  Ferromagnets are known to support spin-polarized currents that control
various spin-dependent transport phenomena useful for spintronics. On the
contrary, fully compensated antiferromagnets are expected to support only
globally spin-neutral currents. Here, we demonstrate that these globally
spin-neutral currents can represent the N\'eel spin currents, i.e. staggered
spin currents flowing through different magnetic sublattices. The N\'eel spin
currents emerge in antiferromagnets with strong intra-sublattice coupling
(hopping) and drive the spin-dependent transport phenomena such as tunneling
magnetoresistance (TMR) and spin-transfer torque (STT) in antiferromagnetic
tunnel junctions (AFMTJs). Using RuO$_{2}$ and Fe$_{4}$GeTe$_{2}$ as
representative antiferromagnets, we predict that the N\'eel spin currents with
a strong staggered spin-polarization produce a sizable field-like STT capable
of the deterministic switching of the N\'eel vector in the associated AFMTJs.
Our work uncovers the previously unexplored potential of fully compensated
antiferromagnets and paves a new route to realize the efficient writing and
reading of information for antiferromagnetic spintronics.
