Figure 9. GAD65/67 varicosities contact InsR immunoreactive cells.
Confocal micrographs illustrate GAD65/67 (red), synaptophysin (green), and InsR (blue) immunoreactivity within PVN at approximately –1.9 from Bregma (left) and –2.1 from Bregma (right). Representative diagrams of magnocellular and parvocellular regions are similar to Stocker et al. (2004) and are modified from the digital atlas of Paxinos and Watson (1998) with permission from the publisher. Left column: in the posterior magnocellular subnucleus (pm), most GAD 65/67-immunoreactive (-ir) varicosities that contain synaptophysin (yellow arrowheads) did not contain the insulin receptor (inset, top left). However, they did occasionally form appositions with InsR labelled cells (white arrows, inset bottom left). Insets represented by white rectangle. The dashed white line delineates the approximate boundary of the PVN. Right column: similar results are seen in the lateral parvocelluar subnucleus (lp). Images on left are 1.0 μm thick, composed of 3 consecutive optical sections. Images on right are 1.5 μm thick, composed of 4 consecutive optical sections. dp, dorsal parvocellular; mp, medial parvocellular; 3V, 3rd ventricle. Scale bar = 5 μm for all inset pictures and 20 μm for all low magnification images.