arm(s) of elevated plus maze apparatus enclosed arm of elevated plus maze apparatus 2012-07-24T05:12:07Z JSmith MMO:0000265 One or both of the arms of an elevated plus maze apparatus which are bounded on two or three sides by walls, forming an observable enclosure. An elevated plus maze is an experimental apparatus which consists of four arms, usually two enclosed and two open, in the shape of a plus (+) upon which the test animal can walk. The maze is elevated a set distance, for example 40 to 60 cm, above the floor or platform upon which the apparatus sits. closed arm of elevated plus maze apparatus enclosed arm of EPM measurement_method_ontology