Figure 2.

A, Mean (± SEM) proportion of CA1 pyramidal neurons that present intronic Arc pre-mRNA intranuclear foci staining (foci), Arc mRNA in the cytoplasm (cytoplasmic), and both (double), in the groups of animals killed at different time points after spatial exploration of a novel environment, *p < 0.01. Representative confocal images taken with a 40×/1.3 NA objective of the CA1 region from a caged control animal (B), an animal killed 5 min after spatial exploration (C), and an animal killed 30 min after spatial exploration (D).