Patterns of cortical Arc expression following learning in aged mice. (A), Representative heat maps showing the distribution of Arc mRNA expression in the aged mouse brain following learning, swimming, or home cage conditions. (B), Densitometric analysis revealed that learning increased Arc expression in the anterior cingulate cortex (AC), auditory cortex (Au), entorhinal cortex (Ent), somatosensory cortex (Ss), retrosplenial cortex (Rs), and visual cortex (Vis). The only cortical region that did not show increased Arc expression following learning was the motor cortex (M). Asterisk (*) indicates significance at p < 0.05 following one-way ANOVA with Tukey's post hoc. Abbreviations used in (A) are the same as those used in (B) and (C); see Materials and Methods for detailed description of cortical anatomical sampling. (C), Levels of Arc mRNA are lower in association cortices, relative to sensorimotor regions, under home cage conditions and following swimming without a target in the maze. Following learning, this difference is no longer significant, suggestive of changes in the pattern of cortical network activity.
Park et al. BMC Neuroscience 2011 12:63 doi:10.1186/1471-2202-12-63