If it is possible, it's possible in the sense that it's possible to approach lightspeed with a chemical rocket. The predominant method in modern neuroscience fo

If it is possible, it's possible in the sense that it's possible to approach lightspeed with a chemical rocket. The predominant method in modern neuroscience for recording from a large number of cells is fluorescent microscopy with genetically encoded fluorescent sensors. Whole brain imaging is now routine (at least for drosophila, and albeit probably not at cellular resolution), afaik ephys tops out at 1000s of cells. Gotta keep in mind that there are already several extant well-funded and highly motivated organizations devoted to studying the brain... and they're not doing whole-brain ephys.. they're doing advanced fluorescent microscopy