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Neuro Block 1-RG > Brain Metabolism > Flashcards

Flashcards in Brain Metabolism Deck (16):
1

Is there glycogen in brain cells?

yes but very little

2

What type of cell modulates the blood flow through the neurovascular unit?

astrocytes
vasoconstriction/-dilation

3

Two functions of pentose phosphate pathway

five carbon sugars
NADPH

4

B1 deficiency affects which enzyme in which pathway

transketolase in pentose phosphate pathway

5

B1 deficiency leads to what clinical manifestation

Wernicke-Karakoff Syndrome

6

What is the tracer for glucose metabolism?

2-deoxyglucose

7

What is the astrocyte-neuron lactate shuttle?

glucose is taken from capillary into astrocyte where it is converted to lactate. the lactate then moves to the neuron where it is converted to pyruvate and burned in TCA.

8

What is the ATP from the Glc-->lactate rxn in the astrocyte used for?

Na+/K+ ATP (membrane potential)
glutamine-->glutamate conversion

9

How is glutamate recycled in a neuron?

glutamate moves from synaptic space into astrocyte where it is converted into glutamine using ATP. glutamine is then transferred into presynaptic neuron where is is converted back into glutamate.

10

What is the cerebral metabolic rate?

(arterial concentration - venous concentration)*(blood flow/weight)

11

Transketolase is an important part of which pathway in brain glucose metabolism?

pentose phosphate pathway

12

What cofactor does transketolase require?

vitamin B1

13

What is the pathological manifestation of thiamine deficiency?

Wernicke encephalopathy and Kasakoff psychosis

14

What is the tracer used in PET scans?

radiolabelled 2-deoxyglucose

15

What are the three regulated steps of glycolysis?

hexokinase
PFK
pyruvate kinase

16

What enzyme converts pyruvate to acetyl-CoA?

pyruvate dehydrogenase