Antipsychotic-induced parkinsonian rigidity and bradykinesia are explained by dopamine D2 receptor blockade in which of the following pathways?
- A Mesolimbic pathway
- B Mesocortical pathway
- C Nigrostriatal pathway ✓
- D Tuberoinfundibular pathway
Correct answer: C. Nigrostriatal pathway
Explanation
The nigrostriatal pathway projects from the substantia nigra pars compacta to the striatum and regulates motor output. D2 blockade here produces drug-induced parkinsonism, acute dystonia and other extrapyramidal side effects. Blockade in the tuberoinfundibular pathway raises prolactin causing galactorrhoea and amenorrhoea, while therapeutic antipsychotic effect comes from limbic blockade, not cortical or motor tract blockade.
Reference: Stahl's Essential Psychopharmacology, 5th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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