INVOLVEMENT OF GABA IN ACOUSTICALLY-EVOKED INHIBITION IN INFERIOR COLLICULUS NEURONS
INVOLVEMENT OF GABA IN ACOUSTICALLY-EVOKED INHIBITION IN INFERIOR COLLICULUS NEURONS
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DOI：
10.1016/0378-5955(91)90200-s
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发表时间：
1991-03-01
期刊：
影响因子：
2.8
通讯作者：
CASPARY, DM
中科院分区：
文献类型：
--
作者：
FAINGOLD, CL;BOERSMA, CA;CASPARY, DM
大多数关于GABA在下丘中央核（ICc）中作为抑制性神经递质的标准已经得到满足，但GABA在ICc中的声学编码作用尚未确定。 本研究探讨了这个问题，通过评估的影响，改变GABA受体的潜在形式的声诱发抑制ICc神经元的活性剂的离子电渗应用。 GABA（A）拮抗剂荷包牡丹碱的应用，选择性地阻止了在ICc神经元的非单调率-强度功能期间观察到的高强度放电减少。 双耳抑制被荷包牡丹碱选择性地阻断，并被哌啶甲酸增加。 应用GABA，nipecotic酸（GABA摄取抑制剂）和苯二氮卓类（泮），这增强了GABA的作用，增加了同侧抑制和响应暂停的持续时间和强度，而荷包牡丹碱阻断了这些听觉诱发的抑制事件。 偏置抑制增加了哌啶甲酸的应用和减少荷包牡丹碱的外观的偏移峰。 目前的数据支持一个重要的作用，GABA作为一种神经递质，介导，部分，非单调性，双耳抑制，响应暂停和抵消抑制ICc神经元。 这些GABA介导的抑制现象的改变可能会发生在听觉功能障碍与老化和听源性癫痫发作。
Most criteria for establishing GABA as an inhibitory neurotransmitter in the central nucleus of inferior colliculus (ICc) have been satisfied, but the role of GABA in acoustic coding in ICc is not established. The present study examined this issue by evaluating the effects of iontophoretic application of agents that alter activity at GABA receptors on potential forms of acoustically-evoked inhibition in ICc neurons. Application of the GABA(A) antagonist, bicuculline, selectively blocked the firing reduction at high intensities observed during non-monotonic rate-intensity functions in ICc neurons. Binaural inhibition was selectively blocked by bicuculline and increased by nipecotic acid. Application of GABA, nipecotic acid (GABA uptake inhibitor) and a benzodiazepine (flurazepam), which enhances the action of GABA, increased the duration and intensity of ipsilateral inhibition and response pause, while bicuculline blocked these acoustically-evoked inhibitory events. Offset inhibition was increased by nipecotic acid application and reduced by bicuculline with the appearance of an offset peak. The present data support an important role for GABA as a neurotransmitter, mediating, in part, non-monotonicity, binaural inhibition, response pause and offset inhibition in ICc neurons. Alterations of these GABA-mediated inhibitory phenomena may occur in auditory dysfunctions observed with aging and audiogenic seizures.