PREVENTIVE AND/OR THERAPEUTIC AGENT FOR HIGHER BRAIN DYSFUNCTION

摘要

A preventive and/or therapeutic agent for higher brain dysfunctions which contains as an active ingredient a xanthane derivative represented, for example, by the following formula (I) or a pharmacologically acceptable salt thereof: (I) (II) wherein R<1>, R<2>, and R<3> are the same or different and each represents hydrogen, lower alkyl, lower alkenyl, or lower alkynyl; R<4> represents cycloalkyl, -(CH2)n-R<5>, or the formula (II) given above; and X<1> and X<2> are the same or different and each represents oxygen or sulfur.