in [Baltimore .
Written in English
|Statement||by Horace Olin Patrick ...|
|LC Classifications||QP341 .P18|
|The Physical Object|
|Pagination||p. 481-495, 1 l.|
|Number of Pages||495|
|LC Control Number||42001376|
The frog sciatic nerve was the classical preparation for study of the action potential until experimental researchers developed intracellular recording methods for studying squid giant fibers. Action potentials can be elicited simultaneously by electrical stimulation in thousands of. myelination, excitability, threshold and conduction speed. Figure 1b Cross section of a frog’s sciatic nerve NOTE: The classification of different axons on the basis of diameter, myelination, electrical properties and conduction speed (etc.) is summarized in Table 1. B) The Compound Action Potential (CAP). The effect of bupivacaine on compound nerve action potential (CNAP) duration in isolated frog sciatic nerve. I: controls, II: after bupivacaine exposure, III: after 3-h wash, IV: after h wash. Download: Download full-size image; Fig. 5. The effect of bupivacaine on conduction velocity in isolated frog sciatic by: 5. ANODEBREAKEXCITATION the nerve, the threshold for anode break response wassometimes lower than the threshold for cathode makeresponse. Another condition which favours the anode break response is whenthe nerve is depolarized by an increased potassium-chloride concentration (Fig. 2, rec. 5and6) oranexternalcontinu- ouscurrentattheanodeofthe pulse. .
Excitability properties of isolated frog and rat sciatic nerve fibers were examined using intra-axonal and sucrose-gap recording techniques. Paired stimulation experiments on rat myelinated fibers indicate that a small proportion (11%;n = 84) of these axons demonstrate decreased threshold indicative of a supernormal contrast, 81% (n = 23) of frog . 1. Excised sciatic nerves of frogs,Rana esculenta, (including the 8th and 9th pair of spinal roots) were stimulated with long rectangular currents at the roots and at several sites throughout the nerve repetitive activity which resulted from the stimulation was recorded from isolated single myelinated nerve fibres belonging to peripheral nerve branches. Previous studies have shown that pulsed application of ultrasound waves to an excised frog sciatic nerve can modulate its excitability [7, 8]. However, the . 8. Find and dissect the frog sciatic nerve for placement in a nerve chamber. 9. Describe the dissection of the frog sciatic nerve. Explain the procedure and significance of a single and double pith of the frog. Introduction. The interior of a neuron at rest is negatively charged with respect to its exterior.
As a peripheral nerve model for studies of the SMF effects, we have investigated whether exposure of in vitro frog sciatic nerve fibers to moderate-intensity gradient SMF . Frog sciatic nerves show a continuing addition of new myelinated and nonmyelinated fibers with body growth. Along with increases in fiber number there are also marked changes in axon calibers and in the relative thickness of the myelin sheaths. Our data show that frog nerves, as opposed to mammalian nerves, are composed of fibers of different ages, stages of growth and stages of . Stimulation Recording in Frog Sciatic Nerve Methods: Dissection of the Gastrocnemius Muscle and the Sciatic Nerve In this experiment the frog sciatic nerve was used; the frogs were carefully handled and deeply anesthetized in order to be permanently unconscious. Pithing was used to destroy the brain pain center making the frog insensitive to pain. (not in frog sciatic nerve) C - unmyelinated fibers, pain receptor fibers Largest Fibers are affected first by pressure ŁAt end of Experiment try crushing the nerve bundle to see if you can eliminate α responses Vertebrate Neuron Fiber Types Fiber class Fiber diameter (mm) Velocity (m/s) A a Myelinated skeletal, muscle sensory 42 A b.