Astroglia and brain metabolism : focus on energy and neurotransmitter amino acid homeostasis / Arne Schousboe, Anne B. Walls, Lasse K. Bak, and Helle S. Waagepetersen.

Format:

Book

Author/Creator:

Schousboe, Arne, author.

Walls, Anne B., author.

Bak, Lasse K., author.

Waagepetersen, Helle S., author.

Series:

Colloquium digital library of life sciences.

Colloquium series on neuroglia in biology and medicine ; 2375-9917 # 7.

Colloquium series on neuroglia in biology and medicine, 2375-9917 ; # 7

Language:

English

Subjects (All):

Astrocytes.

Brain--Metabolism.

Brain.

Amino acids--Metabolism.

Amino acids.

Brain--metabolism.

Amino Acids--metabolism.

Medical Subjects:

Astrocytes.

Brain--metabolism.

Amino Acids--metabolism.

Physical Description:

1 online resource (76 p.)

Place of Publication:

San Rafael, California (1537 Fourth Street, San Rafael, CA 94901 USA) : Morgan & Claypool, 2015.

Language Note:

English

Summary:

The present outline of astrocytic metabolic pathways involved in glucose and amino acid metabolism provides detailed information about the enzymatic pathways involved, as well as a description of the basic properties of the enzymes including regulatory mechanisms. Hence, the glycolytic pathway and glycogen metabolism are outlined, followed by a detailed account of pyruvate oxidation and its role as a substrate for the tricarboxylic acid (TCA) cycle. Moreover, a detailed description of the main enzymes involved in glutamate metabolism is provided and the role of the glutamate-glutamine cycle is explained. Since this text is primarily covering astrocytic metabolism, an emphasis has been placed on a discussion of the significance of the astrocyte specific enzymes pyruvate carboxylase and glutamine synthetase, which enable these cells to perform a net synthesis of glutamine, the precursor for synthesis of glutamate and ã-aminobutyrate (GABA), the main neurotransmitters of the brain. With this, we have underlined the fundamental importance of astrocytic metabolism for neuronal function with a particular emphasis on the fact that, without continuous support from the astrocytic partners in synaptic function, glutamatergic and GABAergic neurotransmission would not be possible. It is thought provoking that these neurotransmission processes, which account for the vast majority of synaptic activity in the brain, have been made totally dependent on astrocytic metabolic support, particularly with regard to replenishment of the respective neurotransmitters.

Contents:

1. Introduction to glia

2. Metabolism of glia

2.1 Glucose and glycogen metabolism

2.1.1 Glycolysis

2.1.2 Glycogen synthesis and glycogenolysis

2.2 Pentose phosphate shunt

2.3 The functional importance of the glycogen-shunt

2.4 Lactate production and shuttling

2.4.1 Functional importance of LDH isozymes for lactate shuttling

2.5 Pyruvate oxidation and the tricarboxylic acid (TCA) cycle

2.5.1 Compartmentation of astrocytic pyruvate and TCA cycle metabolism

2.5.2 Regulatory roles of calcium in the TCA cycle

2.6 Pyruvate recycling and lactate production from TCA cycle intermediates

2.7 Pyruvate carboxylation

2.7.1 Pyruvate carboxylation and glutamine biosynthesis

2.7.2 Pyruvate carboxylation and synthesis of TCA cycle intermediates

2.8 Glutamate and glutamine metabolism and homeostasis: the glutamate-glutamine cycle

2.8.1 Enzymes

2.8.2 Glutamate transporters

2.8.3 Glutamine transporters

2.8.4 Glutamate as an energy substrate

2.8.5 Glutamate as a neurotoxin

2.8.6 Ammonia homeostasis and hepatic encephalopathy

2.9 GABA metabolism and homeostasis

2.9.1 Enzymes

2.9.2 GABA transporters and seizure control

3. Concluding remarks

References

Author biographies.

Notes:

Part of: Colloquium digital library of life sciences.

Includes bibliographical references (pages 37-63).

Title from PDF title page (viewed on August 19, 2015).

Cited in:

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ISBN:

1-61504-713-1

OCLC:

916951570