D receptor mRNA expression

In the normal adult human brain, the cells expressing the Di mRNA are localized predominantly within the striatum, cerebral cortex and bed nucleus of the stria terminalis (Hurd et al., 2001). There is extremely low or no appreciable detection of D mRNA expression in the hippocampus, diencephalon, brainstem, or the cerebellum indicating that neurons situated in those regions have no major role in mediating Di receptor regulated functions in marked contrast to the multitude of D2 and D3 receptor mRNA-expressing neurons in discrete populations in some of these brain areas (see Sections 2.3.3 and 2.3.5). 

In addition to the striatum, the bed nucleus of the stria terminalis and interface islands (apparent homolog to the islands of Calleja in rodents) within the ventral striatum show intense Di mRNA expression levels in the human brain (Hurd et al., 2001 Fig. 7). These regions are implicated in limbic function and thus have important relevance for the impaired Di transmission in psychiatric disorders. The Di mRNA is normally not detected in the thalamus, hypothalamus, hippocampus, pallidum, cerebellum, substantia nigra, pons, raphe and other brainstem nuclei of the normal human brain. 

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