Institut für Neuro- und Verhaltensbiologie, Universität Münster, Badestreet 9, 48149, Münster, Germany.
LIMES Institute, University of Bonn, Carl Troll Street 31, 53115, Bonn, Germany.
Nat Commun. 2020 Sep 8;11(1):4491. doi: 10.1038/s41467-020-18291-1.
The functionality of the nervous system requires transmission of information along axons with high speed and precision. Conductance velocity depends on axonal diameter whereas signaling precision requires a block of electrical crosstalk between axons, known as ephaptic coupling. Here, we use the peripheral nervous system of Drosophila larvae to determine how glia regulates axonal properties. We show that wrapping glial differentiation depends on gap junctions and FGF-signaling. Abnormal glial differentiation affects axonal diameter and conductance velocity and causes mild behavioral phenotypes that can be rescued by a sphingosine-rich diet. Ablation of wrapping glia does not further impair axonal diameter and conductance velocity but causes a prominent locomotion phenotype that cannot be rescued by sphingosine. Moreover, optogenetically evoked locomotor patterns do not depend on conductance speed but require the presence of wrapping glial processes. In conclusion, our data indicate that wrapping glia modulates both speed and precision of neuronal signaling.
神经系统的功能需要沿着轴突以高速和高精度传输信息。电导率取决于轴突的直径，而信号精度则需要轴突之间的电串扰阻断，即电突触耦合。在这里，我们利用果蝇幼虫的外周神经系统来确定胶质细胞如何调节轴突特性。我们发现，包绕胶质细胞的分化取决于缝隙连接和 FGF 信号。异常的胶质细胞分化会影响轴突的直径和电导率速度，并导致轻微的行为表型，而富含神经酰胺的饮食可以挽救这些表型。包绕胶质细胞的消融不会进一步损害轴突的直径和电导率速度，但会导致明显的运动表型，而神经酰胺无法挽救这种表型。此外，光遗传学引发的运动模式不依赖于电导率速度，但需要存在包绕胶质细胞的突起。总之，我们的数据表明，包绕胶质细胞调节神经元信号的速度和精度。
