Rapid Nongenomic Modulation by Neurosteroids of Dendritic Spines in the Hippocampus: Androgen, Estrogen, and Corticosteroid

This review article discussed the rapid nongenomic modulation of dendritic spines in the hippocampus by neurosteroids, including androgens, oestrogens, and corticosteroids. The authors described kinase-dependent signaling mechanisms that explain how sex steroids like dihydrotestosterone, testosterone, oestradiol, and progesterone rapidly modulate dendritic spinogenesis in rat and mouse hippocampal slices. They also explored the role of synaptic sex steroid receptors in these rapid synaptic modulations and examined the effects of corticosterone in an acute stress model. The findings were primarily based on optical imaging of dendritic spines, with comparisons to electron microscopic imaging. The study highlighted that the rapid effects of exogenously applied oestrogen and androgen were mostly observed in steroid-depleted conditions, suggesting these effects might be akin to hormone replacement therapy. In contrast, in young animals with high endogenous sex hormone levels, further hormone supplementation might be ineffective, whereas blocking steroid receptors or kinases could suppress sex hormone functions, offering insights into molecular mechanisms.