Can the negative glow plasma have a negative charge?

The classical problem of the gas discharge physics is discussed: what is the sign of charge density in the negative glow region of a glow discharge. The question about the sign of the net charge in NG is important to improve and refine the classical picture of the plasma parameters distribution for a wide class of glow discharges (from the usual glow discharges, to the widely used in scientific researches and applications hollow cathode discharges consisting exclusively of the cathode sheath and the negative glow plasma).