α2-chimaerin immunoreactivity in adult brain.A, In the thalamus (AA), α2-chimaerin immunoreactivity was restricted to a subpopulation of cells, including the centrolateral (cl) and centromedial (cm) intralaminar nuclei and the midline paraventricular (pv)and rhomboid (rh) nuclei. Scale bar, 500 μm. AB, Cells in the dorsal cap (dc), lateromedial (lm), and ventral (v) portions of the paraventricular hypothalamic nucleus are immunoreactive in contrast with the light staining in the medial parvocellular (mp) subdivision. Scale bar, 200 μm. AC , Cells of the claustrum stain more strongly for α2-chimaerin compared with cells in adjoining cortex and striatum. Scale bar, 100 μm.AD , In the hippocampal formation, α2-chimaerin immunoreactivity is marked in the CA1 and CA3 pyramidal cell and dentate gyrus (dg) granule cell layers. Dendritic processes are clearly labeled in the stratum radiatum. A fine particulate staining is present in the stratum lacunosum moleculare and the outer two-thirds of the dentate gyrus molecular layer (arrows). Scale bar, 400 μm.AE , A higher power photomicrograph of the hippocampal formation at a more posterior level thanAD shows staining of dendrites in the stratum radiatum and axons in the adjacent internal capsule (open arrows). Scale bar, 100 μm.AF , In the medulla, immunoreactivity is localized to cells within the dorsal motor nucleus of the vagus nerve and inferior olivary complex. Some fiber tracts including the tractus solitarius (arrowhead) are also stained. Scale bar, 675 μm. B, α2-Chimaerin immunoreactivity in cortical regions at higher resolution shows layer VIa of the cerebral cortex contains many darkly stained neurons and another population of moderately stained neurons (BA ). Scale bar, 50 μm.BB, In the retrosplenial granular cortex, neurons in layer II and their dendritic processes, which bundle in a characteristic manner, are stained. Scale bar, 50 μm. BC , Immunoreactive neurons in the entorhinal cortex are found in both medial and lateral aspects. Most darkly stained neurons are located in layers II and III. Scale bar, 675 μm. BD , A high-power photomicrograph of cells in the entorhinal cortex shows the granular nature of the labeling that is localized to the perikaryal cytoplasm and processes but is excluded from the nucleus. Scale bar, 20 μm.
