Figure 2.

NOS-Fos and NOS-AR co-localization in male gerbils. Photomicrographs of coronal sections showing the co-localization of NOS (blue-purple) and Fos after ejaculation (brown; A, B, D, E, G, H), or the co-localization of NOS and AR (brown; C, F, I–K), in and near the PdPN (A–C), lateral MeApd (D–F), MPNm (G–I), BSTpr (J), and VMH (K). A: Fos-IR cells are intermingled with NOS cells in the PdPN and BSTpr of recently mated males. The BSTpr contains a dense plexus of NOS fibers, and a distinct circle of NOS cells can be seen just below the fornix (fx). B: Higher magnification of the PdPN shown in A showing NOS-Fos double-labeled cells (arrowheads). C: NOS-AR double-labeled cells are common in the PdPN (arrowheads). D: Dense plexus of NOS fibers surrounding NOS cells in the medial MeApd, near the optic tract (ot), but not NOS cells in the lateral MeApd, where a cluster of Fos-IR cells appears at ejaculation (arrow). E: Higher magnification of the lateral MeApd Fos cluster in D showing NOS-Fos double-labeled cells (arrowheads). F: NOS-AR double-labeled cells (arrowheads) are abundant in the lateral MeApd. G: NOS and Fos-IR cells in the MPNm. The MPNc has few, if any, Fos-IR cells but is filled with NOS fibers. H: Higher magnification of the MPNm in D showing NOS-Fos double-labeled cells (arrowheads). I: Some NOS-AR double-labeled cells (arrowheads) were found in the MPNm. J, K: The dorsal BST (J) and VMH (K) had many NOS-AR double-labeled cells (arrowheads). Arrowheads point to only some of the double-labeled cells visible in B, C, E, F, H–K. For abbreviations, see list. Scale bar = 50 μm in A (also applies to D, G; 10× objective); 20 μm in B (also applies to C, E, F, H–K; 40× oil objective).