Presence of D1- and D2-like dopamine receptors in the rat, mouse and bovine multiciliated ependyma.

The multiciliated ependyma forms an epithelial-like layer that could act as a selective barrier between the brain parenchyma and cerebrospinal fluid. In the present study, tyrosine hydroxylase-containing fibres have been detected in the basal pole of the ependymal cells of the lateral ventricles of rat, mouse and calf. The use of antibodies against at least two different peptide sequences of each D(2), D(3), D(4) and D(5) dopamine receptor subtype has allowed their detection in: (i) sections of mouse, rat and bovine lateral ventricles, by means of immunocytochemistry; and (ii) membrane protein extracts obtained from the ependymal layer of the bovine lateral ventricles, using immunoblotting. The immunocytochemical study has shown the presence of all these subtypes of dopamine receptors in the ependymal cells. Immunoblotting demonstrated similar immunoreactive bands for all receptor subtypes in both ependymal and corpus striatum membrane extracts.