Decrease in CA and DG neuron density in nes- igf1r-/Wtmice following H/I injury. A - D. Representative microphotographs of contralateral (A and C) and ipsilateral (B and D) HIP and DG of a control mouse at 3 DAI. Panels C and D are high magnification of areas (black rectangle) shown in panels A and B, respectively. White letters and associated red dashed lines in A and B indicate the areas used to measure the density of neurons and pyknotic cells where 1 is the pyramidal neuron layer (PCL) in CA1, 2 is PCL in CA2, 3 is PCL in CA3, and 4 is the granule cell layer (GCL) in DG. In panel D, red arrowheads show healthy appearing neurons and black arrows point to pyknotic cells. Neurons were identified morphologically. E. Quantification of neuron density in the PCL of CA1 to CA3 and in GCL of DG. Values represent mean ± SE from 6 - 10 brains in each group. Neuronal cell density is expressed as a percentage of contralateral. *, p < 0.05; **, p < 0.01, compared to control mice.