Basal Ganglia Flashcards
Basal Ganglia
Basal ganglia are = ?
Basal ganglia are group of interconnected subcortical nuclei which lie deep within the white matter of the cerebral hemisphere.
Basal Ganglia
Caudate: located in = ?
Anatomical Orientation of Basal Ganglia
- Caudate: located in the cerebrum
Basal Ganglia
Putamen: located in = ?
Anatomical Orientation of Basal Ganglia
- Putamen: located in the cerebrum
Basal Ganglia
Caudate + Putamen = ?
Anatomical Orientation of Basal Ganglia
- Together they make = Striatum
- Caudate: located in the cerebrum
- Putamen: located in the cerebrum
Basal Ganglia
Globus pallidus: located in = ?
Anatomical Orientation of Basal Ganglia
Globus pallidus: located in the cerebrum
Basal Ganglia
Putamen + Globus pallidus = ?
Anatomical Orientation of Basal Ganglia
- Together they make Lentiform nucleus
- Putamen: located in the cerebrum
- Globus pallidus: located in the cerebrum
Basal Ganglia
Subthalamic nucleus: located = ?
Anatomical Orientation of Basal Ganglia
Subthalamic nucleus: located inferior to thalamus
Basal Ganglia
Substantia nigra: located within = ?
Substantia nigra: located within the midbrain
Basal Ganglia
Caudate and putamen (striatum), and subthalamic nuclei= _ ? _ nuclei
Input nuclei = Caudate and putamen (striatum), subthalamic nuclei.
Basal Ganglia
Substantia nigra pars reticulata and globus pallidus internus (GPi) = _ ? _ nuclei
Output nuclei = Substantia nigra pars reticulata and globus pallidus internus (GPi)
Basal Ganglia
Functions of Basal Ganglia = ?
Motor functions
- Initiation of movement
- Suppression of unwanted movements
Non- motor functions
- Decision making, judgment, prioritizing information, emotional processing and responses, learning, eye movements, selecting desired behavior, preventing undesired behavior
Basal Ganglia
Five cortico-basal ganglia-thalamic loops are ?
Basal Ganglia Circuitry
Three cortico-basal ganglia-thalamic circuits: non motor functions
1. Goal directed behavior
2. Social behavior loop
3. Emotion loop
- Motor loop (direct pathway and indirect pathway)
- Oculomotor loop
All loops: cortex - basal ganglia - thalamus - cortex
Basal Ganglia
What loop?
Goal Directed Behavior Loop
- Goal directed behavior- evaluating information for making decisions, planning and choosing actions
- Head of caudate = Part of decision making loop
Case study: caudate head infarction: goal directed behavior (decision making) deficits including, inattention, distractibility, disorientation, poor concentration and short term memory. No movement disorder
Basal Ganglia
What loop?
Social Behavior Loop
- Head of caudate is part of loop that recognizes social cues, regulates self control, and parses out relevant from irrelevant information
- Case of isolated bilateral caudate head lesion: impulsive, prone to frustration over minor issues, violent, indifferent, hypersexual, shop lifting. No motor abnormalities present.
Basal Ganglia
What loop?
Emotion Loop
- Loop is responsible for integrating emotions and facial expression (partly responsible for mask like face), seeking rewards, predictions when outcome is unknown, addictions
- Basal ganglia stroke- depression, emotional blunting
Basal Ganglia
Describe flow of goal directed behavior loop
Goal Directed Behavior Loop
- lateral prefrontal cortex
- head of caudate = part of decision making loop
- globus pallidus internus
- ventral anterior - thalamus
- back to prefrontal cortex
Basal Ganglia
Describe flow of social behavior loop
Social Behavior Loop
- Ventral prefrontal cortex
- Head of caudate = part of loop that recognizes social cues, regulates self control, and parses out relevant from irrelevant information
- Substantia nigra reticularis
- Medial dorsal - Thalamus
- back to ventral prefrontal cortex
Basal Ganglia
Describe flow of emotion loop
Emotion Loop
- Medial prefrontal cortex
- Putamen (VS)
- Globus pallidus externus (VP)
- Medial dorsal - thalamus
- back to medial prefrontal cortex
Basal Ganglia
Goal directed behavior loop:
- Cerebral cortex = ?
- Basal ganglia = ?
- Thalamic nuclei = ?
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Basal Ganglia
Social behavior loop:
- Cerebral cortex = ?
- Basal ganglia = ?
- Thalamic nuclei = ?
Basal Ganglia
Emotion loop:
- Cerebral cortex = ?
- Basal ganglia = ?
- Thalamic nuclei = ?
Basal Ganglia
Describe the Oculomotor Loop
- Body of the caudate is part of an oculomotor loop.
- Makes decision about spatial attention and eye movements; specifically determining weather to use fast eye movements to direct attention towards an object.
- In basal ganglia pathology: demonstrate impaired saccadic eye movements
Basal Ganglia
Motor loops are important for ?
- Important for planning and programming of movement by selecting and inhibiting specific motor strategies, initiation of movement
Basal Ganglia
Describe Motor Loop: Direct Pathway
Motor Loop Direct Pathway:
- Consists of signals transmitted from the cortex to putamen/ substantia nigra reticulata to Globus pallidus, to ventrolateral (VL) nucleus of the thalamus, and back to cortex.
- Serves to activate the motor and premotor cortex and assists in the initiation of voluntary movement.
- Go pathway
Basal Ganglia
Describe Motor Loop: Indirect Pathway
Motor Loop Indirect:
- Loopthrough the BG involves the GPe, subthalamic nucleus, GPi, substantia nigra reticuclata.
- Serves to decrease thalamocortical activation
- Suppresses unwanted movements
- No-Go pathway
Basal Ganglia
What loops?
Motor Loop (Darker)
- Cortex = Motor and premotor cortex
- Basal Ganglia = Putament, globus pallidus
- Thalamic Nuclei = Ventral lateral
Occulomotor Loop
- Cortex = Frontal and supplementary eye fields
- Basal Ganglia = Caudate body and substantia nigra reticularis
- Thalamic Nuclei = Ventral anterior
