CSF1R and Cognitive impairment: To address this hypothesis, our study employed pharmacological depletion of microglia with the colony-stimulating factor 1 receptor (CSF1R) inhibitor PLX5622 (Fig. 1) for 3-weeks while at HA in male C57BL/6J mice to assess the contribution of microglia to HA associated cognitive deficits in fear memory recall and alterations in synaptic plasticity (LTP) within the hippocampus.