INDS 212 Lecture Notes - Lecture 36: Atypical Antipsychotic, Nucleus Accumbens, Dopamine Receptor D2

• School: McGill University
• Department: Interndisciplinary Studies
• Course: INDS 212
• Professor: Fraser Moore

Document Summary

Dopaminergic system: da hypothesis states: positive symptoms result from excess dopaminergic activity in the brain, particularly the mesolimbic (ventral tegmental area to temporal lobe and nucleus accumbens) da pathways. If there is da overactivity in schizophrenia, this could come about in several ways, including: Increased release of da: hypersensitive da receptors, underactivity of a neurotransmitter that normally inhibits da activity, overactivity of a neurotransmitter that normally enhances da activity. Increased number of da receptors: most widely accepted hypothesis, was formulated mainly on the basis of indirect evidence, antipsychotics block d2 receptors. Drugs which increase da transmission (e. g. amphetamine, cocaine, Antipsychotic treatment leads to an initial (feedback) increase in plasma. Hva followed by a gradual decrease correlating with symptom reduction: there is an increase in d2 receptors in the nucleus accumbens, caudate-putamen and olfactory tubercles of schizophrenia patients (post-mortem and pet studies). This has been replicated in antipsychotic-free and never medicated subjects.