CD40 and Alzheimer disease: The expression of Aß42 was significantly increased under starvation, rather than Aß40, in the cerebral cortex (Supplementary Fig. 1d); Aß42 is more likely to form aggregates than Aß40, which is an AD marker.26 Microglial activation markers, including Iba1, CD40, CD11b, and CD68,27,28 were significantly upregulated in brains under fasting (Fig. 1g, i, l, Supplementary Fig. 1), indicating a robust glial response to prolonged glucose deprivation.