There's a class of cells, a fairly small cell, an inhibitory cell, that quiets its neighbors.

So for example, lets sort of consider that basket cell I told you about earlier the one that's atrophied in schizophrenia and the one that is inhibitory.

And if you actually look in their brains, you see that they're flooded with these neurotransmitters that are really good at inducing learning and plasticity, and the inhibitory parts haven't come on yet.