Combined CSF1R Inhibition and Sensory Gamma Stimulation Provide Protective Effects in a Mouse Model of Alzheimers Disease

The CSF1R inhibitor PLX3397, an FDA-approved treatment for a rare cancer, has been shown to reduce microglia count, lower inflammation, and increase synaptic markers in mouse models of Alzheimers disease (AD). However, the effects of PLX3397 on neural function in AD remain largely unknown. Here, we characterized the effects of PLX3397 treatment in 5xFAD mice. While PLX3397 increased synaptic density, it reduced the percentage of neurons phase-locked to gamma oscillations. This neural decoupling was closely associated with gene expression changes related to synapse organization. We investigated whether Gamma ENtrainment Using Sensory (GENUS) stimulation could counterbalance the neural circuit alterations induced by PLX3397. GENUS + PLX3397 restored gamma phase-locking, reshaped gene expression signatures, and improved learning and memory better than either treatment alone in 5xFAD mice. These findings suggest that CSF1R inhibitors like PLX3397 may benefit from a multimodal approach combining microglial targeting with non-invasive sensory stimulation to support neural physiology and improve cognitive function in AD.