Sound and vibration sensitivity of VIIIth nerve fibers in the frogs Leptodactylus albilabris and Rana pipiens pipiens

1993 ◽  
Vol 172 (6) ◽  
Author(s):  
J. Christensen-Dalsgaard ◽  
P.M. Narins
Keyword(s):  
Rana Pipiens ◽  
Nerve Fibers ◽  
Vibration Sensitivity ◽  
Viiith Nerve ◽  
Rana Pipiens Pipiens

scholarly journals CALCIUM INFLUX IN SKELETAL MUSCLE AT REST, DURING ACTIVITY, AND DURING POTASSIUM CONTRACTURE

1959 ◽  
Vol 42 (4) ◽  
pp. 803-815 ◽  
Author(s):  
C. Paul Bianchi ◽  
A. M. Shanes
Keyword(s):  
Skeletal Muscle ◽  
Rana Pipiens ◽  
Calcium Influx ◽  
Nerve Fibers ◽  
Sartorius Muscle ◽  
Potassium Contracture ◽  
Anion Substitution ◽  
Cent Increase ◽  
Fast Twitch ◽  
Passive Influx

Calcium influx in the sartorius muscle of the frog (Rana pipiens) has been estimated from the rate of entry of Ca45. In the unstimulated preparation it is about equal to what has been reported for squid giant axons, but that per impulse is at least 30 times greater than in nerve fibers. The enhanced twitch when NO-2 replaces Cl- in Ringer's is associated with at least a 60 per cent increase in influx during activity, whereas this anion substitution does not affect the passive influx significantly. Calcium entry during potassium contracture is even more markedly augmented than during electrical stimulation, but only at the beginning of the contracture; thus, when a brief Ca45 exposure precedes excess K+ application, C45 uptake is increased three- to fivefold over the controls not subjected to K+, whereas when C45 and K+ are added together, no measurable increase in Ca45 uptake occurs. These findings are in keeping with the brevity of potassium contracture in "fast (twitch)" fibers such as in sartorius muscle.

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