basal ganglia nucleus parts function of the basal ganglia
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Basal ganglia/nucleus Parts Function of the basal ganglia Direct = - PowerPoint PPT Presentation

Basal ganglia/nucleus Parts Function of the basal ganglia Direct = Dark grey Red Blue Light grey Indirect = Dark grey Green Blue Light grey Text Fig. 26-9 Medium spiny neuron projections Neurons of the basal ganglia


  1. Basal ganglia/nucleus

  2. Parts

  3. Function of the basal ganglia

  4. Direct = Dark grey – Red – Blue – Light grey Indirect = Dark grey – Green – Blue – Light grey Text Fig. 26-9

  5. Medium spiny neuron projections

  6. Neurons of the basal ganglia

  7. Connections and circuits

  8. Functional loops

  9. Motor Loop

  10. Text Fig. 26-10A,B

  11. Text Fig. 26-10C,D

  12. Text Fig. 26-10C,D

  13. Modulators (associated nuclei)

  14. Modulators (associated nuclei) - Subthalamic Nucleus ????? - Nigral Complex (Dopamine) - Pedunculo-pontine nucleus (Acetylcholine)

  15. Modulators (associated nuclei) - Subthalamic Nucleus ????? - Nigral Complex (Dopamine) - Pedunculo-pontine nucleus (Acetylcholine)

  16. Nigral modulation glu R EPSP DA Direct transmission

  17. Direct transmission vs. modulation glu DA Almost No direct effect of DA

  18. Direct transmission vs. modulation Striatal medium spiny neuron glu enhanced or diminished response R D1-Rs in the direct pathway: DA Excitatory effect on the pathway, hence Increase cortical activity Modulation

  19. Direct transmission vs. modulation Striatal medium spiny neuron glu enhanced or diminished response R D2-Rs in the indirect pathway: DA Inhibitory effect on the pathway, hence Increase cortical activity Modulation

  20. Direct and Indirect Pathways (Including the Substantia Nigra Text Fig. 26-14A,B

  21. Modulators (associated nuclei) - Subthalamic Nucleus ????? - Nigral Complex (Dopamine) - Pedunculo-pontine nucleus (Acetylcholine)

  22. Direct transmission vs. modulation Striatal medium spiny neuron glu enhanced or diminished response R M4-Rs in the direct pathway: Ach 1) Inhibitory, hence decrease cortical activation Modulation

  23. Direct transmission vs. modulation Striatal medium spiny neuron glu enhanced or diminished response R M1-Rs in the indirect pathway: Ach excitatory, hence Decrease cortical activity Modulation

  24. Motor behavior is determined by the balance between direct/indirect striatal outputs Hypokinetic disorders • insufficient direct pathway output • excess indirect pathway output Hyperkinetic disorders • excess direct pathway output • insufficient indirect pathway output

  25. Parkinson ’ s disease Michael J. Fox Muhammad Ali Striatum Pathophysiology Primary: loss of nigrostriatal DA projection SNc

  26. Parkinson’s disease Treatment Dopamine Acetylcholine Deep brain stimulation subthalamic nucleus (STN)/ globus pallidus interna (GPi) high frequency stimulation inactivates the STN or GPi.

  27. Motor behavior is determined by the balance between direct/indirect striatal outputs Hypokinetic disorders • insufficient direct pathway output • excess indirect pathway output Hyperkinetic disorders • excess direct pathway output • insufficient indirect pathway output

  28. Hyperkinetic symptoms Involuntary (unwanted) movements • Chorea • Ballismus • Dystonia • Athetosis

  29. Hyperkinetic disorders: choreatic syndromes 1. Huntington’s Chorea 2. Sydenham Chorea 3. Dystonia 4. Tardive dyskinesia 5. DOPA-induced dyskinesia 6. Hemiballismus 7. Tourette’s syndrome

  30. Huntington ’ s disease Pathophysiology • Atrophy of striatum • Loss of striatal neurons • Neuropathological sequence • start , rostral and medial then caudal and lateral

  31. Huntington’s disease Choreatic gait Symptoms Early motor signs  chorea (brief, involuntary Dystonic movements movements)  later have dystonia episodes

  32. Hyperkinetic disorders: 1. Huntington’s Chorea 2. Sydenham Chorea 3. Dystonia 4. Tardive dyskinesia 5. DOPA-induced dyskinesia 6. Hemiballismus 7. Tourette’s syndrome

  33. Hyperkinetic disorders: choreatic syndromes Cervical dystonia Huntington’s disease Dystonia Tardive dyskinesia After botulinum toxin DOPA-induced dyskinesia Hemiballismus Tourette’s syndrome

  34. Hyperkinetic disorders: choreatic syndromes Huntington ’ s disease Dystonia Tardive dyskinesia After treatment with the D2-R blocker sulpiride DOPA-induced dyskinesia Hemiballismus – unilateral STN stroke Tourette ’ s syndrome

  35. Hyperkinetic disorders: 1. Huntington ’ s Chorea 2. Sydenham Chorea 3. Dystonia 4. Tardive dyskinesia 5. DOPA-induced dyskinesia 6. Hemiballismus 7. Tourette ’ s syndrome

  36. Hyperkinetic disorders: 1. Huntington’s Chorea 2. Sydenham Chorea 3. Dystonia 4. Tardive dyskinesia 5. LDOPA-induced dyskinesia 6. Hemiballismus 7. Tourette’s syndrome

  37. Hyperkinetic disorders: 1. Huntington ’ s Chorea 2. Sydenham Chorea 3. Dystonia 4. Tardive dyskinesia 5. LDOPA-induced dyskinesia 6. Hemiballismus 7. Tourette ’ s syndrome

  38. Hyperkinetic disorders: Tourette’s syndrome https://www.youtube.com/watch?v=e8HtTb0Vk_o https://www.youtube.com/watch?v=jYRa-fpNonY

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