FUNCTIONAL ORGANIZATION OF THE INFERIOR COLLICULUS

下丘的功能组织

• 批准号: 3216354
• 负责人: GEORGE D POLLAK
• 金额: $ 27.91万
• 依托单位: UNIVERSITY OF TEXAS AT AUSTIN
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-07-01 至 1995-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3216354
• 关键词: Chiroptera; auditory discrimination; auditory feedback; auditory nuclei; auditory pathways; auditory stimulus; bicuculline; binaural hearing; electrophysiology; gamma aminobutyrate; glutamate decarboxylase; glycine; horseradish peroxidase; inferior colliculus; neural information processing; neural inhibition; neuroanatomy; neurons; sound frequency; stimulus /response; strychnine

DESCRIPTION (Investigator's Abstract): The chief goal of these studies is to evaluate how inputs that originate from multiple lower auditory nuclei shape the response properties of collicular neurons in the mammalian auditory system. Specifically the investigators will: 1) Determine which of the cells that project to the E1 region of the colliculus, and to the 60 kHz regions of the DNLL and INLL, are GABAergic and which are glycinergic. The DNLL and INLL are the two nuclei of the lateral lemniscus that project to the 60 kHz region of the colliculus. This will be accomplished by first, in an individual bat, identifying the appropriate region in the nucleus of interest with electrophysiological recordings, and then making a focal injection of HRP. Subsequent processing will co-localize the retrogradely transported HRP with antibodies directed against glycine, GABA and glutamate decarboxylase (GAD), the synthetic enzyme for GABA. 2) Determine the monaural and binaural response properties of INLL and DNLL neurons by recording single unit activity while presenting 60 kHz tone bursts with speakers inserted into the ears. 3) Determine the functional consequences of the inhibitory inputs to the colliculus by constructing the spatial receptive fields of 60 kHz E1 neurons from their monaural and binaural response properties, which will then be compared to the changes in receptive field properties induced by iontophoretic application of bicuculling and/or strychnine. Thus, they will assess the differential roles of GABAergic and glycinergic innervation in shaping the response properties and spatial receptive fields of collicular E1 neurons, and identify the source or sources, of the GABAergic (or glycinergic) influence. Finally, by evaluating the response properties of 60 kHz neurons in DNLL and INLL and reconstructing their receptive fields, they will obtain further insights into the transformations that occur along the neuraxis, and how lower nuclei may be exerting their inhibitory influence on their targets in the 60 kHz contour of the inferior colliculus.

描述(调查人员摘要)：这些研究的主要目标是 评估来自多个低级听觉核团的输入如何 哺乳动物中丘神经元的反应特性 听觉系统。具体地说，调查人员将：1)确定 投射到丘脑E1区的细胞和投射到 DNLL和INLL的60 kHz区域是GABA能的，它们是 甘氨酸能。DNLL和INLL是外侧核的两个核心 丘脑60千赫区域的丘疹突起。这将是 首先，在单个蝙蝠中，识别 感兴趣核的适当区域与电生理 录音，然后进行HRP焦点注射。后续 处理将与逆行传输的HRP共同定位 针对甘氨酸、GABA和谷氨酸脱羧酶的抗体 (Gad)，合成GABA的酶。2)确定单声道和 单次记录INLL和DNLL神经元的双耳反应特性 在插入扬声器的情况下呈现60 kHz音突发时的单元活动 放进耳朵里。3)确定抑制的功能后果 通过构建丘脑的空间感受野向丘脑投射 60 kHzE1神经元的单耳和双耳反应特性， 然后将其与接受场属性中的变化进行比较 由离子导入应用荷包牡丹碱和/或士的宁引起。 因此，他们将评估GABA能和甘氨酸能的不同作用 影响反应特性和空间感受性的神经支配 丘脑E1神经元的视野，并确定其来源 GABA能(或甘氨酸能)的影响。最后，通过评估 DNLL和INLL中60 kHz神经元的反应特性及重建 他们的接受领域，他们将获得对 沿着神经轴发生的变化，以及细胞核可能有多低 在60 kHz等值线上对目标施加抑制影响 下丘的位置。