美国普林斯顿大学Andrew M. Leifer近期取得重要工作进展，他们研究创建了秀丽隐杆线虫的神经信号传播图谱。相关研究成果2023年11月1日在线发表于《自然》杂志上。

据介绍，确定神经功能如何从网络属性中产生是神经科学的一个基本问题。

为了更好地了解神经系统的结构和功能之间的关系，研究人员利用直接光遗传学激活和同步全脑钙成像，系统地测量了线虫头部 23,433 对神经元的信号传播。研究人员测量这些神经元之间信号传播的符号（兴奋性或抑制性）、强度、时间特性和因果方向，以创建功能图谱。 研究人员发现信号传播与基于解剖学的模型预测不同，主要是从解剖学上看不到的突触外信号传导导致了这种差异。

研究人员发现了许多致密核心囊泡依赖性信号传导的实例，包括在不到一秒的时间尺度上，它们会引起急性钙瞬变（通常在不存在直接有线连接但相关神经肽和受体表达的情况下）。研究人员认为，在这种情况下，突触外释放的神经肽具有与经典神经递质类似的功能，并且测量的信号传播图谱比基于解剖学的模型能更好地预测自发活动的神经动力学。

总之，这一研究表明，突触和突触外信号传导在短时间尺度上驱动神经动力学，并且诱发信号传播的测量对于解释神经功能至关重要。

附：英文原文

Title: Neural signal propagation atlas of Caenorhabditis elegans

Author: Randi, Francesco, Sharma, Anuj K., Dvali, Sophie, Leifer, Andrew M.

Issue&Volume: 2023-11-01

Abstract: Establishing how neural function emerges from network properties is a fundamental problem in neuroscience1. Here, to better understand the relationship between the structure and the function of a nervous system, we systematically measure signal propagation in 23,433 pairs of neurons across the head of the nematode Caenorhabditis elegans by direct optogenetic activation and simultaneous whole-brain calcium imaging. We measure the sign (excitatory or inhibitory), strength, temporal properties and causal direction of signal propagation between these neurons to create a functional atlas. We find that signal propagation differs from model predictions that are based on anatomy. Using mutants, we show that extrasynaptic signalling not visible from anatomy contributes to this difference. We identify many instances of dense-core-vesicle-dependent signalling, including on timescales of less than a second, that evoke acute calcium transients—often where no direct wired connection exists but where relevant neuropeptides and receptors are expressed. We propose that, in such cases, extrasynaptically released neuropeptides serve a similar function to that of classical neurotransmitters. Finally, our measured signal propagation atlas better predicts the neural dynamics of spontaneous activity than do models based on anatomy. We conclude that both synaptic and extrasynaptic signalling drive neural dynamics on short timescales, and that measurements of evoked signal propagation are crucial for interpreting neural function.

DOI: 10.1038/s41586-023-06683-4

Source: https://www.nature.com/articles/s41586-023-06683-4