Gene expression profile of Estrogen Receptors alpha and beta in rat brain during aging and following high fat diet.

The “sex-hormone” estrogen-17β promotes several cognitive functions and is a master regulator of brain bioenergetics via the estrogen receptors α and β (ERα and ERβ). In this work, by using Real Time PCR analysis, we evaluated the effect of aging and high fat diet (HFD) on ERα and ERβ expression in rat hippocampus and cortex. In young rats ERβ is abundant in cortex and ERα in hippocampus. During the aging, in the cortex we observe a general decrease in ERα and ERβ expression; in hippocampus ERα increases and ERβ decreases. ERs expression patterns in rat brain are also affected by the administration of a HFD. In cortex, after 4 weeks of HFD ERβ transcripts are down-regulate whereas ERα levels remain unchanged; after 12 weeks both ERα and ERβ expression is up-regulated. In hippocampus, the level of ERβ transcripts does not change following HDF, whereas ERα expression is affected by HDF, in a time-dependent manner: it increases after the 4 weeks treatment and decreases after 12 weeks. Possible involvements of these receptors in the control of cortex and hippocampus functions during aging and in the modulation of energetic metabolism and feeding behaviour are discussed.