Brain Metabolism Flashcards
What is ATP used to maintain in the brain
Ionic gradient, molecule transport, and NT biosynthesis
What fuel can cross the BBB
Glucose (Glut-3)
What maintains glucose levels in brain during fasting state
Gluconeogenesis and Glycogenolysis
After a prolonged fast, what becomes the major brain fuel
Ketone bodies
Ketone bodies production reduces gluconeogenesis to spare body protein from AA degradation
Glucose sparing
Glucose uptake in the brain by GLUT-3 does not dependent on what
Insulin
Uptake of glucose and KB’s
Facilitated diffusion
Which transporter is used by KB, shared with pyruvate, lactate, and acetate
Monocarboxylate
What happens to the KB transporter during starvation
Unregulated by gene expression
Which fatty acids can cross the BBB
Dietary essential
Thiamine (Vit B-1) deficiency due to poor diet or alcoholism and responds to thiamine supplement
Wernicke-Korsakoff Syndrome
Symptoms of Wernicke-Korsakoff
Mental confusion
Ataxia
Ophthalmoplegia
Chronic state Wernicke-Korsakoff that causes retrograde and/or anterograde amnesia
Korsakoff psychosis
Thiamine (Vit B-1) deficiency due to mono cereal diet, polished white rice as main carb
Beri Beri
Small uncharged molecules and non-polar substances freely cross the BBB by
Passive diffusion
Hydrophobic drugs such as phenobarbital cross slower and bind to what protein in the blood
Albumin
Essential FA and vitamins need what to cross through BBB
Specific transporters
How do proteins such as insulin cross BBB
Receptor-mediated endocytosis
How do large neutral (essential) AA cross BBB
Facilitating transporter
In PKU patients, very high Phenylalanine levels overwhelm facilitative transporter and what occurs
Brain starved of other essential AA
Which AA and amines are blocked from crossing BBB b/c they can be synthesize in the brain
Glutamate and Aspartate
Dopamine and GABA
L-Dopa and DOPA carboxylase inhibitor are given together as treatment for
Parkinson’s
Where does the brain derive its specialized, complex and VLC lipids
Linoleic and Alpha-Linolenic Acid
VLC lipids are needed for synthesis of what
Myelin (70% lipid)
Myelin has a high content of what
Sphingomyelin and Cerebrosides
Two major proteins in myelin sheath
Proteolipid and Myelin Basic
Disease caused by progressive destruction of CNS myelin, forming sclerotic plaques
Multiple Sclerosis
Symptoms of Multiple Sclerosis
Weakness
Lack of coordination
Loss of vision
*Fatal
An autoimmune disease maybe triggered by viral infection
Multiple Sclerosis
Appearance of Multiple Sclerosis is dependent on what
Genetic and environmental influence (multifactorial etiology)
Disease caused by misfolded protein
Humans: CJD or Kuru
Sheep: Scrapie
Cattle: BSE
Cattle to Human: variant CJD
Prion Diseases
Misfolded Prion converts normal Prion to infectious form and forms what
Plaques on nuerons
Normal Prion has no what
B-sheets
Abnormal prion is composed of mostly what
B-sheets, resistant to protease digestion
Symptoms of Prion Disease
Neurodegeneration
Dementia
Paralysis
—> Death
Amyloid plaques of Alzheimer’s contain what
Amyloid-Beta-Peptide (42) which is neurotoxic
Alzheimer’s tangles contain which protein
Tau
Alzheimer’s results from the inappropriate accumulation of what proteolytic fragments
Beta-amyloid precursor protein
