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44 Cards in this Set
- Front
- Back
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3 basic structures of a neuron
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•Dendrites (receptors)
•Soma (cell body; nucleus) •Axon (and terminals) |
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What determines neuronal function?
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Size, length, shape and localization
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What are the 5 ZONES and corresponding FUNCTIONS of the neuron?
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1. Somatodendric - reception
2. Somatic - integration, chemical encoding 3. Axon hilock - elec encoding 4. Axonal - Signal propogation 5. Presynaptic - signal output |
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Where does protein synthesis take place?
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Mostly in the soma. Sometimes in the dendrites.
No transport=immediate use |
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What are proteins broken down into? (2 thing)
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Protein> peptide> amino acid
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What are 2 TYPES of RIBOSOMES?
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Free polysomes - synthesize peripheral proteins (in cyto)
Rough Endoplasmic Ret (Nissl subs) - synthesize integral or secretory proteins (peptides) inserted into membrane |
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What are the steps in protein synthesis?
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DNA to mRNA - copy of info from the cell nucleus transcripted into mRNA.
mRNA read by 2 types ribosomes (1 peripheral,1 cytoplasm) |
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What does golgi apparatus do?
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modifies proteins into secretory vesicles ready for transport
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What are the 2 types of neuronal transport?
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Slow
Fast |
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What is carried via slow transport?
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•Used/discarded proteins and organelles
•Also growth factors and viruses which signal genome ****Parts for additional transport systems |
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What is carried via fast transport?
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•Secretory vesicles (Fastest)
•Elements for low-molecular weight neurotransmitter synthesis, metabolism, & utilization •Larger Neuropeptides ***All the things to build, transport and use monoamines |
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2 types of Fast Transport?
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Anterograde (soma to axon)
Retrograde (axon to soma) |
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What are the 4 primary structural and developmental processes of neurotransmission?
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•Neurodevelopment
•Migration •Synaptogenesis & Plasticity •Competitive Elimination of Synapses |
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Name 3 facts about neurodevelopment.
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•Most neurons formed/selected by 2nd trimester of pregnancy
•Up to 90% of neurons made by brain die before birth •Brain volume is ~95% of adult size by age 5 |
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What processes continue (to a lesser extent) throughout the lifespan?
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•Myelination, branching/arborization
•Competitive elimination of synapses |
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Where does neurogenesis continue throughout the lifespan?
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Hippocampus (memory)-Learning, exercise, etc. can promote growth factor production (restores function)
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Define Apoptosis
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slow cell death - helps refine brain. Reduce redundancy.
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Describe neuronal migration
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Occurs via tracing glial cells and adhesion molecules (chemical signals diff. from NTs)
After neurons reach destination, only axons can move |
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What diagnosis may be linked to improper neuronal migration?
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Those with strong developmental components - mental retardation
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What are 3 steps in synaptogenesis and plasticity?
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1. Neurotrophic factors cause growth cones on Axons - When syn 1st forming all terminal but. and syn are not in place - ingredients for presyn structure.
2. Axons repelled or attracted via rec molecules 3. Axon cone eventually collapses and docks at new syn |
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What do recognition molecules do?
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Repell or attract axons during synaptogenesis.
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What is a consequence of inadequate or msdirected synaptogenesis?
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Insufficient arborization (too few dendrites)
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List 3 types of synapses
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Axodendritic
Axosomatic Axoaxonic |
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What happens at hemisynapses?
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trial contact of adhesion molecules for potential growth of synapse (scaffolding) - this is a dynamic process - plasticity
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What is the purpose of competitive elimination?
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Pruning and refining connections
-From age 6, elimination of ⅓ to ½ of all synapses over 5-10 years |
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What is one method of competitive elimination?
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•Excitotoxicity via Glutamate - excessive excitation can =seizure, panic, pain, etc
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What makes up a COTRANSMITTER?
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combo of monoamine w a neuropeptide
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List the 6 CLASSIC NEUROTRANSMITTERS
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•5HT - Serotonin
•ACh - Acytlecholine •DA - Dopamine •GABA - GABA •Glu - glutamate •NE - norepinephrine |
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List 3 types of neurotransmission
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1. Classic transmission
2. Feedback circuits 3. Volume transmission |
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Describe the steps of classic transmission.
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1. Stimulation of presynaptic neuron causes electrical impulses to be sent to axon terminal
2. Impulses converted to chemical messengers n released to stimulate receptors of postsyn neuron |
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What is another name for Volume transmission?
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nonsynaptic diffusion - NTs released that "drift" to other receptors and/or neurons
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What are the 4 primary Signal Transduction Cascade Types?
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G Protein linked
Hormone linked Ion channel linked Neurotrophin-linked (receptor is tyrosime kinases - snyaptogenesis, learning/memory, disease expression) |
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What do all cascades target?
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phosphoproteins and ultimately gene expression
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Describe downregulation.
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Decrease in # of available receptors or slower production of new receptors.
Like reducing volume/noise Frequently caused by agonists (activate receptor changes)_ |
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Describe upregulation.
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Increase in # of available receptors
Often caused by Antagonists (prevent action of agonists or things that inhibit receptor changes) |
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What is tardive Dyskinesia an example of?
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Excessive upregulation of DA-ergic receptors. Usually caused by use of conventional antipsychotics (DA antagonists)
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Describe 2 of the cascades. What 2 use predominant neurotransmitters?
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G protein linked and ion-channel-linked use predominant NTs.
GPL - 1st messenger cAMP protein 2nd messenger protein kinase A 3rd mess. CREB protein 4th - gene expression ICL - 1st mess, Ca2+ 2nd, CaMK 3rd, CREB 4th |
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Describe 2 primary neuronal functions of the soma
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1. reception - via dendrites from other neurons, environment, chemicals, hormones, drugs, etc.,
2. Generates cascades of incoming chemical signals to eb decoded by genome - including protein synthesis. |
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Why is protein synthesis so important? What is a peptide?
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Protein synthesis is important because proteins are the building blocks of a new synapse. Synaptic connections cannot occur without the proteins that carry out the orders from genome to form a synapse.
Peptides are also known as integral or secretory proteins which are inserted into the membrane of a cell. Peptides are produced when mRNA is read by the rough endoplasmic reticulum. |
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Explain anterograde transport. What is transported in this fashion?
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Anterograde transport is a form of fast protein transport from the soma to the axon terminal. The book describes anterograde transport as the southbound traffic. Anterograde transport carries membrane bound secretory vesicles full of proteins.
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When is brain development the most dynamic? What developmental processes continue into adolescence and to a lesser extent throughout life?
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Brain development is most dynamic before birth, specifically from four weeks after conception until birth. Myelination of axon fibers and arborization of neurons continue through adolescence and to a lesser extent throughout the life span. Competitive elimination, or brain restructuring, also occurs throughout the lifetime but is most active during childhood and into adolescence.
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Explain differentiation. What area of our brain is especially equipped to restore itself via neurogenesis? Why is this fact important for clinical psychologists in particular to understand?
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Differentiation is the process whereby embryonic stem cells differentiate into immature neurons after conception. Then the most viable immature neurons are selected to further differentiate into different specific types of neurons in preparation for synaptogenesis.
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Why might apoptosis occur?
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Might occur to protect healthy neurons when DNA or another neuron is damaged
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Why are classic NTs called this?
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1st discovered
They've developed into the target systems for psychotropic drugs |
