Figure 6

Abnormal cytoarchitecture of the dorsomedial pole of vldlr^−/−; lrp8^−/−mutant dLGN. Adamts15 mRNA, which is expressed by thalamic relay neurons, was labeled by in situ hybridization in (A) P14 control and (B) vldlr^−/−;lrp8^−/− mutant (DKO) LGN. Retinal arbors were labeled by binocular injection of Alexa Fluor 594 CTB. In (B), note the ectopic region of binocular retinal input in the dorsomedial pole of vldlr^−/−;lrp8^−/− dLGN is labeled with arrowheads. Insets in (A,B) show high magnification images of the areas indicated by boxes. (C,D) dLGN and vLGN relay neurons (and their dendrites) were labeled by SMI32-immunostaining and retinal terminals were labeled by VGluT2-IHC. Note the absence of SMI32-immunoreactivity in the dorsomedial pole of vldlr^−/−;lrp8^−/− mutant dLGN (asterisk). Also note the abnormal presence of SMI32-IR structures in vldlr^−/−;lrp8^−/− mutant IGL (arrowheads). Insets in (C,D) show high magnification images of the areas indicated by boxes, and single and double asterisks. (E,F) Corticothalamic terminals in control and mutant dLGN were labeled by VGluT1-IHC. Retinal arbors were labeled by binocular injection of Alexa Fluor 594 CTB. In (F), note the absence of VGluT1-immunoreactivity in the dorsomedial pole of vldlr^−/−;lrp8^−/− mutant dLGN (arrowheads). Insets in (E,F) show high magnification images of the areas indicated by boxes. For all images, the outline of the dLGN is depicted with white dots. dLGN are labeled ‘d’, vLGN are labeled ‘v’ and arrows indicate IGL. Scale bar = 180 μm for (A to F) and 50 μm for insets. CTB, cholera toxin B subunit; Ctl, control; DKO, double knockout; dLGN, dorsal LGN; IGL, intergeniculate leaflet; LGN, lateral geniculate nucleus; SMI32-IR, SMI32-immunoreactivity; VGluT1-IHC, vesicular glutamate transporter 1-immunohistochemistry; vLGN, ventral LGN.