Figure 5.

Somatostatin afferents as a potential source of input to GRP-eGFP cells. (a–d) Somatostatin-expressing primary afferents were initially revealed in tissue from the Avil::eGFP mouse, by immunostaining for somatostatin (SST, red), eGFP (green) and prostatic acid phosphatase (PAP, blue). These images are from a single confocal optical section through lamina IIo and show two eGFP + boutons, both of which are also PAP-immunoreactive. One of these (arrow) is SST-positive, indicating that it originates from a SST-expressing primary afferent, while the other (arrowhead) lacks SST. (e) The distribution of SST-afferents revealed by coexpression of PAP and SST seen in a single 60 μm thick section. Note that these are largely restricted to lamina IIo. (f) Part of a sagittal section through lamina II from a GRP::eGFP mouse, immunostained to reveal PAP (blue), eGFP (green) and SST (red). The image is projected from 13 optical sections at 0.2 μm z-separation. Two large SST afferent boutons, identified by the presence of SST and PAP are close to the dendrite of a GRP-eGFP cell, but are not in direct contact. (g–j) Fluorescent in situ hybridisation on a section from a GRP::eGFP mouse shows two cells (arrows) that are labelled with probes against both Grp and eGFP mRNAs, and both of which are also NPR1-positive. Images in (g–j) are projections of confocal images (1 μm z-separation) taken through the full thickness of the section. Scale bars: (a–d) = 5 μm, (f) = 5 μm, (g–j) = 20 μm.