Contributors

Luigi Francesco Agnati, Department of Human Physiology, University of Modena, Modena, Italy James W. Anderson, Department of Physiology, Queen's University, Kingston, Ontario, Canada Mircea Bancila, Laboratoire de Neurobiologie de Signaux Intercellulaires, Institut des Neurosciences, Universit Pierre et Marie Curie, Paris, France Giorgio Carmignoto, Department of Experimental Biomedical Sciences, University of Padova, Padova, Italy Sophie Chabot, Department of Oncology and Clinical...

Neuronal Energy Deprivation

There are three major conditions, or encephalopathies, that could lead to neuronal energy deprivation Hypoglycemia, or glucose deficiency in the blood anoxia (hypoxia), or O2 deficiency in the inspired air and ischemia, or deficiency in blood supply, which, in essence, combines the first two deficiencies. All three encephalopathies are characterized by an inadequate supply of one of the two major energy substrates, or both. Since glucose and O2 are the two major energy substrates of the brain,...

Ion Homeostasis And Neurological Disease

Substantial progress has been made in the understanding of the pathophysiology and mechanisms involved in the attenuation of brain homeostasis. In many diseases that Fig. 6. (previous page) Immunocytochemical (ICC) localization of ERG channel protein in hippocampal astrocytes. Left panel Electron microscopy of biocytin-filled astrocytes (A and C) is shown for comparison with ICC of ERG (C1) channel protein in astrocytes (B and D). Note the similar morphological features of hippocampal...

Neuronal Energy Demands Substrates And Energy Generation

Descriptions of cerebral energy requirements found in the literature may confuse many readers. On one hand, Hawkins (1) states that, Although nervous tissue does not participate in processes that require large amounts of energy, such as mechanical work, osmotic work, or extensive biosynthesis, it has almost as high a rate of oxidative metabolism as some tissues that do. On the other, Clarke and Sokoloff (2) assert that, Although it is sometimes stated that the brain is unique among tissues in...

And Energy Metabolism In The Brain

Neuronale Anaerobic Glycolysis

The assumption that activation of brain tissue is dependent on energy supplied by oxidative metabolism of glucose was challenged over a decade ago (4,5). As has been seen from the first subheading, magnetic resonance imaging measurements of glucose consumption and concomitant calculations of O2 consumption from blood flow measurements indicated a possible mismatch between the two, upon activation of the brain. More recent studies (45,46) claim that no such mismatch exists, and that the initial...

References

Hawkins, R. (1985) Cerebral energy metabolism, in Cerebral Energy Metabolism and Metabolic Encephalopathy (McCandless, D. W., ed.), Plenum, New York, pp. 3-23. 2. Clarke, D. D. and Sokoloff, L. (1994) Circulation and energy metabolism of the brain, in Basic Neurochemistry (Siegle, G. J., Agranoff, B. W., Albers, R. W., and Molinoff, P. B., eds.), Raven, New York, pp. 645-680. 3. Cahill, G. F., Jr. and Aoki, T. T. (1988) Alternate fuel utilization by brain, in Cerebral Metabolism and Neural...

Serotonin System

5-HT neurons (54-56) have long been known to innervate the brain with axon varicosities (terminals) that often lack morphologically defined synaptic specializations (5). For example, in rat neocortex, neostriatum, and hippocampus, the synaptic incidence of 5-HT terminals has been shown to be in the order of 20-45 , depending on the region and or the layer considered (57). In the cerebral cortex, both junctional and nonjunctional 5-HT varicosities have been observed along the same axons (58),...