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35 Cards in this Set
- Front
- Back
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Long term potentiation (LTP) is mediated by what post-synaptic channel? |
NMDA receptor. When the Mg which usually blocks the channel is expelled (due to post-synaptic membrane depolarization) the effects of glutamate are potentiated, playing a role in long term memory. |
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What ion is thought to be most significant in the effects of excitotoxicity? |
Calcium overload. (Many ions are not pumped in their energy-dependent fashion across their transmembrane gradient in the setting of excitotoxicity, but the Ca overload is thought to be the biggest factor) |
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What proteins accumulate in ALS? |
TDP43, SOD, FUS |
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What protein accumulates in Creutzfeldt-Jakob dz? |
Prion protein, Prp 27-30 |
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Proteins are degraded by what two mechanisms? |
Ubiquitin-proteosomal system or the lysosome |
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Lysosomes degrade protein by what process? |
Autophagy. Membrane forms around the targeted protein (called autophagosome), then fuses with the lysosome, which is full of hydrolases. |
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Axon transport: what are the three types of filamentous proteins in cells? |
Microfilaments, intermediate filaments, microtubules. |
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Neuron microfilaments are composed of what? |
Actin. Just below plasma membrane Aka plasmalemma. Involved in cell shape (growth cones, migration) |
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What motor proteins travel along the actin cytoskeleton? |
Myosins |
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Intermediate filaments are composed of what protein? |
Neurofilaments L, M, H-- a 10 nm twisted braid of all 3 |
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What motor protein functions on intermediate filaments? |
TRICK QUESTION! No motor proteins. Intermediate filaments provide structural and mechanical support to axons and dendrites. |
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Microtubules are composed of what protein? |
Alpha and beta tubulin |
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Front (Term) What types of axonal transport are there? |
Fast anterograde Slow anterograde Fast retrograde |
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Microtubules serve as train tracks for what? |
Vesicles and other organelles |
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Microtubules are polarized. The negative end is towards what part of the neuron? |
(-) end towards cell body |
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What motor proteins act on microtubules? |
Kinesins (-) end directed motors Dyneins (+) end directed motors |
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How does vincristine affect neurons? |
Binds tubulin dimers and inhibits assembly |
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Fast anterograde conduction happens where and by what mechanism? |
All new organelles, synaptic vesicles via saltatory conduction. Microtubules-based via kinesins. Requires oxidative metabolism. |
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Slow anterograde conduction happens via what proteins? |
Cytoskeleton elements (neurfilaments, tubulin, actin), but molecular basis is unknown |
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Fast retrograde conduction serves what purpose and utilizes what motor protein? |
Dynein. Informs cell body of events occurring at periphery |
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Vitamin B1 (thiamine) deficiency symptoms? |
Beri-beri. Wet beri-beri has CHF as predominant symptom where dry beri-beri has axonal sensori-motor neuropathy (burning paresthesia, distal sensory loss, distal weakness/wasting, shiny skin) |
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Vitamin B1 deficiency also can give what syndrome? |
Wernicke's encephalopathy |
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Vitamin B1 deficiency also can give what syndrome? |
Wernicke's encephalopathy |
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Wernicke's encephalopathy symptoms? |
Acute onset ocular abnormalities, ataxia, global confusional state |
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Vitamin B3 (niacin) deficiency symptoms? |
Diarrhea, dermatitis, dementia (also peripheral neuropathy) |
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Vitamin B6 (pyridoxine) deficiency symptoms? |
Neuropathy |
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Most common cause of B6 deficiency? |
Anti-TB Med, isoniazid |
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Vitamin B12 (cobalamin) deficiency symptoms? |
Combined System Degeneration |
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Symptoms of combined system Degeneration (B12 deficiency)? |
Myelopathy, neuropathy, acroparesthesia, sensory ataxia, memory loss, dementia, impotence |
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B12 dietary source and absorption? |
Meat. Taken up into the esophagus. In stomach, intrinsic factor and acid leads to the mobilization of B12, taken up in the terminal ileum into red blood cells, converted to adenosyl or methyl cobalamin and important for nervous system function. |
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Lab aberrations in B12 deficiency? |
Low B12 serum Increased methylmalonic acid Increased homocysteine |
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Abetalipoproteinemia (autosomal recessive) causes what problems? |
Interference with normal absorption of fat and fat-soluble vitamins (ADEK). Weight gain, diarrhea, acanthosis, steatorrhea, loss of balance, ataxia, retinopathy. TX with high doses of vitamin E |
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Caffeine acts on what receptor? |
Adenosine |
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MPTP is converted to its toxic metabolite, MPP+ by what enzyme? |
Monoamine oxidase |
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MPTP causes what symptoms by what mechanism? |
Parkinsonism by damage to nigrostriatal dopaminergic pathways |
