1. Metabolism in Nervous Tissue
5/20/2018
Metabolism in Nervous Tissue
Glycolysis
Glycogenolysis (stress)
-oxidation (ketone bodies)
Krebs (tricarboxylic acid) cycle
Branched-chain amino acids
Electron transport chain
Eric Niederhoffer
SIU-SOM

2. Pathways Overview Production of ATP G6P Glucose Pyruvate Ketone bodies
5/20/2018
Pathways Overview
Glycolysis
G6P
Glucose
Pyruvate
Ketone bodies
Fatty acids
b-oxidation
Glycogen
Glycogenolysis
Lactate
(glial)
Lactate
No O2
Acetyl-CoA
Krebs
cycle
Electron
Transport
Chain
G6P: glucose-6-phosphate BCAA: branched-chain amino acids
Ile: isoleucine & Val: valine (enter as succinyl CoA); Leu: leucine (enters as acetyl CoA)
ATP: adenosine triphosphate Ketone bodies come from from liver
Maple syrup urine disease results from defect in branched chain -keto acid dehydrogenase complex; special diet needed; 4 children in St. Louis.
GLUT1, GLUT3 in nervous tissue Brain accounts for 25% total body Glc utilization
Energy - 80% from Glc, up to 20% from ketone bodies, 5% from glycogen (main stores are astrocytes)
Astrocytes make lactate or pyruvate, which does not cross blood brain barrier
Unsaturated fatty acids can go through BBB (astrocytes do -oxidation, mitochondrial and peroxisomal)
BCAA
Ile, Leu, Val
Production of ATP

3. 5/20/2018
Review Questions
How does nervous tissue (neurons and glial cells) produce ATP (carbohydrates, fatty acids, ketone bodies, branched-chain amino acids)?
How do glial cells (astrocytes) assist neurons?