FIG. 4.

Microglial activation after traumatic brain injury (TBI) is inhibited by intranasal administration of nicotinamide adenine dinucleotide (NAD⁺). (A) The sections harvested at 1 or 7 days after TBI were immunostained with CD11b. Morphological changes and intensity of microglial immunostaining was prominent after TBI. TBI increased microglial activation in the hippocampal CA3 area 1 day after the insult, and substantially increased it 7 days after the insult. Intranasal administration of NAD⁺ (TBI-NAD) reduced microglial activation in the hippocampal area (scale bar=50 μm). (B) Quantification of microglial activation was performed on the hippocampal CA3 pyramidal area. Microglial activation is quantified based on morphological changes and intensity of CD11b staining. Data are mean±standard error of the mean; n=3–6 for each group; *p<0.05 compared with the saline-treated group. Color image is available online at www.liebertonline.com/neu