In order for a loaded neuron to be included in the analysis, it had to satisfy the following criteria: (1) lie within the pyramidal layer of the CA1 as defined by cytoarchitectural characteristics; (2) demonstrate complete filling of dendritic tree, as evidenced by well-defined endings; (3) demonstrate intact primary and secondary branches; (4) demonstrate intact tertiary branches, with the exception of branches that extended beyond 50 μm in radial distance from the cell soma (Duan et al., 2002; Duan et al., 2003; Radley et al., 2006). Neurons meeting these criteria were reconstructed in 3-dimension (3D) with a 63x/1.4 N.A., Plan-Apochromat oil immersion objective on a Zeiss Axiophot 2 microscope equipped with a motorized stage, video camera system, and Neurolucida morphometry software (MBF Bioscience, Williston, VT, USA). Using NeuroExplorer software (MBF Bioscience), total dendritic length, number of intersections and the amount of dendritic material per radial distance from the soma, in 30-μm increments (Sholl, 1953) were analyzed in order to assess morphological cellular diversity and potential differences among animal groups.
