Figure 3.

The frequency of neurons generated during midneurogenesis is altered in mutant mice lacking ERK1 and/or ERK2. a, b, The number of NeuN+ neurons (green) across 10 equally spaced cortical bins in WT and CKO mice (a) quantified at P2 (b). Bin 2–3 corresponds to supragranular neurons in layers II–IV and bin 7 corresponds to layer V (b). The frequency of neuronal birth was analyzed at P2 by examining the number of BrdU+/DAPI+ cells that were labeled with BrdU (green) at E14.5 (a). c–e, For layer II–IV analysis, mice were labeled with BrdU (red) at E14.5 and evaluated for Brn1 coexpression (green) at P2 (p ≤ 0.0001) (c, d). Layer V neurons were BrdU (green) labeled at E12.5 and coexpression with Ctip2 evaluated at P2 (red); (p = 0.0032) (c, e). Minimum of six mice evaluated per genotype.