Dopaminergic neurons in the rat retina express dopamine D2/3 receptors.
The localization of dopamine D2 and D3 receptors in the rat retina was studied using a polyclonal antibody raised against a peptide sequence common to the dopamine D2 and D3 receptors (D2/3). The D2/3 receptor antibody labelled a small number of somata in the innermost part of the inner nuclear layer and in the ganglion cell layer and a small number of photoreceptor outer segments. Processes in both plexiform layers were also labelled. Double-labelling experiments with the antibody against the D2/3 receptor and an antibody against tyrosine hydroxylase to label dopaminergic neurons resulted in the co-localization of the two antibodies. This demonstrates directly that dopaminergic neurons in the retina express D2/3 receptors. As previous biochemical and physiological studies have demonstrated that activation of D2-like receptors inhibits the release of dopamine in the retina, the present results suggest that the D2/3 receptors on dopaminergic neurons function as autoreceptors.
Veruki
M L
ML
Max-Planck-Institut für Hirnforschung, Frankfurt, Germany.
D000818:Animals; D004298:Dopamine / Q000378:metabolism*; D007150:Immunohistochemistry; D009474:Neurons / Q000502:physiology*; D051381:Rats; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D050637:Receptors, Dopamine D3; D012160:Retina / Q000378:metabolism*
C493595:Drd3 protein, rat; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D004298:Dopamine