Alterations of central serotoninergic and dopaminergic neurotransmission in rats chronically treated

A data entry keyboard includes a key array overlying a switching assembly so that a switch is operated when a corresponding key is depressed. The key array is made by forming a transparent plastic sheet into a blank having a number of upwardly extending key projections and having a downwardly extending switch actuating projection adjacent each key projection. Indicia are applied to the underside of the sheet so the indicia are both visible and protected from wear. A back coat overlies the indicia on the underside of the sheet. The blank is cut to remove material surrounding each key and to define an integral hinge permitting deflection of each key and its associated switch actuating projection. The key array is assembled with the switching assembly, and a mask overlies the key array and permits access to individual keys.