The document discusses the basal ganglia, which are a group of subcortical gray matter structures in the cerebrum that include the corpus striatum, amygdala, and claustrum. It describes the main components and connections of the basal ganglia, including the striatum, globus pallidus, substantia nigra, and subthalamic nucleus. The basal ganglia are involved in coordinating movement through connections with the cerebral cortex, thalamus, and brainstem. Disorders like Parkinson's disease can result from basal ganglia dysfunction and cause issues like tremors, rigidity, and bradykinesia.

1. BASAL GANGLIA Dr. Israa M. Sulaiman Department of Anatomy IMS/MSU

2. Define basal ganglia and describe the parts Describe the main connections and functions Describe the function and the disorders of basal ganglia such as Parkinsonism and tremors OBJECTIVES

3. Basal ganglia The basal ganglia is a collection of gray matter in the cerebrum including the corpus striatum, amygdala and claustrum. Has important connections with other regions of the brain, particularly: thalamus, subthalamic nuclei, red nucleus and substantia nigra Important in coordinating movement.

4. Traditional Concepts of Basal Ganglia Corpus Striatum Caudate Nucleus Lenticular Nucleus Putamen Globus Pallidus Paleostriatum Pallidum Corpus Amygdaloideum Archistriatum Neostriatum Striatum Basal Ganglia

5. 1. Putamen 2. Tail of caudate nucleus 3. Caudatolenticular gray bridge 4. Amygdaloid body 5. thalamus Lateral surface of basal ganglia

6. 1. head of caudate nucelus 2. body of caudate nucelus 3. caudatolenticular gray bridge 4. putamen 5. tail of caudate nucleus 6. external segment of globus pallidus 7. internal segment of globus pallidus 8. amygdaloid body 9. nucleus accumbens septi Medial surface of basal ganglia

7. Components of Basal Ganglia Corpus Striatum Striatum ----- Caudate Nucleus & Putamen Pallidum ----- Globus Pallidus (GP) Substantia Nigra Pars Compacta (SNc) Pars Reticulata (SNr) Subthalamic Nucleus (STN) Ventral Striatum and Ventral Pallidum Nucleus Accumbens Septi Non cholinergic portion of Substantia Innominata Basal Ganglia Components

8. STRIATUM Caudate Nucleus Head, (Corpus), Tail caudatolenticular gray bridge Putamen Ventral Striatum : Nucleus Accumbens (Septi) Basal Ganglia Components

9. BASAL GANGLIA BASAL GANGLIA CORPUS STRIATUM AMYGDALA NEOSTRIATUM CAUDATE NUCLEUS PALEOSTRIATUM PUTAMEN GLOBUS PALLIDUS LENTIFORM NUCLEUS CLAUSTRUM

10. TERMINOLOGIES Neurological structure Basal nuclei Corpus striatum Caudate nucleus + lentiform nucleus Amygdala Amygdaloid nucleus Claustrum Claustrum Neostriatum Caudate nucleus + putamen Paleostriatum Globus pallidus Caudate nucleus Caudate nucleus Lentiform nucleus Globus pallidus + putamen

11. Anterior horn Inferior horn Posterior horn Amygdaloid nucleus Basal ganglia

12. Basal Ganglia Components Striosome and Matrix compartment AchE

13. Putamen Globus pallidus external segment internal segment Subthalamic Nucleus Substantia nigra Internal capsule Components of Basal Ganglia

14. habenular nucleus tectum (superior colliculus) PPN (pedunculopontine nucleus) amygdaloid body raphe Cerebral Cortex STN Pallidum SNr STRIATUM Connections of the Basal Ganglia SNc Thalamus

15. Basal Ganglia (Prefronatal Complex Loop) Connections Prefrontal Association Cortex Primary Motor Area (M I) THALAMUS (VLm, VAmc, MD) STRIATUM (Caudate Nucleus) SNr (Substantia Nigra, pars reticulata) pyramidal tract LMN

16. Basal Ganglia (Limbic Loop) Connections Orbitofrontal Cortex Anterior Cingulate Gyrus Hippocampal Formation THALAMUS (VAmc, MD) Ventral Striatum Caudate Nucleus Ventral Pallidum GPi, SNr

17. Basal Ganglia (Oculomotor Loop) Connections Frontal Eye Field (area 8) Primary Motor Area (M I) THALAMUS (VLm, VAmc, MD) STRIATUM (Caudate Nucleus) SNr (Substantia Nigra, pars reticulata) pyramidal tract LMN Tectum

