Astrocytes system

Fig. 8.1 Glucose metabolism in coupled neuron and astrocyte system. ATP is produced via oxidative energy metabolism (glycolysis, TCA cycle and oxidative phosphorylation) in neurons and in astrocytes. Na+ entry during electrical activity initiates increased oxidative energy metabolism within neurons. The activation of neuronal Na+-K+ ATPase in the plasma membrane leads to reduced levels of ATP, which rapidly activates glycolysis. This process requires an elevated glucose level, which is transported via the neuronal glucose transporter (GT). The generated ATP can restore the Na+/K+ balance via Na+-K+ ATPase. The rapid increase of glycolysis results in increased NADH/NAD+ and increased cytoplasmic pyruvate. In astrocytes,...

Category of glial cells in the vertebrate central nervous system with long radial processes. Astrocytes provide structural support to neive cells and help to control their chemical and ionic extracellular environment. 

Non-neuronal cells (including astrocytes, mechan-osensory hair cells, macrophages, keratinocytes, endothelial cells of the vascular system, muscle cells, lymphocytes, intestinal epithelial cells and various cell-types of the lungs)... 

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Cavenee WK, Fumari FB, Nagane M, Huang H-JS, Newcomb EW, Signer DD, Weller M, Berens ME, Plate KH, Israel MA, Noble MD, Kleihues P (2000) Astrocytic Tumours. In Kleihues P, Cavenee WK (eds) World Health Organization classification of tumours tumours of the central nervous system. lARC Press, Lyon, pp 9-54... 

From the overall data, it is becoming inaeasingly apparent that astrocytes, by releasing chemical transmitters (the so called gliotrasmitters , Bezzi and Volterra 2001), now appears to be aitically implicated in rapid conununication systems in the brain. 

In view of our results and the strategic localization of CXCL12 and its receptor (discussed in Sect. 12.1.1), it is intriguing to speculate that the CXCL12/CXCR4 system might be involved in a fast bidirectional communication system between astrocytes and neurons. 

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Sheng WS, Hu S, Gekker G, Zhu S, Peterson PK, Chao CC (1997) Immunomodulatory role of opioids in the central nervous system. Arch Immunol Ther Exp (Warsz) 45 359-366 Sheng WS, Hu S, Lokensgard JR, Peterson PK (2003) U50, 488 inhibits HIV-1 Tat-induced monocyte chemoattractant protein-1 (CCL2) production by human astrocytes. Biochem Pharmacol 65 9-14... 

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