Details

Autor(en) / Beteiligte

• Pettorossi, Vito E.
• Frondaroli, Adele
• Grassi, Silvarosa

Titel

Cyclic estrogenic fluctuation influences synaptic transmission of the medial vestibular nuclei in female rats

Ist Teil von

• Acta oto-laryngologica, 2011-04, Vol.131 (4), p.434-439

Ort / Verlag

Stockholm: Informa Healthcare

Erscheinungsjahr

2011

Quelle

MEDLINE

Beschreibungen/Notizen

• Abstract Conclusion: The estrous cycle in female rats influences the basal synaptic responsiveness and plasticity of the medial vestibular nucleus (MVN) neurons through different levels of circulating 17β-estradiol (cE2). Objective: The aim of this study was to verify, in the female rat, whether cyclic fluctuations of cE2 influence long-term synaptic effects induced by high frequency afferent stimulation (HFS) in the MVN, since we found that HFS in the male rat induces fast long-term potentiation (fLTP), which depends on the neural synthesis of E2 (nE2) from testosterone (T). Methods: We analyzed the field potential (FP) evoked in the MVN by vestibular afferent stimulation, under basal conditions, and after HFS, in brainstem slices of female rats during high levels (proestrus, PE) and low levels (diestrus, DE) of cE2. Selective blocking agents of converting T enzymes were used. Results: Unlike in the male rat, HFS induced three effects: fLTP through T conversion into E2, and slow LTP (sLTP) and long-term depression (LTD), through T conversion into DHT. The occurrence of these effects depended on the estrous cycle phase: the frequency of fLTP was higher in DE, and those of sLTP and LTD were higher in PE. Conversely, the basal FP was also higher in PE than in DE.