TY  - JOUR
TI  - Sexual dimorphism in estrogen-induced synaptogenesis in the adult hippocampus
AU  - Brandt, Nicola
AU  - Vierk, Ricardo
AU  - Rune, GabrieleM.
T2  - The International Journal of Developmental Biology
AB  - It has long been known that estradiol influences synaptic plasticity in the female hippocampus. The density of dendritic spines varies during the estrous cycle and correlates positively with varying levels of estradiol in serum. In accordance, ovariectomy results in a loss of spines that can be rescued by estradiol treatment in animals, suggesting that estradiol originating from the ovaries induces spine formation in the hippocampus. More recent studies point to a role of hippocampus-derived estradiol in synaptogenesis in the female hippocampus, rather than of estradiol of ovarian origin. In our studies, we have shown that inhibition of hippocampal estrogen synthesis results in spine synapse loss in female animals and, more importantly, also in ovariectomized animals. Surprisingly, inhibition of local estradiol synthesis had no effect on synapse formation in males, in spite of a similar capacity to synthesize estradiol in male and female hippocampal neurons. In females, neuro-sexual steroid production is promoted by hypothalamic, cyclic GnRH release and likely underlies the estrus cyclicity of spine synapse density in the hippocampus. As a result, peripheral serum concentrations of estradiol determine the amount of estradiol synthesis in the hippocampus. This paradigm may also be true in males. In support of this hypothesis, we found that the content of estradiol in hippocampal tissue is higher in female compared to that in male animals, with low levels of estradiol in serum and tonic and acyclical GnRH release. In summary, our data point to important sex-specific differences in sexual steroid-induced synaptogenesis.
PY  - 2013
DO  - 10.1387/ijdb.120217gr
VL  - 57
IS  - 5
SP  - 351
EP  - 356
J2  - Int. J. Dev. Biol.
LA  - en
SN  - 0214-6282
SN  - 1696-3547
UR  - https://ijdb.ehu.eus/article/120217gr
Y2  - 2024/11/21/23:32:46
ER  -