Human striatal dopamine receptors are organized in compartments.

AUTOR(ES)

Joyce, J N

RESUMO

Dopamine (D2) receptors visualized in postmortem human striatum by quantitative autoradiography of [3H]spiroperidol binding are organized into circumscribed zones of low receptor density separated from other such zones by regions of higher D2 density. The D2-rich zones of the caudate nucleus and putamen contain twice the binding of D2-poor zones. The Hill coefficient, obtained from saturation analysis of [3H]spiroperidol binding to thin sections of human striatum, gave a value near unity, indicating the binding was occurring to a single type of site. The patchiness of [3H]spiroperidol binding was unaltered by postincubation removal of lipid from the tissue sections, indicating that a differential absorption of tritium in white and grey matter does not account for the heterogeneous distribution. The D2-rich and D2-poor regions appear to form labyrinths oriented in the anterior-posterior axis and are typically aligned with, respectively, acetylcholinesterase-rich and -poor compartments as visualized on stained adjacent sections. Thus, the distribution of dopamine D2 receptors conforms to the "striosomal" organization of the human caudate-putamen, a finding that suggests that this receptor subtype may mediate the influence of dopamine on distinct neurochemical compartments within the structure.

Documentos Relacionados

• Dopamine uptake sites in the striatum are distributed differentially in striosome and matrix compartments.
• Human immunodeficiency virus type 1 Gag proteins are processed in two cellular compartments.
• Striatal dopamine D2 receptors in tardive dyskinesia: PET study.
• Effect of vigabatrin on striatal dopamine receptors: evidence in humans for interactions of GABA and dopamine systems.
• Altered striatal function in a mutant mouse lacking D1A dopamine receptors.