Fig. 2.

Colocalization of ERs with BDNF and GABA in primary cultures of hippocampal cells. Double-label fluorescent immunocytochemistry was used to colocalize ERα, but not ERβ, and BDNF in embryonic hippocampal cell cultures grown in vitro for 5 d. Each panel is an overlay of ERα or β and BDNF or GABA immunofluorescence. ER immunoreactivity is visualized as red fluorescence, whereas BDNF or GABA immunoreactivity is green. A, Most immunopositive cells were ERα⁺/BDNF⁺(arrows), although some BDNF⁺ cells were observed that expressed little or no ERα immunoreactivity (arrowheads). B, Essentially no ERβ immunoreactivity was coexpressed with BDNF, and the nuclei of these cells are unstained (arrowheads). C, No cells were observed that express ERα and GABA, although ERα-positive cells (arrows) and GABAergic processes (arrowheads) are clearly visible. Although most of the GABA immunoreactivity was concentrated to neuronal processes (arrowheads), we did observe scattered GABA-positive cell bodies that were always ERα-negative (asterisks). Scale bar, 25 μm.