在FM回声定位蝙蝠的听觉大脑干中,对回声延迟的微秒级编码
Andrea Megela Simmons1,2,3, Michaela Warnecke2, James A Simmons2,3
1Department of Cognitive and Psychological Sciences, Brown University, Providence, Rhode Island, United States.
Journal of neurophysiology
|November 21, 2024
概括
大棕色蝙蝠通过神经群体反应实现精确的回声延迟检测. 大脑干核中的延迟动接近蝙蝠的显著感知敏度.
科学领域:
- 神经科学是一个神经科学.
- 听觉神经科学 听觉神经科学
- 感官系统 感官系统
背景情况:
- 声波定位蝙蝠,如大棕色蝙蝠 (Eptesicus fuscus),在检测超声波回声延迟方面表现出非凡的精度,达到1微秒或更低的灵敏度.
- 在回声延迟检测中的这种超敏度背后的神经机制在很大程度上仍然是未知的.
- 了解这些机制对于破译感官知觉的神经基础至关重要.
研究的目的:
- 为了研究神经延迟记录的精度,特别是延迟动,在蝙蝠听觉系统内的群体反应中.
- 为了确定神经群体的动是否可以解释蝙蝠的异常回声延迟敏度.
- 为了比较不同脑干听力核中的潜伏动.
主要方法:
- 从麻醉的大棕色蝙蝠的耳细胞核和下层结膜中记录了局部场势.
- 测量了对模拟的回声定位声音的反应,包括频率调制的扫描和四个回声级联在不同延迟.
- 延迟动被量化为神经对初始声音和随后的回声的反应.
主要成果:
- 发现初始声音的平均延迟动在耳核中大约为51μs,在较低的中大约为56μs.
- 连续回声的延迟动增加了,平均分别为125微秒和111微秒.
- 这些人口水平的延迟动值明显低于单个神经元通常报告的值,接近蝙蝠的心理物理敏度.
结论:
- 神经群体在耳细胞核和下结核中的延迟动足够精确,有可能解释大棕色蝙蝠在回声延迟检测中的高敏度.
- 这些发现表明,同步的人口活动,而不是单个神经元的精度,可能是这种非凡的感知壮举的基础.
- 需要进一步的系统级研究来充分阐明参与蝙蝠回声定位感知的神经计算.
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