CONTRIBUTION OF GABAERGIC INHIBITION TO THE RESPONSE CHARACTERISTICS OF AUDITORY UNITS IN THE AVIAN FOREBRAIN
CONTRIBUTION OF GABAERGIC INHIBITION TO THE RESPONSE CHARACTERISTICS OF AUDITORY UNITS IN THE AVIAN FOREBRAIN
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DOI：
10.1152/jn.1988.59.6.1673
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发表时间：
1988-06-01
影响因子：
2.5
通讯作者：
SCHEICH, H
中科院分区：
文献类型：
--
作者：
MULLER, CM;SCHEICH, H
1.我们测试了GABA能抑制对长期准备的非麻醉鸡听端脑中213个神经元反应特征的贡献。细胞外记录获得与多管玻璃电极含有钨丝。听觉刺激包括音调，双音组合，和噪声爆发提出了自由场或通过耳机。2.神经元的反应特性进行了研究之前和期间的GABA，谷氨酸，荷包牡丹碱甲碘化（BIC），和乙酰胆碱离子电渗应用。3.在BIC应用期间，兴奋性反应被促进。除了偶尔只在BIC条件下出现的短暂关闭反应外，在单位的最佳频率下对音调刺激的时间反应模式通常不变。在任何情况下，抑制反应成分双耳提出纯音拮抗BIC。4. BIC离子导入扩大了听觉前脑结构中绝大多数神经元的等强度反应区，这些神经元位于丘脑感受器层L2的突触后。当神经元去极化到阈值水平与谷氨酸时，没有得到这种效果。5.当第二频率位于兴奋性反应区时，双音刺激会抑制神经元最佳频率的兴奋性反应。在L2层，双音抑制的频率范围较窄，BIC不能拮抗这种抑制作用。在突触后层，神经元最佳频率的三个倍频程的频率诱导了对BIC敏感的双音抑制。此外，这些神经元还显示出与L2层中所见相似的BIC不敏感抑制。6.神经元显示没有或只有一个穷人的白噪声刺激强烈响应于这种宽带刺激BIC离子电渗。7.无声调反应的神经元在应用BIC时通常显示出清晰的声调反应区。离子电渗应用乙酰胆碱，而不是谷氨酸，也引起了这样的紧张性反应。在BIC条件下观察到的响应区域内的频率的双音组合引起兴奋性反应后，从BIC应用程序完全恢复。8.在BIC离子导入过程中，大多数神经元的非单调强度响应函数被转换为单调函数。9.提出了一个基于两个独立的GABA能系统的GABA能抑制相互作用模型。（400字处截断摘要）
1. We tested the contribution of GABAergic inhibition to the response characteristics of 213 neurons in the auditory telencephalon of chronically prepared nonanesthetized chickens. Extracellular recordings were obtained with multibarrel glass electrodes containing a tungsten wire. Auditory stimuli consisted of tones, two-tone combinations, and noise bursts presented either free field or via earphones. 2. Response properties of the neurons were studied both before and during iontophoretic application of GABA, glutamate, bicuculline methiodide (BIC), and acetylcholine. 3. During BIC application excitatory responses were facilitated. With the exception of transient off-responses, which occasionally appeared only in the BIC condition, the temporal response patterns to tone stimuli at the units' best frequency usually were unaltered. In no case was an inhibitory response component to binaurally presented pure tones antagonized by BIC. 4. BIC iontophoresis enlarged the isointensity-response areas of the vast majority of neurons in the structures of the auditory forebrain lying postsynaptic to the thalamorecipient layer L2. This effect was not obtained when neurons were depolarized to perithreshold levels with glutamate. 5. Two-tone stimulation resulted in a suppression of the excitatory response to a neuron's best frequency when the second frequency lay outside the excitatory response area. In lamina L2, the frequency range inducing two-tone suppression was narrow, and the suppressive effect was not antagonized by BIC. In the postsynaptic layers, frequencies up to three octaves from the neurons' best frequency induced two-tone suppression that was sensitive to BIC. In addition, these neurons also displayed a BIC-insensitive suppression similar to the one seen in layer L2. 6. Neurons displaying no or only a poor response to white-noise stimulation strongly responded to this wide-band stimulus during BIC iontophoresis. 7. Neurons without tone responses usually displayed clear response areas to tones during BIC application. Iontophoretic application of acetylcholine, but not glutamate, also induced such tone responses. Two-tone combinations with frequencies lying within the response areas observed in the BIC condition elicited excitatory responses after full recovery from the BIC application. 8. During BIC iontophoresis nonmonotonic intensity-response functions were converted to monotonic functions in most of the neurons studied. 9. A model of GABAergic inhibitory interactions is proposed that is based on two independent GABAergic systems.(ABSTRACT TRUNCATED AT 400 WORDS)