Behavioral pattern separation is the ability to distinguish between two very similar situations or stimuli. Dependent upon hippocampal function (especially the dentate gyrus, DG), this ability worsens with age and certain psychological/neurological disorders. It is critical to understand the neural substrates required for behavioral pattern separation in order to treat these individuals. Previous rodent studies propose that behavioral pattern separation requires sparse neuronal activity of granule cells. In short, interneuron somatostatin (SST) cells target DG granule cells directly or indirectly via other interneurons. Therefore, when SST cells are inhibited, the resulting disinhibition leads to overall excitation of granule cells and context discrimination is impaired. Still, a lot remains unknown. Study of interneuron SST cells more specifically confirms their role in context discrimination. However, as of yet, this research does not assess behavioral pattern separation with various memory loads. Here, we hypothesize that SST cells will impair behavioral pattern separation when inhibited. In our investigation, we used chemogenetics to inhibit SST cells in the DG. 4-month-old mature SST-Cre male mice (n=17) underwent bilateral viral infusion with Gi-coupled Cre-dependent human muscarinic receptor (hM4Di-mCherry, inhibitory) or control virus (mCherry). Then, 3 weeks post-infusion, we tested behavioral pattern separation with a spontaneous location recognition (SLR) task, consisting of a 10 minute sampling phase and a 5 minute testing phase. On test day, Compound 21 (C21, i.p.) was administered 30 minutes prior to the sampling phase. In our control group, we found similar performance in discrimination learning with various memory loads. More interestingly, while we did not find differences in discrimination of dissimilar and extremely similar object location between control and inhibition groups, DG inhibition did impair discrimination with similar object location. In the future, interneuron SST cells could be targeted to help individuals whose behavioral pattern separation abilities have been damaged by aging or psychological/neurological disorders.