Localization of dopamine D4 receptors in GABAergic neurons of the primate brain.
Dopamine receptors are the principal targets of drugs used in the treatment of schizophrenia. Among the five mammalian dopamine-receptor subtypes, the D4 subtype is of particular interest because of its high affinity for the atypical neuroleptic clozapine. Interest in clozapine stems from its effectiveness in reducing positive and negative symptoms in acutely psychotic and treatment-resistant schizophrenic patients without eliciting extrapyramidal side effects. We have produced a subtype-specific antibody against the D4 receptor and localized it within specific cellular elements and synaptic circuits of the central nervous system. The D4-receptor antibody labelled GABAergic neurons in the cerebral cortex, hippocampus, thalamic reticular nucleus, globus pallidus and the substantia nigra (pars reticulata). Labelling was also observed in a subset of cortical pyramidal cells. Our findings suggest that clozapine's beneficial effects in schizophrenia may be achieved, in part, through D4-mediated GABA modulation, possibly implicating disinhibition of excitatory transmission in intrinsic cortical, thalamocortical and extrapyramidal pathways.
Mrzljak
L
L
Yale School of Medicine, Section of Neurobiology, New Haven, Connecticut 06510, USA.
Bergson
C
C
Pappy
M
M
Huff
R
R
Levenson
R
R
Goldman-Rakic
P S
PS
D000818:Animals; D000918:Antibody Specificity; D001479:Basal Ganglia / Q000737:chemistry / Q000378:metabolism; D001483:Base Sequence; D001923:Brain Chemistry; D002460:Cell Line; D017931:DNA Primers; D004926:Escherichia coli; D006801:Humans; D007158:Immunologic Techniques; D007395:Interneurons / Q000737:chemistry; D008253:Macaca mulatta; D008969:Molecular Sequence Data; D009474:Neurons / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D017448:Receptors, Dopamine D2 / Q000032:analysis* / Q000276:immunology; D050638:Receptors, Dopamine D4; D011994:Recombinant Proteins / Q000276:immunology; D013788:Thalamus / Q000737:chemistry / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D017931:DNA Primers; C493599:DRD4 protein, human; D017448:Receptors, Dopamine D2; D011994:Recombinant Proteins; D050638:Receptors, Dopamine D4; D005680:gamma-Aminobutyric Acid