PROBLEM TO BE SOLVED: To provide a method of ameliorating a disease symptom, such as depression or anxiety, caused by " mood disturbance or related disturbance", to provide a method for searching a substance which is a medicinally active ingredient effective for treating the " mood disturbance or related disturbance", and to provide a model mammal or the like used in the method. SOLUTION: This method of ameliorating the symptom caused by mood disturbance or a related disturbance, having the step of making either of the following proteins to exist in excess in the brain of a mammal. A nonhuman mammal, etc. characterized by having been treated by the above method. Herein, the above-mentioned proteins: (a) Gm1 protein, and (b) Gm1 protein in whose amino acid sequence one or more amino acids are deleted, added or replaced and which has functions as the Gm1 protein. COPYRIGHT: (C)2007,JPO&INPIT
