocampus (CA1&3)  Subiculum  Entorhinal cortex Book Anatomy 100

34. Book Anatomy 200 • What are the 3 main targets of axons travelling forward in the fornix? • Where do axons travelling backward in the fornix originate from?

35. Book Anatomy 200

36. Book Anatomy 200 • Axons travelling forward in the fornix: • 1) subiculum  postcommissural fornix  mammillary nuclei • 2) subiculum & hippocampus  precommissural fornix  lateral septal nucleus • 3) Fornix  anterior thalamic nucleus • Axons travelling backward in the fornix: • Medial septal nucleus hippocampal formation

38. Book Anatomy 300 • True or False: HM’s bilateral medial temporal lobectomy was performed by Dr. Wilder Penfield at the Montreal Neurological Institute.

39. Book Anatomy 300 • False. It was done by Dr. William Scoville in Hartford, Connecticut

41. Pathway Uncinate fasciculus Stria terminalis and amygdalofugal pathway Medial forebrain bundle Structure Orbital frontal cortex Hypothalamus and the septal region Brainstem Book Anatomy 400 Which pathway connects the following structure to the amygdala?

42. Book Anatomy 400

44. Book Anatomy 500 • Name all the structures involved in the Papez circuit • BONUS: Describe the connections between these structures in the Papez circuit…

45. Book Anatomy 500 http://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Papez_Circuit.jpg/400px-Papez_Circuit.jpg

47. Syndromes

48. Syndromes 100 • Which syndrome is caused by bilateral lesions of the amygdala and adjacent temporal structures? • What are its main characteristics?

49. Syndromes 100 Kluver-Bucy syndrome: Placid, tame, non-aggressive behaviour Hyperorality Hypersexuality Visual agnosia