Lab 18BPhysioExEliciting a nerve impulseSlide 4Slide 5Slide 6Inhibiting a nerve impulseSlide 8Slide 9Nerve conduction velocitySlide 11Slide 12Turn inLab 18BNeurophysiology: Simulation of Nerve ImpulsesPhysioEx •CD-ROM came with lab manual•You will manipulate a model of a nerve – not a single neuron, but a bundle of axons – and see what happens•3 Exercises:–Eliciting a nerve impulse–Inhibiting a nerve impulse–Nerve conduction velocityEliciting a nerve impulseEliciting a nerve impulse•Set voltage at 1.0 by clicking + button•Click “Single Stimulus”•Increase voltage until you get a population action potential •Click “Record Data”•Increase by 0.5 and see what happens•Keep increasing until no further change•Record Data•Remember, you are not seeing a single AP, but a collection of action potentials in many axons within a nerve •Click ClearEliciting a nerve impulse•Click the glass rod and drag it over the nerve•Compare to your threshold AP (do it again to see them next to each other)•Record Data•Now drag the rod to the heater and click heat•When it turns red, drag it onto the nerve•Compare it to unheated trace•Record DataEliciting a nerve impulse•Click and drag the NaCl dropper over to the nerve and release drops – note what happens•Record Data•Now run a Single Stimulus at threshold and see how it differs from NaCl application•Clean and Clear•Repeat the drap and drop with HCl•Record Data, then compare with a Single StimulusInhibiting a nerve impulseInhibiting a nerve impulse•Chose I.a.n.i. from Experiment drop down•Test the effect of ether by clicking and dragging it onto the nerve, then set to threshold and Stimulate•Record Data•Now click on Time (min) to change time scale to 10 min•Set interval between stimuli to 2.0 min•Make sure it is set to threshold and click Stimulate – watch how long it takes to return to normal•Click Stop, return interval to 0.0 and Clean and ClearInhibiting a nerve impulse•Test the effects of cuare, an ACh blocker by clicking and dragging onto nerve•Stimulate at threshold and see what happens•Record Data•Clean and Clear•Test effects of lidocaine by dragging it and Stimulate at threshold•Record DataNerve conduction velocityNerve conduction velocity•Choose N.C.V from Experiment drop down•Compare 4 types of nerves in terms of conduction speed•Click Pulse, switch amplifier to on•Drop ether onto worm and then drag it onto stimulating apparatus•Start at 1.0V and Stimulate, increase (by 1V) until threshold reached•Click Measure, then click + until yellow line moves to place where AP starts•Record Data•Fill in Chart 1Nerve conduction velocity•Put earthworm back and repeat process for the remaining three nerves (no ethanol necessary):–Drag onto apparatus–Determine threshold–Measure and Record DataTurn in•Pages PEx-39 through PEx-48 with answers and data•Due next
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