A method of forming an apparatus includes forming pillar structures extending vertically through a first isolation material, forming conductive lines operatively coupled to the pillar structures, forming dielectric structures overlying the conductive lines, and forming air gaps between neighboring conductive lines. The air gaps are laterally adjacent to the conductive lines with a portion of the air gaps extending above a plane of an upper surface of the laterally adjacent conductive lines and a portion of the air gaps extending below a plane of a lower surface of the laterally adjacent conductive lines. Apparatuses, memory devices, methods of forming a memory device, and electronic systems are also disclosed.