The molecular version of semitrucks are proteins aptly named motor proteins, that can walk along microtubules, dragging sometimes huge cargoes, like organelles, behind them.
And this led him in combination with scientist Stuart Hameroff to explore the Less common position that consciousness is connected to quantum stuff in the brain, in what we call the microtubules.
But in Alzheimer's disease, Tau is modified, causing it to dissociate from the microtubules, adopt an abnormal shape and move from the axon to the cell body.