Guilding Clare, Dutia Mayank B
Centre for Integrative Physiology, Biomedical Sciences, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.
Neuroreport. 2005 Sep 8;16(13):1415-8. doi: 10.1097/01.wnr.0000176519.42218.a6.
Medial vestibular nucleus neurons develop a sustained increase in electrophysiological excitability after deafferentation, which may be an important component of 'vestibular compensation' (the behavioural recovery that follows peripheral vestibular lesions). We investigated the effects of gamma-aminobutyric acid, glutamate and glycine receptor blockade on the spontaneous activity of deafferented medial vestibular nucleus neurons in slices, to determine whether changes in synaptic inputs contribute to their increased excitability. Soon after deafferentation (4 h after labyrinthectomy) synaptic blockade had no effect on the elevated in-vitro firing of medial vestibular nucleus neurons, while later (48 h, 1 week), synaptic blockade reduced the elevated activity to normal. Intrinsic mechanisms therefore appear to mediate the elevated excitability of medial vestibular nucleus cells initially after deafferentation. Subsequently, changes in the efficacy of synaptic inputs are implicated, presumably involving intranuclear projections that are preserved in slices.
去传入后，内侧前庭核神经元的电生理兴奋性持续增加，这可能是“前庭代偿”（外周前庭损伤后的行为恢复）的一个重要组成部分。我们研究了γ-氨基丁酸、谷氨酸和甘氨酸受体阻断对切片中去传入内侧前庭核神经元自发活动的影响，以确定突触输入的变化是否导致其兴奋性增加。去传入后不久（迷路切除术后4小时），突触阻断对内侧前庭核神经元体外放电升高没有影响，而在后期（48小时、1周），突触阻断将升高的活动降低至正常水平。因此，内在机制似乎在去传入后最初介导内侧前庭核细胞兴奋性的升高。随后，突触输入效能的变化被认为与之有关，推测涉及切片中保留的核内投射。
