The source: https://bbp.epfl.ch/thalamoreticular-portal A sample NWB that takes a lot of time to load: [JY180406_A_1](https://bbp.epfl.ch/nexus/web/public/thalamus/resources/https%3A%2F%2Fbbp.epfl.ch%2Fneurosciencegraph%2Fdata%2Ftraces%2F93fce18a-2deb-43f9-81db-6a341356260b) Investigate the issue. I suspect it is because of some expensive operation we perform per-frame.