Figure 5.

Aging does not alter Arc expression induced by maximal electroconvulsive shock (MECS). (A) Representative confocal images (scale bar = 60 μm) show that, following MECS, the vast majority of cells express Arc within punctuate intranuclear foci, although a small number of cells can be seen expressing Arc within the cytoplasm (arrows). This general trend is true for CA1 and CA3 of the hippocampus, as well as the suprapyramidal (FD_SP) and infrapyramidal (FD_IP) blades of the fascia dentata of both young and aged animals, and can be clearly seen in quantitative data, showing that approximately 90% of principal cells in the hippocampus proper (B) and the fascia dentata (C) express Arc within the nucleus (all data are mean ± SEM; * p < 0.05, ** p < 0.01 CA1 vs. CA3).