Accepted
at 3:58 a.m. Jan, 10, 2026
by
mohsenz22
Author:
jarvisdover78
Type of change:
Content error
Rationale for change
This is physiologically wrong. In a functional nigrostriatal path, D2 receptors when activated work to INHIBIT the indirect pathway, thus causing MORE movement. In Parkinsons, there is REDUCED dopamine, thus an inability to INHIBIT the indirect path via D2 receptors, thus LESS movement.
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Direct and indirect pathways as seen in Parkinson disease
Image credit: Photo by Phoebe I
- Note: This card was updated to correct a content error on 10 Jan 2026. Please review accordingly.
- In Parkinson’s disease, loss of dopaminergic neurons in the substantia nigra pars compacta leads to increased inhibition of the thalamus, producing hypokinetic symptoms
- Direct pathway: Normally, D1 receptor–expressing striatal neurons inhibit the GPi, disinhibiting the thalamus and facilitating movement. Loss of dopamine → reduced D1 stimulation → less inhibition of GPi → thalamus remains inhibited → decreased movement
- Indirect pathway: Normally, D2 receptor–expressing striatal neurons are inhibited by dopamine, keeping the indirect pathway in check and allowing movement. Loss of dopamine → D2 neurons disinhibited → increased indirect pathway activity → GPi becomes overactive → thalamus is further inhibited → decreased movement
Direct and indirect pathways as seen in Parkinson disease
Image credit: Photo by Phoebe I
Extra (Synced)
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Personal Notes
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Missed Questions
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eTG Complete
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Talley & O'Connor
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Additional Resources
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Additional Resources (Synced)
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Source
AMBOSS Accessed 18 July 2024
Calgary Guide Accessed 18 July 2024
StatPearls Accessed 27 August 2025
Understanding Parkinson's Disease (YouTube) Accessed 10 January 2026
Calgary Guide Accessed 18 July 2024
StatPearls Accessed 27 August 2025
Understanding Parkinson's Disease (YouTube) Accessed 10 January 2026
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