Regional and cellular distribution of sst2A receptor immunoreactivity in the rat developing locus coeruleus.

<p>(A) At E18, strong sst2A receptor immunoreactivity is found not only in the rhombic lip (rl) and external granular layer (EGL) but also in the rostro-ventral part of the cerebellum between the cerebellar ventricular area (IV) and the ventral hindbrain (boxed area). B–B″) The large, elongated sst2A receptor-immunoreactive cells (red in B, B″) lie parallel with the ventricular surface. These neurons also express tyrosine hydroxylase (TH; green in B′, B″), a marker of catecholaminergic neurons. C) At E21, intense sst2A receptor immunoreactivity (red in C, C″) is observed in the developing locus coeruleus (LC) and overlap with TH immunolabeling (green in D′,D″). D represents high magnification of boxed area in C. Note that intense sst2A receptor immunoreactivity (red) outlines the periphery of TH-positive (green) neurons (arrowheads). E) At P3, the locus coeruleus exhibits also strong sst2A receptor immunoreactivity (red). The blue labeling represents DAPI staining. CB, cerebellum; IV, fourth ventricle. Scale bars: A, 200 µm; B–B″, C–C″, E, 100 µm; D–D″, 20 µm.