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Distribution of dopamine D 1 and D 2 receptors in rabbit cortical areas, hippocampus, and neostriatum in relation to dopamine contents
Author(s) -
Dewar Karen M.,
Reader Tomás A.
Publication year - 1989
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/syn.890040413
Subject(s) - raclopride , dopamine , dopaminergic , chemistry , dopamine receptor d1 , medicine , dopamine receptor , endocrinology , hippocampus , entorhinal cortex , dopamine receptor d2 , nomifensine , neuroscience , biology
The densities of dopamine D 1 and D 2 receptors were measured by using [ 3 H]SCH23390 and [ 3 H]reclopride, respectively, in the rabbit cingulate, visual, sensorimotor, and entorhinal‐piriform cortical areas; the dorsal and ventral hippocampus; and the putamen as well as the medial and lateral caudate. Endogenous dopamine (DA) and its metabolites 3,4‐dihydroxyphenylacetic acid (DOPAC), 4‐hydroxy‐3‐methoxyphenylacetic acid (HVA), and 3‐methoxytyramine (3‐MT) were assayed by HPLC with electrochemical detection. The distributions of [ 3 H]SCH23390 and [ 3 H]raclopride binding were heterogenous with the greatest densities in the neostriatum. The concentrations of DA and its metabolities were also highest in this structure. Regions with low DA content, i.e., cortex and hippocampus, had lower densities of [ 3 H]SCH23390 and [ 3 H]raclopride binding. Furthermore, these sites were differentially localized within the various regions and there were substantially more D 1 and D 2 receptors. The functional significance and heterogeneities in the distribution of D 1 and D 2 receptors are discussed in relation to the dopaminergic innervation and the turnover estimated by the ratios between endogenous DA and its metabolites.