cogs 1 midterm 1 study guide

cogs 1 midterm 1 study guide - Week 1 - Lecture 2 Basics of...

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Week 1 - Lecture 2 Basics of Neurophysiology by Mary Boyle Questions 1. How do neurons fire an action potential? 2. What are the major forces at play - both in holding the neuron in equilibrium, and in the firing of an action potential? 3. How does the membrane potential change with the influx of an EPSP, and how (and when) do those changes facilitate an action potential? becomes more positive. reaches the threshold of excitation. Voltage gated ion channels. Sodium Potassium Pump. sodium goes in. 4. Does an EPSP ALWAYS lead to the firing of an action potential? What is an IPSP? An EPSP influx of Na+. IPSP is an efflux of K+ and influx of Cl- that leads to hyperpolarization. 5. What types of receptors and channels did Dr. Boyle discuss? How do they work, and what are their functions? voltage gated calcium channel causes synaptic vessels to release neurotransmitters, ion chaanel (NA-K pump) creates action potential. ionotropic recepter binds neurotransmitter to release ion channel (directly) Metabotropic Receptor (indirect) neurotransmitter binds to receptor → receptor activates g-protein → alpha subunit of g-protein binds to ion channel to open it OR alpha subunit binds to enzyme → enzyme produces 2nd messenger → ion channel opens presynaptic receptor = autoreceptors Keyterms electrode - a conductive medium that can be used to apply electrical stimulation or to record electrical potentials membrane potential - The electrical charge across a cell membrane; the difference in electrical potential inside and outside the cell. oscilloscope - A laboratory instrument that is capable of displaying a graph of voltage as a function of time on the face of a cathode ray tub resting potential - The membrane potential of a neuron when it is not being altered by excitatory or inhibitory postsynaptic potential; approximately -70 mV in the giant squid axon depolarization - Reduction (toward zero) of the membrane potential of a cell from its normal resting potential hyperpolarization - An increase in the membrane potential of a cell, relative to the normal resting potential Action potential - The brief electrical impulses that provide the basis for conduction of information along an axon. threshold of excitation - The value of the membrane potential that must be reached to produce an action potential. diffusion - Movement of molecules from regions of high concentration to regions of low concentration selective permeability electrostatic pressure - The attractive force between atomic particles charged with opposite signs or repulsive force between atomic particles charged with the same charge voltage gated ion channel - An ion channel is a specialized protein molecule that permits specific ions to enter or leave cells.A voltage gated ion channel is one that opens or closes according to the value of the membrane potential Na-K pump - activated by a neurotransmitter creates a difference in membrane potential. 2 potassium out, 3 sodium in refractory period -at about the time an action potential reaches its peak, sodium channel becomes blocked and
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This note was uploaded on 02/02/2012 for the course COGS 1 taught by Professor Lewis during the Winter '08 term at UCSD.

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cogs 1 midterm 1 study guide - Week 1 - Lecture 2 Basics of...

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