Senior graduate student Jen Tuscher is the first author on a new paper in the Journal of Neuroscience (Tuscher et al., 2016, J Neurosci, 36(5):1483-1489), published with collaborators Maya Frankfurt (Hofstra North Shore-LIJ School of Medicine) and Victoria Luine (Hunter College).  The paper examined the involvement of dorsal hippocampal extracellular signal-regulated kinase (ERK) and mammalian target of rapamycin (mTOR) signaling mechanisms in estrogenic regulation of dendritic spine density in the hippocampus and medial prefrontal cortex.  Our lab previously showed that activation of ERK and mTOR in the dorsal hippocampus is necessary for estradiol to enhance spatial memory and object recognition in ovariectomized female mice.  In this new paper, we first found that dorsal hippocampal infusion of estradiol selectively increases dendritic spine density not only in the dorsal hippocampus, but also in the prefrontal cortex, suggesting that estrogenic regulation of the hippocampus influences prefrontal spinogenesis.  Next, we demonstrated that activation of ERK or mTOR signaling in the dorsal hippocampus is necessary for estradiol to increase dendritic spine density in both the hippocampus and prefrontal cortex.  Thus, this study is the first to show that cell signaling regulates estradiol-induced spine formation in the dorsal hippocampus, and that this hippocampal spine formation drives spinogenesis in the prefrontal cortex.