Injury-induced reorganization of frequency maps in adult auditory cortex: the role of unmasking of normally-inhibited inputs.
Injury-induced reorganization of frequency maps in adult auditory cortex: the role of unmasking of normally-inhibited inputs.
复制标题
成人听觉皮层中损伤引起的频率图重组：揭示正常抑制输入的作用。
DOI：
10.3109/00016489709126143
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
R. Rajan
中科院分区：
文献类型：
--
作者：
D. Irvine;R. Rajan
成年动物的局限性耳蜗病变导致部分耳聋，导致初级听觉皮层（AI）的重组，使得被病变剥夺正常输入的区域被病变周围耳蜗区域的扩大表示所占据，因此病变周围的频率也随之增加。这种重组中频率响应性变化的一种可能机制是，皮层神经元在其“新的”损伤后特征频率（CFs）附近的频率输入通常存在，但被抑制抑制，并被损伤的影响“揭开”。支持这一解释的证据是由双音前向掩蔽实验提供的，该实验揭示了许多人工智能神经元接收周围抑制输入。当这些神经元在其CF处的输入被强烈的临时阈值移位（TTS）诱导刺激减少时，一些神经元的反应区域扩展到其抑制周围的区域，如果暴露涉及皮质重组，则会产生预期的效果。然而，在其他神经元中，反应区在tts诱导刺激后收缩。尽管正常抑制输入信号的释放可能有助于听觉皮层重组，但在视觉和体感觉系统中发现的立即释放不太可能在听觉皮层重组中发挥主要作用，因为在豚鼠急性耳蜗损伤后没有发现立即释放的证据。
Restricted cochlear lesions in adult animals, causing partial deafness, result in a reorganization of primary auditory cortex (AI) such that the region deprived of its normal input by the lesion is occupied by an expanded representation of peri-lesion cochlear regions, and hence of peri-lesion frequencies. One possible mechanism underlying the change in frequency responsiveness involved in such reorganization is that inputs to the cortical neurons at frequencies at and near their "new" post-lesion characteristic frequencies (CFs) are normally present but suppressed by inhibition, and are "unmasked" by the effects of the lesion. Evidence in support of this explanation is provided by two-tone forward-masking experiments which reveal that many AI neurons receive surround inhibitory input. When input to such neurons at their CF is reduced by an intense temporary-threshold-shift (TTS)-inducing stimulus, the response areas of some neurons expand into the region of their inhibitory surrounds, the effect that would be expected if unmasking were involved in cortical reorganization. In other neurons, however, response areas contracted after the TTS-inducing stimulation. Although unmasking of normally-inhibited inputs is likely to contribute to auditory cortical reorganization, the immediate unmasking that is seen in visual and somatosensory systems is unlikely to play a major role in auditory cortical reorganization, as no evidence of immediate unmasking was seen following acute cochlear lesions in guinea pigs.
影响因子：
13.9
作者：
N. Weinberger
通讯作者：
N. Weinberger
耳蜗听力损失后成年灵长类动物听觉皮层的神经可塑性。
DOI：
--
发表时间：
1993
期刊：
The American journal of otology
影响因子：
--
作者：
Schwaber,MK;Garraghty,PE;Kaas,JH
通讯作者：
Kaas,JH