Abstract
A nerve impulse propagating along a motor axon normally initiates a single action potential at points where the unmyelinated terminals branch off from their parent axon. In some vertebrate nerve-muscle preparations, this action potential continues to propagate actively along some portion of the nerve terminals (17), whereas in others it most probably depolarizes the terminals by only a passive spread of current (7). In either case, the resultant depolarization of the nerve terminals Is sufficient to trigger the synchronous release of the transmitter, acetylcholine (ACh), Into the junctional cleft.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Adams P.K., Brown D.A. and Constanti A. (1982). M-currents and other potassium currents in bullfrog sympathetic neurones. J. Physiol. 330, 537–572.
Alvarez-Leefmans F.J. and Miledl R. (1980). Voltage sensitive calcium entry in frog notoneurones. J. Physiol. 308, 241–257.
Barrett E.F. and Barrett J.N. (1976). Separation of two voltage-sensitive potassium currents, and demonstration of a tetrodotoxin-resistant calcium current in frog motoneurones. J. Physiol. 255, 737–774.
Barrett E.F., Barrett J.N. and Crill W.E. (1980). Voltage-sensitive outward currents in cat motoneurones. J. Physiol. 304, 251–276.
Benoit P.R. and Mambrini J. (1970). Modification of transmitter release by ions which prolong the presynaptic action potential. J. Physiol. (Lond.) 210, 681–695.
Bernardo L.S. and Prince D.A. (1982). Ionic mechanisms of cholinergic excitation in mammalian hippocampal pyramidal cells. Brain Res. 249, 333–344.
Brigant J.L. and Mallart A. (1982). Presynaptic currents in mouse motor endings. J. Physiol. (Lond.) 333, 619–636.
David G., Selzer M.E. and Yaari Y. (1984). Suppression by phenytoin of convulsant-induced afterdischarges at presynaptic nerve terminals. Brain Res. (in the press).
Frankenhaeuser B. and Hodgkin A.L. (1957). The action of calcium on the electrical properties of squid axons. J. Physiol. 137, 218–244.
Galvan M, Grafe P. and ten Bruggencate G. (1982). Convulsant actions of 4-aminopyridine on the guinea-pig olfactory cortex slice. Brain Res. 241, 75–86.
Galvan M. and Sedlmeir C. (1984). Outward currents in voltage-clamped rat sympathetic neurones. J. Physiol. 356, 115–133.
Gorman A. and Herman A.L.F. (1979). Internal effects of divalent cations on potassium permeability in molluscan neurones. J. Physiol. 296, 393–410.
Gundersen C.B., Katz B. and Miledi R. (1982). The antagonism between botullnum toxin and calcium in motor nerve terminals. Proc. R. Soc. Lond. B. 216, 369–376.
Gutnick M.J. and Prince D.A. (1972). Thalamocortical relay neurons: antldromlc invasion of spikes from a cortical eplleptogenic focus. Science 176, 424–426.
Hotson J.R. and Prince D.A. (1980). A calcium-activated hyperpolarization follows repetitive firing in hippocampal neurones. J. Neurophysiol. 43, 409–419.
Illes P. and Thesleff S. (1978). 4-Aminopyridine and evoked transmitter release from motor nerve endings. Br. J. Pharmacol. 64, 623–629.
Katz B. and Miledi R. (1965). Propagation of electric activity in motor nerve terminals. Proc. R. Soc. B. 161, 453–482.
Katz B. and Miledl R. (1967). A study of synaptlc transmission in the absence of nerve impulses. J. Physiol. 192, 407–436.
Katz B. and Miledi R. (1969). Tetrodotoxin-resistant electric activity in presynaptic terminals. J. Physiol. 203, 459–487.
Krnjevic K., PuiJ E. and Werman R. (1978). EGTA and motoneuron afterpotentials. J. Physiol. 275, 199–223.
Mallart A. (1984). Presynaptic currents in frog motor endings. Pflugers Arch. 400, 8–13.
Meech R.W. (1978). Calcium-dependent potassium activation in nervous tissue. Ann. Rev. Biophys. Bioeng. 7, 1–18.
Molgo J. and Thesleff S. (1982). Electrotonic properties of motor nerve terminals. Acta Physiol. Scand. 114, 271–275.
Noebels. J.L. and Prince D.A. (1977). Presynaptic origin of penicillin afterdischarges at mammalian nerve terminals. Brain Res. 138, 59–74.
Noebels. J.L. and Prince D.A. (1978). The development of focal seizures in cerebral cortex: role of axon terminal bursting. J. Neurophysiol. 41, 1267–1281.
Randic M. and Straughan D.W. (1964). Antidromic activity at the rat phrenic nerve-diaphragm preparation. J. Physiol. 173, 130–148.
Riker W.F. and Okamoto M. (1969). Pharmacology of motor nerve terminals. Ann. Rev. Pharmacol. 9, 173–208.
Schwartzkroin P.A. and Prince D.A. (1980). Effects of TEA on hippocampal neurones. Brain Res. 185, 169–181.
Schwarz E. and Passow H. (1983). Ca-activated K channels in erythrocytes and excitable cells. Ann. Rev. Physiol. 45, 359–374.
Scobey R.P. and Gabor A.J. (1975). Ectopic action-potential generation in epileptogenic cortex. J. Neurophysiol. 38, 383–394.
Segal M. and Barker J.L. (1984). Rat hippocampal neurons in culture: Potassium conductances. J. Neurophysiol. 51, 1409–1433.
Standaert F.G. (1963). Post-tetanic repetitive activity in cat soleus nerve. Its origin, cause and mechanism of generation. J. Gen. Physiol. 47, 53–70.
Werner G. (1960). Neuromuscular facilitation and antidromic discharges in motor nerves: their relation to activity in motor nerve terminals. J. Neurophysiol. 23, 171–187.
Yaari Y., Konnerth A. and Heinemann U. (1983). Spontaneous epileptiform activity of CA1 hippocampal neurones in low extracellular calcium solutions. Exp. Brain Res. 51, 153–156.
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1986 Martinus Nijhoff Publishing, Boston
About this chapter
Cite this chapter
David, G., Yaari, Y. (1986). Several Potassium Conductances Modulate the Excitability of Frog Motor Nerve Terminals. In: Rahamimoff, R., Katz, B. (eds) Calcium, Neuronal Function and Transmitter Release. Topics in the Neurosciences, vol 1. Springer, Boston, MA. https://doi.org/10.1007/978-1-4613-2307-5_39
Download citation
DOI: https://doi.org/10.1007/978-1-4613-2307-5_39
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4612-9420-7
Online ISBN: 978-1-4613-2307-5
eBook Packages: Springer Book Archive