Mastication stimuli enhance the learning ability of weaning-stage rats

The mastication stimuli during the weaning period can enhance the learning ability of rats by increasing the dendrite branches of hippocampal CA1 neurons and by regulating genes related to dendrite growth. Using DNA microarray analysis, differentially expressed genes were enriched in functional terms related to dendrite growth and included the Igf2, RhoA, and Rho GEF genes, most of which were upregulated in the chow diet group. Three-week-old male Wistar rats were administered powdered (P-gloup) or solid (C-gloup) feed and water ad libitum for eight days, and the mRNA expression in the hippocampus was compared between the two groups.