Podcast
Questions and Answers
What is the origin of the motor loop through the basal ganglia?
What is the origin of the motor loop through the basal ganglia?
What is the role of the direct pathway through the basal ganglia?
What is the role of the direct pathway through the basal ganglia?
What effect does cortical activation have on putamen neurons?
What effect does cortical activation have on putamen neurons?
What is the role of neurons in the internal segment of the globus pallidus at rest?
What is the role of neurons in the internal segment of the globus pallidus at rest?
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What happens when putamen neurons inhibit GPi neurons?
What happens when putamen neurons inhibit GPi neurons?
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What is the effect of VLo activity on the SMA?
What is the effect of VLo activity on the SMA?
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What is the function of the circuit involving VLo and SMA?
What is the function of the circuit involving VLo and SMA?
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What tends to antagonize the motor functions of the direct pathway?
What tends to antagonize the motor functions of the direct pathway?
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Which nucleus is excited by axons from the cortex and its projections excite the neurons of the GPi?
Which nucleus is excited by axons from the cortex and its projections excite the neurons of the GPi?
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What does the activation of the indirect pathway by the cortex tend to do to the thalamus?
What does the activation of the indirect pathway by the cortex tend to do to the thalamus?
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What is the role of the direct pathway in selecting motor actions?
What is the role of the direct pathway in selecting motor actions?
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Which structure is inhibited by cells of the GPe and then inhibits cells of both the GPi and subthalamic nucleus?
Which structure is inhibited by cells of the GPe and then inhibits cells of both the GPi and subthalamic nucleus?
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What is the role of the indirect pathway in relation to competing motor programs?
What is the role of the indirect pathway in relation to competing motor programs?
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Which pathway tends to facilitate the thalamus and information passing through it?
Which pathway tends to facilitate the thalamus and information passing through it?
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What is the most unique feature of the indirect pathway?
What is the most unique feature of the indirect pathway?
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What tends to antagonize the motor functions of the direct pathway?
What tends to antagonize the motor functions of the direct pathway?
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Which nucleus is excited by axons from the cortex and its projections excite the neurons of the GPi?
Which nucleus is excited by axons from the cortex and its projections excite the neurons of the GPi?
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What tends to inhibit the thalamus when activated by the cortex?
What tends to inhibit the thalamus when activated by the cortex?
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Which pathway may help to select certain motor actions?
Which pathway may help to select certain motor actions?
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What is inhibited by cells of the GPe, which then inhibit cells of both the GPi and subthalamic nucleus?
What is inhibited by cells of the GPe, which then inhibit cells of both the GPi and subthalamic nucleus?
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Which neurons does the subthalamic nucleus excite?
Which neurons does the subthalamic nucleus excite?
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What does the activation of the direct pathway by the cortex tend to facilitate?
What does the activation of the direct pathway by the cortex tend to facilitate?
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What does the indirect pathway simultaneously suppress?
What does the indirect pathway simultaneously suppress?
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What is the origin of the motor loop through the basal ganglia?
What is the origin of the motor loop through the basal ganglia?
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In the direct pathway through the basal ganglia, synapses from cortical cells excite cells in the ________.
In the direct pathway through the basal ganglia, synapses from cortical cells excite cells in the ________.
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What is the role of the direct pathway through the basal ganglia?
What is the role of the direct pathway through the basal ganglia?
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What is the effect of cortical activation on putamen neurons?
What is the effect of cortical activation on putamen neurons?
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Neurons in the internal segment of the globus pallidus tonically inhibit which structure?
Neurons in the internal segment of the globus pallidus tonically inhibit which structure?
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What is the role of the internal segment of the globus pallidus in the motor loop?
What is the role of the internal segment of the globus pallidus in the motor loop?
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What is the function of the positive-feedback loop in the circuit?
What is the function of the positive-feedback loop in the circuit?
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Study Notes
Origin of the Motor Loop
- The motor loop originates from the cerebral cortex, specifically areas involved in motor control.
Role of the Direct Pathway
- The direct pathway facilitates selected motor actions by providing excitatory inputs to the motor thalamus, increasing motor activity.
Effect of Cortical Activation on Putamen Neurons
- Cortical activation leads to excitation of putamen neurons, enhancing their activity in the motor loop.
Neurons in the Internal Segment of the Globus Pallidus at Rest
- These neurons tonically inhibit the thalamus, preventing unwanted motor activity when at rest.
Inhibition of GPi Neurons by Putamen Neurons
- When putamen neurons inhibit GPi neurons, it reduces inhibitory output to the thalamus, allowing increased movement.
Effect of VLo Activity on the Supplementary Motor Area (SMA)
- VLo activity enhances the excitability of the SMA, promoting motor planning and execution.
Function of Circuit Involving VLo and SMA
- This circuit plays a crucial role in coordinating and planning motor actions, linking higher-order cognitive functions with motor control.
Antagonism of the Direct Pathway
- The indirect pathway tends to antagonize motor functions of the direct pathway, competing for the same motor outputs.
Nucleus Excited by Cortical Axons
- The subthalamic nucleus is excited by cortical axons, which project to and excite GPi neurons, influencing movement.
Activation of the Indirect Pathway by Cortex
- Activation of the indirect pathway leads to increased inhibition of the thalamus, thereby reducing motor output.
Role of Direct Pathway in Action Selection
- It assists in the selection of desired motor actions, helping to streamline movement execution.
Structure Inhibited by GPe
- The Globus Pallidus externus (GPe) inhibits neurons in both the GPi and the subthalamic nucleus, modulating their activity.
Role of Indirect Pathway for Competing Motor Programs
- It functions to suppress competing motor programs that may interfere with the execution of desired movements.
Pathway that Facilitates Thalamus
- The direct pathway through the basal ganglia facilitates the thalamus, promoting informational flow relevant to movement.
Unique Feature of the Indirect Pathway
- The indirect pathway's unique feature is simultaneous suppression of unwanted motor activities while enhancing the inhibition of the thalamus.
Antagonism of Direct Pathway by Other Functions
- The indirect pathway's activity antagonizes the facilitation of motor functions provided by the direct pathway.
Neurons Excited by Subthalamic Nucleus
- The subthalamic nucleus excites neurons in the GPi, contributing to movement regulation.
Direct Pathway Activation and Facilitation
- Activation of the direct pathway by cortical signals tends to facilitate voluntary movements.
Indirect Pathway Suppression
- The indirect pathway simultaneously suppresses motor activities that are not selected for execution.
Positive-Feedback Loop Function
- The positive-feedback loop within the circuit enhances specific motor outputs and reinforces selected motor actions, contributing to efficient motor control.
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Description
Test your knowledge of the direct and indirect pathways through the basal ganglia with this quiz. Explore the motor loop originating from the cortex and the excitatory and inhibitory connections within the basal ganglia.
