Label-free three-photon imaging of intact human cerebral organoids: Tracking early events in brain development and deficits in Rett Syndrome

Human cerebral organoids are unique in their development of progenitor-rich zones akin to ventricular zones from which neuronal progenitors differentiate and migrate radially. Analyses of cerebral organoids thus far have been performed in sectioned tissue or in superficial layers due to their high scattering properties. Here, we demonstrate label-free three-photon imaging of whole, uncleared intact organoids (~2 mm depth) to assess early events of early human brain development. Optimizing a custom-made three-photon microscope to image intact cerebral organoids generated from Rett Syndrome patients, we show defects in the ventricular zone volumetric structure of mutant organoids compared to isogenic control organoids. Long-term imaging of live organoids reveals that shorter migration distances and slower migration speeds of mutant radially migrating neurons are associated with more tortuous trajectories. Our label-free imaging system constitutes a particularly useful platform for tracking normal and abnormal development in individual organoids, as well as for screening therapeutic molecules via intact organoid imaging.ImageJ or Fiji is required to open the data set.Funding provided by: HHS | NIH | National Institute of Biomedical Imaging and Bioengineering (NIBIB)Award Number: K99EB027706Funding provided by: HHS | NIH | National Institute of Mental Health (NIMH)Award Number: mh085802Funding provided by: HHS | NIH | National Institute of Mental Health (NIMH)Award Number: ns090473Funding provided by: HHS | NIH | National Institute of Biomedical Imaging and Bioengineering (NIBIB)Award Number: P41-EB015871Funding provided by: National Science Foundation (NSF)Award Number: EF1451125Funding provided by: HHS | NIH | National Institute of Neurological Disorders and Stroke (NINDS)Award Number: R35NS097370Funding provided by: JPB Foundation (JPBF)Award Number:This dataset was collected by imaging intact cerebral organoids by performing point scanning label-free three-photon microscopy. We collected individual 2d images and then move to another z-plane so that we can acquire volumetric images in these organoids