The invention concerns the use of PDE2 inhibitors for treating disorders of the central and peripheral nervous system, a method for therapeutic treatment by administering to an animal said inhibitors. A pair of upper and lower edge extending members are positioned in retaining fashion over corresponding upper and lower edges of the insert sheet and which receiving threaded compression screws with turn knobs through apertures defined in the ends of the elongate members and which align with threaded apertures associated with upper and lower edge locations of the frame. Each element has a first side edge, a first end edge, a main opening large enough for a rope extending in a first dimension through it, and a slot extending between the first side edge and the opening, the slot allowing a rope to pass through the slot into the opening.