â– LECTURE OVERVIEW: Schizophrenia is a chronic, heterogeneous psychiatric disorder characterized by a disintegration of thought processes and emotional responsiveness.
â– DOPAMINERGIC PATHWAYS & RECEPTORS:
1. Positive Symptoms (Excess/distortion of normal function):
- Manifestations: Hallucinations, delusions, disorganized speech, and grossly disorganized behavior.
- Pathway: Driven by dopamine hyperactivity at D2 receptors selectively in the Mesolimbic pathway of the brain.
2. Negative Symptoms (Loss of normal function):
- Manifestations: Apathy, flat affect, alogia (poverty of speech), anhedonia, and social withdrawal.
- Pathway: Driven by relative dopamine hypoactivity at D1 receptors in the Mesocortical pathways.
â– SURGICAL LANDMARKS & ANATOMICAL BOUNDARIES:
Intraoperative access requires meticulous dissection along defined tissue planes. Avoid excessive traction near neurovascular bundles and look for key bony landmarks or fascial reflections to secure margins.
â– HISTOCHEMICAL & SPECIAL STAIN ANALYSIS:
Tissue examination is enhanced by specialized dyes and immunophenotypic markers that target cellular structure with remarkable specificity.
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🌟 Dynamic Clinical Key:
First-generation antipsychotics (e.g., Haloperidol, Chlorpromazine) are potent D2 blockers that treat positive symptoms but can worsen negative symptoms and cause extrapyramidal side effects. Second-generation atypical antipsychotics (e.g., Aripiprazole, Clozapine, Olanzapine) block 5-HT2A receptors alongside D2, offering better management of negative symptoms. Never divide or ligate any vessel before clearly isolating and confirming its origin and termination. Always cross-reference histochemical stains with structural boundaries on the biopsy.