18. Basal Ganglia (SNc and CM-PF nuclear complex) Connections Pallidum Striatum THALAMUS (CM-PF) Pallidum Striatum SNc

19. Basal Ganglia (Brain Stem Efferents) Phylogeny GPi SNr Tectum (superior colliculus) SpL nDCP DIP (thalamus) Neostriatum Intermediale (motor cortex) aves (birds) GPi SNr Tectum (superior colliculus) nPC VA-VL complex (thalamus) motor cortex mammals

20. Basal Ganglia (STN) Connections SNr GPi STN GPe subthalamic fasciculus Output Portion of Basal Ganglia Cerebral Coretx Thalamus (CM-PF) PPN Subthalamic Nucleus

22. Caudate nucleus Putamen Globus pallidus Claustrum Lentiform nucleus Insula Basal ganglia HORIZONTAL SECTION ANTERIOR POSTERIOR

23. Thalamus Amygdala SUPERIOR INFERIOR CORONAL SECTION Basal ganglia Caudate nucleus Claustrum Lentiform nucleus

24. Thalamus Substantia nigra Subthalamic nucleus SUPERIOR INFERIOR CORONAL SECTION Basal ganglia Caudate nucleus Tail of Caudate nucleus

25. Thalamus Substantia nigra Red nucleus SUPERIOR INFERIOR CORONAL SECTION Basal ganglia

26. corpus striatum Caudate nucleus Putamen Globus pallidus lentiform nucleus Putamen Globus pallidus neostriatum Caudate nucleus Putamen paleostriatum Globus pallidus Caudate n Thalamus POST ANT Horizontal section Globus pallidus Putamen Lateral ventricle-Ant horn Third ventricle Lateral ventricle-Post horn

27. Caudate nucleus Putamen Globus pallidus Claustrum Amygdala (part of limbic system) Basal ganglia Caudate n Thalamus POST ANT Horizontal section Globus pallidus Putamen Lateral ventricle-Ant horn Third ventricle Lateral ventricle-Post horn

28. C-shaped Head, body,tail Large head,tapering curved tail Head-frontal lobe Tail-occipital lobe End of tail-temporal lobe -terminates in amygdaloid nucleus (roof of inf horn of lateral ventricle) Caudate nucleus Lentiform Caudate nucleus thalamus Caudate Amygdaloid Putamen Globus pallidus

29. Caudate nucleus

30. Lentiform nucleus Lentiform thalamus Caudate Amygdaloid Putamen Globus pallidus Putamen – lateral medullary lamina – Globus Pallidus Lat GP – medial medullary lamina – Med GP

31. Lentiform nucleus Putamen Globus pallidus Lateral medullary lamina Medial medullary lamina Lat GP Med GP

32. Lentiform nucleus Wedge-shaped Internal capsule External capsule Extreme capsule Claustrum Lateral and medial medullary lamina Caudate n Thalamus POST ANT Horizontal section Globus pallidus Putamen Lateral ventricle-Ant horn Third ventricle Lateral ventricle-Post horn

33. Amygdaloid nucleus Lentiform thalamus Caudate Amygdaloid Putamen Globus pallidus Temporal lobe - Roof of inf horn of lateral ventricle

34. Caudate n Thalamus Globus pallidus Putamen Subthalamic nuclei Substantia nigra Substantia nigra Subthalamic nuclei Coronal section

35. Connections Caudate nucleus Putamen Globus pallidus – output leaves receive input

36. Connections of striatum Caudate nucleus & putamen – input Receive afferent - cerebral cortex, intralaminar thalamic nuclei, subs nigra Efferent – globus pallidus, subs nigra Connections of globus pallidus 2 segments – med & lat Med & subs nigra – output Receive afferent – striatum, subthalamic nucleus Efferent Lat – subthalamic N Med – thalamus (VA,VL,CM) – motor areas

37. Connections CN/ i/laminar thal

38. Connections of basal ganglia Afferent Corticostriate Thalamostriate Nigrostriate Brainstem striatal fibres Striatopallidal Subthalamic nucleus Mostly end in neostriatum except subthalamic N end in paleostriatum Efferent Striatopallidal Striatonigral Pallidofugal fibres Ansa lenticularis Fasciculus lenticularis Pallidotegmental Pallidosubthalamic

39. Corticostriate-Glutamate thalamostriate Nigrostriate-dopa Striatopallidal-GABA Brainstem striatal-serotonin Striatopallidal-GABA Striatonigral-GABA,Ach Ansa lenticularis Fasciculus lenticularis pallidotegmental pallidosubthalamic Caudate n Thalamus Globus pallidus Putamen Subthalamic nuclei Substantia nigra Subthalamus-pallidal Connections of basal ganglia Afferent fibres Efferent fibres Pallidofugal fibres

