Basal ganglia

Authors
Affiliations

Nathaniel Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

Principal nuclei

There are 5 principal basal ganglia nuclei.

  1. Caudate Nucleus
  2. Putamen
  3. Globus Pallidus
  4. Subthalamic Nucleus
  5. Substantia Nigra (in midbrain)

Lentiform nucleus: Putamen + Globus Pallidus striatum: Caudate Nucleus + Putamen

Types of Nuclei

3 type of nuclei:

  1. Input nuclei
  2. Output nuclei
  3. Intrinsic nuclei

Input Nuclei

  • Receives info from cortex, thalamus
  • Examples: striatum: Caudate Nucleus & Putamen

Output Nuclei

  • Sends BG info to the Thalamus
  • E.G.: Globus Pallidus internus & Substantia Nigra (pars reticulata)

Intrinsic Nuclei

  • Connect input & Output nuclei
  • E.G.: Globus Pallidus externus, ST nucleus, Substantia Nigra (Pars compacta)

Function

  • Through extensive motor & sensory cortical connections > Influences executive motor function (motor hierarchy)
    • BG decide whether or not to execute movement
    • Streamlines the movement
  • Organize all cortical activity into one behavioral output

Practical function:

  • Learning & Cognition:
  • Integration of motor output
  • Regulates emotional aspects of Behavior

Pathway

  1. Direct
  2. Indirect pathway
  3. Substantonigral pathway
  • Result = Measured and coordinated motor output

Direct Pathway

  • Direct = facilitates goal-oriented movement

Striatum disinhibits the thalamus which results in more excitation of the

Indirect Pathway

  • Indirect = Suppress all competing movement

Dopamine from the Sn Pars Compacta functions to inhibit the striatum. Thus dopamine causes disinhibition of the GPe and therefore this causes disinhibition of the thalamus.

Dysfunction

DPT 836

Lesions result in difficulty initiating, continuing, or stopping movement

Pathologies

Citation

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