Figure 4: The role of glucose in brain functioning. Glucose metabolism regulates the vagal nerve and neuroendocrine signals and provides energy for neurotransmission. Histological images of the pancreas, duodenum, liver, and large intestine (Hematoxylin and eosin staining, scale bars: 100 μm and 200 μm). A: Pancreas tissue, B: Stomach tissue, C: Livertissue, D: Large intestine. Glu: Glutamate, GluR: Glutamatergic receptors, Gln: Glutamin, EAAT: excitatory amino acid transporters, GLUT1: glucose transporter 1, (Modified from ,).