A timelapse shows the development of the zebrafish nervous system over sixteen hours – not that of the spinal cord of a human embryo
Does an oft-reposted viral video show a timelapse of “16 hours of spinal cord development” in a human embryo? No, that’s not true: the video actually shows the development of a zebrafish’s nervous system recorded by researchers in Wisconsin. The video is often reposted without this information omitted, leading many online to believe it shows a human embryo.
An example of the video can be seen in this article on X (archived here) published on November 8, 2025 with a caption that read:
16 hours of spinal cord development in an embryo captured in stunning timelapse
this is a 16 hour time frame of an embryo forming its spinal cord
However, the video already appeared rotated 90 degrees in a 2018 article (archived here) titled “Light sheet imaging helps capture neural development in zebrafish” where it was described as:
The images, photographed using light-sheet microscopy, are attributed to Henry He, a scientist in Jan Huisken’s lab at the Morgridge Institute for Research, and Liz Haynes, a postdoctoral researcher in Mary Halloran’s lab at the University of Wisconsin-Madison.
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The video shows the development of a zebrafish embryo over a period of 16 hours. In a discussion with Technology Networks, Liz and Henry explain in more detail exactly what we see in the images: “The photographed embryo is a genetically modified organism expressing green fluorescent protein in a population of its sensory neurons. At the beginning of the film, the focus is on two rows of neurons in the embryo’s spinal cord (we look at its back and sides). The cell bodies of these neurons each extend two axons into the spinal cord, forming a network to communicate with the brain. then send a third axon, called the peripheral axon, which exits the spinal cord and innervates the embryo’s skin so it can detect touch. These axons grow over incredibly long distances and establish complex and beautiful architectures. At the end of the video, the tip of the embryo’s tail can be seen growing back into the focal plane of the film.
