What connections (e.g. between gate, drain, source, body, and surrounding circuit) are implied by this MOSFET symbol with a line through it (M3)? For comparison, here is another NMOS transistor from the same paper without a line through it (M4).
It's common in IC schematics to route a connection through the base/gate of a transistor -- that means "connect to this base/gate and keep going" in a compact and efficient way, vs. having to tap off a wire and route around the transistor symbol. No body connections are implied by the through-routing, by the way.