Grassi Silvarosa, Frondaroli Adele, Dieni Cristina, Scarduzio Mariangela
Department of Internal Medicine, Section of Human Physiology, University of Perugia, Perugia, Italy. sgrassi@unipg,it
Acta Otolaryngol. 2009 Apr;129(4):390-4. doi: 10.1080/00016480802566287.
This study shows that 17beta-estradiol (E(2)) can amplify the long-term potentiation (LTP) induced in the vestibular nuclei by high frequency stimulation (HFS), while potentiation induced by E(2) alone, which is unrelated to synaptic high frequency activation, is reversed by HFS.
Like HFS, exogenous E(2) induces long-lasting enhancement of synaptic responses to vestibular afferent stimulation in the medial vestibular nuclei (MVN), through NMDA receptor activation. The aim of this study was to verify the possible interaction of E(2) and HFS in inducing LTP.
In rat brainstem slices, we analysed the modifications induced in the field potential evoked in the MVN by: 1) HFS delivered after induction of E(2) effect and 2) E(2) applied after induction of HFS-LTP.
HFS reversed the E(2)-induced potentiation in most cases, while E(2) was able to increase the magnitude of potentiation induced by HFS.
本研究表明，17β-雌二醇（E₂）可增强高频刺激（HFS）在前庭神经核中诱导的长时程增强（LTP），而单独由E₂诱导的、与突触高频激活无关的增强作用，会被HFS逆转。
与HFS一样，外源性E₂通过NMDA受体激活，在内侧前庭神经核（MVN）中诱导对前庭传入刺激的突触反应产生持久增强。本研究的目的是验证E₂与HFS在诱导LTP过程中可能存在的相互作用。
在大鼠脑干切片中，我们分析了以下因素对MVN中诱发的场电位所产生的改变：1）在诱导E₂效应后施加HFS；2）在诱导HFS-LTP后应用E₂。
在大多数情况下，HFS逆转了E₂诱导的增强作用，而E₂能够增加HFS诱导的增强幅度。
