Representative images of CD68 immunofluorescence staining of cortex samples form controls and homozygous Townes after exposures to normoxia (room air) and chronic intermittent hypoxia (8% fraction of inspired oxygen)/reoxygenation for seven days. We found that during basal conditions (exposure to normoxia/room air, A and B) homozygous Townes had similar percentage of CD 68 positive cells (intense red dots, p=0.801) and similar CD68+ staining/nucleus area ratio (p=0.693) compared to controls, C, D, E, F. The effect of chronic intermittent hypoxia/reoxygenation exposures on the percentage of CD68-positive cells varied according to genotype as there was a genotype by exposure interaction (p=0.026, E). Specifically, hypoxia-exposed homozygotes, had a higher percentage of CD68 positive cells compared to normoxia-exposed animals (p=0.002). In contrast, hypoxia- and normoxia-exposed controls had similar percentage of CD68-positive cells (p=0.823). F. Overall, there was a significant effect of repeated hypoxia/reoxygenation exposures in that both controls and homozygotes had greater CD68+ staining/nucleus area ratio compared to normoxia-exposed animals (p=0.006, for effect of exposure). N=4-7 per genotype (control, homozygote) and exposure (normoxia, hypoxia).