Basal Ganglia

Objectives Anatomy and Blood supply: Draw or describe the Motor Loop Striatum – Caudate and Putamen Lentiform – Putamen and Globus Pallidus (internus and externus) Subthalamic nuclei Substantia Nigra (pars compacta, pars reticulata) Pedunculopontine Nucleus Draw or describe the Motor Loop Describe the pathologies of Parkinson’s and Huntington’s Diseases

Caudate nucleus Inferior and lateral to superior horn of lateral ventricles Superior and lateral to inferior horn of lateral ventricles

Caudate nucleus Part of neostriatum Head is connected to putamen Tail is connected to amygdala Lenticulostriate branches of MCA

putamen Part of neostriatum and lentiform nucleus Lenticulostriate branches of MCA

Globus pallidus (Pallidum) Paleostriatum Internus and externus Lenticulostriate branches of MCA

Other small structures Subthalamus (STN) Substantia Nigra 2 parts: SNr SNc Pedunculopontine Nucleus (PPN)

Motor control Lateral pathways Ventromedial pathways Lateral = voluntary conscious control Ventromedial = postural muscles and balance

Motor loop Basal Ganglia Loop: Direct pathway Indirect pathway Increased motor activity Indirect pathway Decreased motor activity Thalamus – VL nucleus specifically

Draw it Motor Cortex Thalamus Striatum SNr GPi GPe SNc STN

simplified & Caudate GPe & SNr

Parkinson’s https://www.youtube.com/watch?v=hu4eTijdIv0 https://www.youtube.com/watch?v=dGeMX_h67mI

Parkinson’s Disease Compare and contrast this depiction of Parkinson’s with the previous normal diagram. What’s the source of the problem? How is each pathway affected? What are the symptoms that result? HINT: the size of the text and thickness of arrows show relative amounts of activation GPe

Huntington’s https://www.youtube.com/watch?v=JzAPh2v-SCQ

Huntington’s disease Compare and contrast this depiction of Huntington’s with the 2 diagrams. What’s the source of the problem? How is each pathway affected? What are the symptoms that result? GPe

Draw and explain to study Draw the Basal Ganglia motor loop Label each pathway within the loop and whether it is excitatory or inhibitory Explain to a partner why the direct loop increases movement and why the indirect loop decreases movement

Conclusion Assignment 5 due Monday!! Read L-E ch. 11 part 2 to reinforce motor loop for Quiz 3 and Final Exam