Cell Biology of Neurons
Cell Biology of Neurons NSCI 3310
Popular in Cellular Neuroscience
Popular in Neuroscience
verified elite notetaker
This 4 page Class Notes was uploaded by Emma Notetaker on Tuesday September 29, 2015. The Class Notes belongs to NSCI 3310 at Tulane University taught by Jeffrey Tasker in Summer 2015. Since its upload, it has received 32 views. For similar materials see Cellular Neuroscience in Neuroscience at Tulane University.
Reviews for Cell Biology of Neurons
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 09/29/15
Cell Biology of Neurons 08/31/2015 WATCH THE VIDEOS!!!!! soma protein synthesis and packaging nucleus: transcription RER: protein synthesis (studded with ribosomes) Golgi apparatus (part of secretory pathway): modification and processing neurons differ from other cells by: excitability (ability to generate and potentiate action potential) morphology: signals need to travel long distances o protein trafficking (axonal transport): need a system for proteins to get to their desired endpoints proteins tagged, tags direct cell along cytoskeleton transcription mRNA formation from DNA template (in nucleus) encodes for one protein mRNA is a single strand o tRNA and nuclear pores traffic proteins from nucleus to cytoplasm translation protein synthesis: o amino acid assembly o translate info coded in mRNA o ribosomes are free (in cytoplasm) or in RER (membrane- associated) if exists only in cytoplasm, made on free ribosomes if exported, made in RER to be exported do NOT want to enter the cytoplasm – must keep vesicle around them until excretion some transmembrane proteins – part of protein will stay in the cytoplasm, part will end up elsewhere o video: ribosome assembles small and large subunit tRNA have amino acids in them codons on mRNA code for specific acids (translated by ribosomes) protein 1. cytosolic proteins o made by free ribosomes fibrillar – cytoskeletal elements enzymes – netabolic triggers 2. nuclear and mitochondrial o translocated into nucleus and mitochondria (binds to DNA in nucleus or mito), influence transcription of another gene) eg: transcription factors 3. membrane-associated proteins o 1. attached to membrane: integral – embedded in lipophilic (hydrophobic) membrane (amphipathic) peripheral – bound/associatedAZ to integral proteins o 2. ER proteins o 3. associated with vesicles, lysosomes (very acidic pH) secretory products, enzymes Golgi apparatus: pieces of Er buds off membrane to get here (if bein excreted – NOT cytosolic proteins) different regions with different environments posttranslational modifications – addition to protein that wasn’t part of original amino acid sequence (ex: glycosylation) o vesicle formation (@ end of golgi) – lysosomes, secretory vesicles with final, mature proteins axonal and dendritic projections large distances (even small neurons) – traveled via cytoskeletal framework (microtubules) o actin points on dendrites are spines o specific microtubules ONLY found in dendrites (not even in axons or spines) found with MAP2 staining protein transport mecnanisms dendritic spines – site of synapse cytoskeleton: 1. microtulues – made of protein tubulin o largest o hollow tubule o can be broken down from either end o POLAR (+ and – end) 2. neurofilaments – made of cytokeratins 3. microfilaments – made of actin o spirals o can grow on one end, break down on other end o dynamic process o intermediate filaments o twisted o keratin, lamin, axon transport: 1. fast anterograde: o synaptic vesicles/secretory granules o ATP-dependent (active transport) o + direction (away from soma, towards axon) o on microtubules at about – ‘’’’’’’’’’’’’’oo o motor protein = kinesin (ONLY goes in anterograde direction) 2. retrograde: o brings things back to soma (for degradation, recyclinc) o on microtubules at about ½ - 2/3 speed of fast anterograde o requires ATP (active transport) o motor protein = dynein o ex: Herpes virus 3. slow axoplasmic flow (anterograde direction) o .2-.5 mm/day o cytosolic proteins (enzymes for cytoskeletal) o DO NOT need ATP, no motor proteins cargo moves kinesin :carries cargo along microtubules in + direction (away from nucleus towards synapse) dynein: moves along microtubules in – direction towards nucleus can use labeled viruses to see which neurons are being used – reverse follow pathway modified rabies virus – cells connected to striatum ( voluntary movement) exocytosis: vesicle fusion to plasma membrane o secretion of proteins in vesicle lumen into extracellular space o chemical transmission – releasing molecules into synapse o insertion of vesicle membrane proteins into plasma membrane (becomes part of plasma membrane) new membrane proteins cellular energy: cell respiration – ATP production o ATP – energy source o phosphorylation of proteins ( o kinase activity – any enzyme that will add phosphate to other protein (acts as a switch to turn something on or off) changes from dormant to active o dephosphorylation (phosphatase activity) turns off - inactivated ▯ ▯