I was thinking this too lately when I heard someone talk about brain research on chimpanzees. The chimps are total slaves with no choice in what happens, which is horrible. Would it not be better for humans to be able to volunteer? I guess we would need to keep money out of the equation or it could get unseemly fast.
Uhm... all kinds of animals actually, but you need ethics approval if you use vertebrates. And I don't think you will find non-crazy volunteers for the invasive experiments...
I took neuroscience courses - and a lot of what I learned was made possible by such experiments, so I'm not against them. However, the cost for the animals that get selected is high. You can't do that with humans, only the most benign experiments. But many experiments involves cutting open the head. inserting electrodes at the very least, sometimes you want to see the brain too - there are things you can do, like two-photon microscopy (example: https://www.neurotar.com/contract-research/two-photon-imagin... -- you have to expose the brain), or inject dyes, and other options).
A possible setup (for invasive experiments) is that the animal is drugged, the brain exposed, electrodes inserted, the head fixated. Now you can, stimulate the retina, or the ears, or whiskers, and follow what happens in the living brain. Here is an example for what you get from such an experiment: http://www.jneurosci.org/content/34/29/9537
> Mice were head-fixed using a titanium head postimplant... For implantation, mice were anesthetized with isoflurane..., and maintained at 37°C body temperature on a thermal blanket (Harvard Apparatus). Following a local injection of Marcaine (50 μl), the scalp and periosteum over the dorsal surface of the skull were removed. The skull was then coated with a thin layer of cyanoacrylate adhesive (Krazy Glue, Elmer's Products).... (etc.)
"And I don't think you will find non-crazy volunteers for the invasive experiments"
Take a look into the "wirehead" culture. There are people right now applying electric currents to their brains because they believe it enhances them in various ways.
Many are sane, unless you define them as insane solely on the basis of being wireheads.
It's a waste and a tragedy that we can't monitor their outcomes in a scientifically valid way. Not to mention chilling their self-reporting with legal uncertainty.
