Auditory processing of descending neurons in the prothorax of a bush-cricket

灌木蟋蟀前胸下降神经元的听觉处理

• 批准号: 437373126
• 负责人: Professor Dr. Andreas Stumpner
• 金额: --
• 依托单位: Abteilung Zelluläre Neurobiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/437373126?language=en
• 关键词: Auditory; processing; descending; neurons; prothorax

Auditory processing and song recognition in bush-crickets has gained increasing interest during the last twenty years. The species Ancistrura nigrovittata has been studied from their acoustic behavior (the male sings, the female replies, both perform phonotaxis) to the neuronal basis of that behavior on the level of sensory neurons and interneurons on various levels. A. nigrovittata is of special interest due to three features: (i) males and females produce songs with different carrier frequencies, (ii) males and females produce songs of different temporal patterns and (iii) the male song has two components, from which one serves as identifier for the species and the second as trigger for the short, reflex-like female reply. Several local prothoracic neurons, ascending neurons to the brain and brain neurons have been studied so far. One group of auditory neurons with a descending axon from the prothorax to posterior ganglia (DN) has been widely ignored in A. nigrovittata due to its small processes in the prothoracic ganglion making intracellular recordings difficult. A previous study on local neurons (DUM) has shown that recording from the soma is a promising alternative in such a situation. Preliminary studies have demonstrated, that it is possible to record and stain DN with success from their soma and have suggested the existence of at least seven different DN types on each side. The purpose of the project is to characterize descending neurons by their morphology and responses to acoustic stimuli. This should identify potentially relevant neurons for song recognition. Among these might be a neuron tuned to the male song, which might elicit the female reply song, which is produced reflex like by the mesothoracic wings and is too fast to loop via the brain. Others obviously respond to low frequencies and vibration, as described for other bush-cricket species. It would be interesting to know, whether these respond selectively to the conspecific song pattern and, therefore, might be relevant for close distance communication. Even others seem to respond well to ultrasound – their specific properties might help to understand their potential role. Experiments with blocking inhibition should demonstrate, whether sharpening of tuning occurs as described for other auditory neurons as well, but not for descending neurons. This is suggested by the observation of IPSP-like negative deflections of the membrane potential.

在过去的二十年里，丛林蟋蟀的听觉处理和歌曲识别得到了越来越多的关注。在不同水平的感觉神经元和中间神经元水平上，从发声行为(雄性鸣叫，雌性应答，两者都执行趋声)到该行为的神经元基础上，研究了黑腹鱼的声学行为。黑斑潜蝇具有三个特征：(1)雄性和雌性产生具有不同载频的歌声；(2)雄性和雌性产生不同时间模式的歌声；(3)雄性歌声有两个成分，其中一个成分用作物种的识别符，另一个成分作为简短的、反射式的雌性应答的触发器。到目前为止，人们已经研究了几个局部的前胸段神经元、向脑的上行神经元和脑神经元。在黑斑潜蝇中，有一组听神经元的轴突是从前胸到后神经节的下行轴突，由于其突起较小，细胞内记录困难，因此被广泛忽视。以前对局部神经元(DUM)的研究表明，在这种情况下，从体细胞进行记录是一种很有前途的选择。初步研究表明，从它们的体细胞中成功地记录和染色糖尿病肾病是可能的，并表明每侧至少存在七种不同的糖尿病肾病类型。该项目的目的是通过形态和对声刺激的反应来描述下行神经元的特征。这应该会识别出与歌曲识别潜在相关的神经元。其中可能有一个神经元调谐到男性的歌声，这可能会引发女性的应答歌曲，这是由间胸膜翅膀产生的反射，太快了，无法通过大脑循环。其他物种显然会对低频和振动做出反应，就像其他灌木-蟋蟀物种所描述的那样。这将是有趣的，知道这些是否有选择地回应同种的歌唱模式，因此，可能与近距离交流有关。即使是其他人也似乎对超声波反应良好--他们的特殊性质可能有助于理解他们的潜在作用。阻断抑制的实验应该证明，调谐的锐化是否也像对其他听觉神经元所描述的那样发生，但不是对下行神经元。观察到膜电位出现IPSP样的负偏转，提示了这一点。