Figure 1.

The Embryonic Origin of MSvDB Septohippocampal Projection Neurons

(A) Expression of NKX2-1 in the MGE and in a caudo-ventral domain of the septal neuroepithelium (E13.5). The entire septum is labeled with YFP in Zic4-Cre;R26R-YFP mice. The overlap between NKX2-1 and YFP is restricted to the septum (arrows). The boxed areas in (A) and (B) are shown in higher magnification.

(B) In Nkx2-1-Cre;R26R-YFP E13.5 embryos, expression of YFP is detected in the MGE, the POA, and the caudo-ventral septum that co-expresses Zic4 (arrows).

(C) Quantification of the contribution of Nkx2-1-Cre- and Zic4-Cre-expressing progenitors to MSvDB neurons expressing PV, VG2, and p75^NTR. Data show mean ± SEM.

(D) Double IHC for YFP and PV or p75^NTR and IHC for YFP followed by ISH for VG2 in adult Zic4-Cre;R26R-YFP and Nkx2-1-Cre;R26R-YFP animals.

(E) P75^NTR cholinergic neurons of the MSvDB co-express tdTomato (tdT) in Zic4-CreER^T2;R26R-tdT mice where recombination had been induced at E9.5.

Scale bars: 100 μm, (higher magnifications 50 μm) in (A) and (B) and 20 μm in (D) and (E). See also Figure S1.