Ischemic preconditioning is an emerging research technique used to study ischemic injury that may lead to new treatments as well as stroke prevention methods for humans. Ischemic stroke occurs when blood flow is occluded to the brain (Stroke Center). Ischemic preconditioning is a technique used in mice by transiently occluding blood flow into the middle cerebral artery; this has been shown to be neuroprotective and reduce infarct volume in brain tissue (Weinstein et al., 2010). More specifically, ischemic preconditioning leads to microglia proliferation (Weinstein et al., 2010). Currently, there is conflicting research on the source of microglia proliferation. Some research demonstrates microglia proliferate from a distinct progenitor population (Elmore el al., 2014); whereas, other research argues microglia proliferate from other adult microglia (Huang et al., 2018). This current study attempts to address this dilemma by using ischemic preconditioning to elicit microglia proliferation. My study was twofold: first, mice were tested for motor cortex deficiencies following ischemic preconditioning to ensure males and females responded the same to surgery. Second, this study aimed elucidate the source of microglia proliferation using a fate-mapping approach. This study used mice that underwent ischemic preconditioning and used immunohistochemistry and microscopy in order to characterize the source of microglia proliferation. We found microglia proliferate from a combination of microglia progenitor cells and other adult microglia. Additionally, we found a significant increase in female motor cortex deficiencies as compared to male. This study demonstrates a need for further investigation of sex differences in ischemic preconditioning and contributes evidence of the source of microglia proliferation after preconditioning, allowing researchers to further investigate the neuroprotective effects of ischemic preconditioning on stroke.