The assembly of ionic currents in a thalamic neuron. II. The stability and state diagrams

The Royal Society - Tập 237 Số 1288 - Trang 289-312 - 1989
R. M. Rose1, J. L. Hindmarsh
1Department of Physiology, University of Wales College of Cardiff, U.K.

Tóm tắt

In the previous model of a thalamic neuron (R. M. Rose & J. L. Hindmarsh, Proc. R. Soc. Lond . B 237, 267-288 (1989)), which we referred to as the z -model, the burst response was terminated by the slow activation of a subthreshold outward current. In this paper we show that similar results can be obtained if the burst response is terminated by slow inactivation of the subthreshold inward current, I s a . We illustrate the use of this new model, which we refer to as the h a -model, by using it to explain the response of a thalamic neuron to a double ramp current. The main aim of the paper is to show how the stability and state diagrams introduced previously can be used to explain various types of firing pattern of thalamic and other neurons. We show that increasing the threshold for the fast action potentials leads to low threshold spikes of increased amplitude. Also, addition of a second subthreshold inward current adds a new stability region, which enables us to explain the origin of plateau potentials. In addition, various types of subthreshold oscillation are produced by relocating a previously stable equilibrium point in an unstable region. Finally, we predict a sequence of responses to current steps from different levels of background current that extends the burst, rest, tonic sequence of thalamic neurons. The stability and state diagrams therefore provide us with a useful way of explaining further properties of thalamic neurons and appear to have further applications to other mammalian neurons.

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Tài liệu tham khảo

Adams P. R., 1982, M-currents and other potassium currents in bullfrog sympathetic neurones. J.Physiol, Lond., 330, 537

10.1113/jphysiol.1988.sp016969

10.1016/S0006-3495(84)84037-0

10.1113/jphysiol.1987.sp016471

10.1113/jphysiol.1985.sp015594

10.1113/jphysiol.1986.sp016001

10.1113/jphysiol.1984.sp015153

10.1113/jphysiol.1984.sp015154

Llinas R. & Yarom Y. 1986 Oscillatory properties of guinea-pig inferior olivary neurones and

their pharmacological modulation: an invitro study. J. Physiol. Lond. 376 163-182.

10.1113/jphysiol.1983.sp014747

Meech R. W. 1978 Calcium-dependent potassium activation in nervous tissue. A . Rev. Biophys* Bioengng 7 1-18.

10.1523/JNEUROSCI.06-08-02134.1986

Nilius B., 1986, Possible functional significance of a novel type of cardiac Ca channel. Biomed. hiochim, Acta., 45, K37

10.1038/316440a0

Rinzel J. & Lee Y. S. 1986 On different mechanisms for membrane potential bursting. In Nonlinear oscillations in biology and chemistry (Lecture notes in biomathematics vol. 66) (ed. H. G. Othmer) pp. 19-33. New York: Springer.

10.1098/rspb.1985.0057

10.1098/rspb.1989.0049

10.1098/rspb.1989.0051

10.1152/jn.1985.54.6.1473

10.1016/0306-4522(88)90253-9

10.1152/jn.1988.59.1.212

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The Royal Society

Tập 237 Số 1288

289-312

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