Three cases representative of WGA-HRP injections into the SON are illustrated diagrammatically in Fig. 1. Injections aimed at the SON can be placed into two general groups. In the first group, representing approximately one-third of the injections (6 animals BR773, not shown BR774,778,779,785,789,790), WGA-HRP was largely confined to the SON unilaterally and extended throughout the rostrocaudal length of the nucleus (Fig. 1, BR773; Table 1, BR770, 773). Although the SON was heavily labeled with WGA-HRP the adjoining lateral hypothalamic region dorsal to the SON was also labeled to varying extents. The WGA-HRP staining found in the lateral hypothalamic area, however, often represented the most diffuse portion of the WGA-HRP injection site. The distribution of WGA-HRP-positive neurons resulting from an injection limited mainly to the SON is detailed in Fig. 2 BR770) and Table 1 (BR770 and 773) and is representative of all similar WGA-HRP injections. |