Heterogeneous distribution of D1, D2 and D5 receptor mRNAs in monkey striatum

M. S. Rappaport, S. C. Sealfon, A. Prikhozhan, G. W. Huntley, John Morrison

Research output: Contribution to journalArticle

58 Scopus citations

Abstract

The primate striatum has a compartmental organization reflected both in the topography of its afferent projections and in the segregation of its morphologically similar but neurochemically distinct efferent neurons. Discretely projecting mesostriatal neurons release dopamine (DA) which modulates the responses of striatal neurons to other afferent inputs. Multiple DA receptor (DAR) subtypes have been cloned and characterized and mapping their cellular expression is crucial for understanding the influence of DA on striatal function. We report the distribution of mRNAs for D1, D2 and D5 DAR subtypes (D1R, D2R and D5R) in the striatum of cynomolgus monkeys (Macaca fascicularis) studied by in situ hybridization histochemistry (ISH) using monkey-specific cRNA probes. Adjacent sections were stained for calbindin immunoreactivity to distinguish striosomal and matrix compartments for comparison with the patterns obtained with ISH. In the caudate nucleus, D1R mRNA was concentrated in calbindin-poor striosomes where dense grain clusters were seen overlying the majority of medium-sized neurons (diameter ∼ 15 μm). D1R mRNA localization was relatively homogeneous in the putamen. By contrast, the distributions of D2R and D5R mRNAs showed no clear preference for the striosomal or matrix compartments of either caudate nucleus or putamen. In the ventral striatum (nucleus accumbens, olfactory tubercle and ventral portions of caudate nucleus and putamen), expression of D1R and D2R mRNA was sparse relative to dorsal striatum, while D5R mRNA expression was roughly equal in ventral and dorsal striatum. Circumscribed zones of hybridization associated with islands of tightly packed small cells occurred with all three DAR mRNA subtypes in the ventral striatum. Large, putative cholinergic neurons which were seen in both the striatum and the adjacent basal forebrain, hybridized strongly with D2R and D5R cRNA probes but not with the D1R probe. The different yet partially overlapping regional and cellular expressions of D1R, D2R and D5R mRNAs suggest that the corresponding receptor subtypes subserve distinct functions in striatal neuronal processing.

Original languageEnglish (US)
Pages (from-to)242-250
Number of pages9
JournalBrain Research
Volume616
Issue number1-2
DOIs
StatePublished - Jul 9 1993
Externally publishedYes

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Keywords

  • Basal forebrain
  • Calbindin
  • In situ hybridization
  • Matrix
  • Striosome

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Developmental Biology
  • Clinical Neurology

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