Distribution of putative D4 dopamine receptors in postmortem striatum from patients with schizophrenia

摘要: The identification of five dopamine receptor subtypes has given the hypothesis schizophrenia new life. D4 is particularly intriguing because it binds clozapine with high affinity. Putative receptors were labeled in postmortem human brain by subtracting binding a saturating concentration 3H-raclopride (6 nM, which labels D2 and D3 receptors) from that [3H]YM 0915–2 (1–1.3 D2, D3, receptors). In control brain, putative show homogenous distribution striatum nucleus accumbens. This also true schizophrenic brains, although levels are significantly higher (twofold). These data inconsistent mRNA studies have shown negligible amounts accumbens, modest reported most cerebral cortex. findings suggest not synthesized this region, but presynaptically localized on striatal afferent terminals. Our confirm extend report Seeman et al. (1993). Extension these into accumbens important its extensive connections to limbic system while putamen exclusively “motor” striatum.