https://backyardbrains.com/products/filter/Bundles

As grad students at the University of Michigan, co-founders Tim and Greg often interacted with schoolchildren during neuroscience outreach events. We often wanted to show real "spiking" activity to students, but this was impossible due to the high cost of equipment. By using off-the-shelf electronics, we designed kits that could provide insight into the inner workings of the nervous system.