Effects of 17beta-estradiol on synaptic plasticity in the rat medial vestibular nuclei.
CONCLUSIONS
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.


OBJECTIVE
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.


METHODS
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.


RESULTS
HFS reversed the E(2)-induced potentiation in most cases, while E(2) was able to increase the magnitude of potentiation induced by HFS.
Grassi
Silvarosa
S
Department of Internal Medicine, Section of Human Physiology, University of Perugia, Perugia, Italy. sgrassi@unipg,it
Frondaroli
Adele
A
Dieni
Cristina
C
Scarduzio
Mariangela
M
D000818:Animals; D004558:Electric Stimulation; D004958:Estradiol / Q000008:administration & dosage / Q000502:physiology*; D066298:In Vitro Techniques; D017774:Long-Term Potentiation; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014726:Vestibular Nuclei / Q000502:physiology*
D004958:Estradiol