Next, we tested anhedonia, another trait of depression-like phenotype, with the sucrose preference test and found that aged mice showed significantly decreased preference for the sucrose solution compared to young (aged, 73.2 ± 4.5; young, 87.9 ± 1.2), but GDF11 treatment in aged mice restored this preference (GDF11, 86.9 ± 1.2; aged, 73.2 ± 4.5; Fig. 1g). This evidence concerns the gene GDF11 and depressive symptom measurement.