Fig. 6.

Lef1 expression in the ventral telencephalon of cultured slices hosting two EmT explants. a A schematic representation of Lef1 expression in this group. The region of the tau-GFP donor tissue from which the two EmTs were taken from is shown in green. In 1/10 of slices analysed, Lef1 was not detected in the ventral telencephalon; in 2/10 slices, Lef1 was seen only in the ventricular zone (VZ); and in 7/10 slices, Lef1 was seen in the VZ and mantle layer. (b) Double immunofluorescence for GFP (green) and Calretinin (CR) (red) on a section from a cultured slice hosting two EmT explants (asterisk) on the left half of the brain. b ¹ is a magnification of the region indicated in b. The explants are both GFP and Calretinin positive confirming that these are EmT tissue. c Lef1 immunohistochemistry (brown staining) counterstained with cresyl violet (blue staining) on a consecutive section to that shown in b reveals staining in cells peripheral to the explants (green arrowhead). These Lef1-positive cells surrounding the explants are not GFP-positive as inferred from their positions in b¹ (white arrowheads) and c¹ (green arrowheads). b ¹ and c¹ are magnification of the regions indicated in b and c, respectively. c ² is a magnification of the region indicated in c ¹. d and e are serial sections from a slice hosting two EmT explants on one half of the ventral telencephalon. In e, where there is no EmT explant remaining, Lef1 staining is found in the VZ and mantle layer. The arrowhead points to Lef1 expression limited at the ventricular zone of the untreated hemisphere. e ¹ is a magnification of the Vtel shown in e. Lef1-positive cells found in the ventral telencephalon (arrowheads) are not GFP-positive suggesting that they may be host cells. The section is counterstained with DAPI (blue). The dashed curves delineate the limits between the ventral telencephalon and the thalamus and/or dorsal telencephalon. Abbreviations: CP choroid plexus; dmt dorsomedial telencephalon, EmT eminentia thalami; nctx neocortex; PTh prethalamus, Th thalamus, Vtel ventral telencephalon. Scale bars b, c, d, e = 250 μm; b¹, c¹, e¹ = 50 μm; c² = 20 μm