Estrogenic regulation of spinogenesis in the dorsal hippocampus and medial prefrontal cortex; Journal of Neuroscience (36: 1483-9)
Jennifer Tuscher is the first author on a recently published article in the Journal of Neuroscience (36: 1483-9) showing that direct infusion of 17b-estradiol into the dorsal hippocampus not only increased spine density in CA1, but also in the medial prefrontal cortex (mPFC), suggesting that estrogenic regulation of the dorsal hippocampus influences spinogenesis in the mPFC. Tuscher and co-authors Maya Frankfurt, Vicky Luine, and Karyn Frick also found that the estradiol-mediated increases in CA1 and mPFC spine density were blocked by inhibition of ERK and mTOR cell signaling in the dorsal hippocampus. These findings fit with previous work from the Frick lab showing that activation of extracellular signal-regulated kinase (ERK) and mammalian target of rapamycin (mTOR) signaling in the dorsal hippocampus is necessary for estradiol to enhance memory consolidation. Collectively, the new findings provide the first evidence that estradiol infusion in the hippocampus can regulate spinogenesis in the mPFC and that estradiol-mediated spinogenesis in the hippocampus and mPFC depends on rapid activation of cell signaling pathways, which the investigators believe may support the memory-enhancing effects of estradiol.
This research sheds new light on the molecular mechanisms underlying estradiol-induced spine changes, and suggests that the DH and mPFC may interact to mediate the memory-enhancing effects of estradiol.