  We consider three-loop radiative-recoil corrections to hyperfine splitting in
muonium due to insertions of one-loop polarization operator in the electron
factor. The contribution generated by electron polarization insertions is a
cubic polynomial in the large logarithm of the electron-muon mass ratio. The
leading logarithm cubed and logarithm squared terms are well known for some
time. We calculated all single-logarithmic and nonlogarithmic radiative-recoil
corrections of order $\alpha^3(m/M)E_F$ generated by the diagrams with electron
and muon polarization insertions.