40. Connections of corpus striatum Afferent Cerebral cortex-Corticostriate Thalamic nuclei-Thalamostriate Substantia nigra-Nigrostriate Brainstem striatal fibres Efferent Globus pallidus-Striatopallidal Substantia nigra-Striatonigral

41. Connections of striatum Caudate nucleus & putamen – input Receive afferent - cerebral cortex, intralaminar thalamic nulcei, subs nigra Efferent – globus pallidus, subs nigra

42. premotor 1 o sensory 1 2 4 Brainstem supplementary motor 3

43. Connections of globus pallidus Afferent Striatum-striatopallidal Subthalamic nucleus Subthalamonigral- Efferent Thalamic nuclei-Ansa lenticularis Subthalamus-Fasciculus lenticularis Tegmental of midbrain-Pallidotegmental Subthalamic nuclei-Pallidosubthalamic

44. Connections of globus pallidus 2 segments – med & lat Med GP & subs nigra – output Receive afferent – striatum, subthalamic nucleus Efferent Lat GP – subthalamic N Med GP – thalamus (VA,VL,CM) – motor areas

45. 1 2 Ansa lenticularis Fasc lenticularis Pallidosubthalamic Pallidotegmental

46. Function Cerebral cortex, basal ganglia, cerebellum and thalamus motor activity muscle tone organisation of movement What type ? -cerebral cortex How to perform? -basal ganglia+cerebellum Assist in regulation-thalamus

47. Part of extra-pyramidal motor system Facilitate behaviour & movement – required and appropriate Inhibit unwanted & inappropriate Function

48. “ Brake hypothesis” The deficits tend to fall into one of two categories: the presence of extraneous unwanted movements OR an absence or difficulty with intended movements.

49. The balance between the cerebellum and the basal ganglia allows smooth, coordinated movement, and a disturbance in either system will show up as movement disorders. Function

50. Destruction of primary motor – Unable to perform fine discrete movement But still able to perform crude movement Destruction of corpus striatum – Total paralysis

51. Cerebral cortex Corticospinal Corticobulbar Corticostriatal Direct Indirect Striatonigral Striatopallidal inhibitory Disinhibit neurone thalamus Facilitate movement Subthalamic N Med pallidal inhibitory inhibitory Lat pallidal Activate neurone Inhibit unwanted movement excitatory

52. Disease of basal ganglia Change in muscle tone Abnormal involuntary movement Parkinsonism Effect on the opposite side Degeneration of dopamine-producing cells in substantia nigra-depletion of dopamine in striatum Resting tremor Rigidity – simultaneous contraction of flexors and extensors Bradykinesia = Slowness of movement – brake cannot be released No paralysis, sensory loss, ataxia

53. Cerebral cortex Corticospinal Corticobulbar Corticostriatal Direct Indirect Striatonigral Striatopallidal inhibitory Disinhibit neurone thalamus Facilitate movement Subthalamic N Med pallidal inhibitory inhibitory Lat pallidal Activate neurone Inhibit unwanted movement excitatory

54. Corticostriate-Glutamate thalamostriate Nigrostriate-dopa Striatopallidal-GABA Brainstem striatal-serotonin Striatopallidal-GABA Striatonigral-GABA,Ach Ansa lenticularis Fasciculus lenticularis pallidotegmental pallidotsubthalamic Caudate n Thalamus Globus pallidus Putamen Subthalamic nuclei Substantia nigra Subthalamus-pallidal Connections of basal ganglia Afferent fibres Efferent fibres Pallidofugal fibres

55. Huntington’s disease – hereditary disease of unwanted movements. It results from degeneration of the caudate and putamen, and produces continuous dance-like movements of the face and limbs -choreoathetosis Hemiballism - flailing movements of one arm and leg (one-sided), which is caused by damage (i.e., stroke) of the subthalamic nucleus. Disease of basal ganglia

56. Caudate n Thalamus Globus pallidus Putamen Subthalamic nuclei Substantia nigra Afferent fibres Efferent fibres

57. Caudate n Thalamus Globus pallidus Putamen Subthalamic nuclei Substantia nigra Afferent fibres Efferent fibres

58. Connections of basal ganglia-afferent fibres A-Brainstem striatal fibres B-thalamostriate C-corticostriate D-subthalamic E-nigrostriate Match the connections - EXCERCISE

59. Connections of basal ganglia-efferent fibres A-pallidosubthalamic B-striatopallidal C-ansa lenticularis D-striatonigral Match the connections - EXCERCISE

60. THANK YOU