Intrinsic membrane properties causing a bistable behaviour of α-motoneurones

J. Hounsgaard; H. Hultborn; B. Jespersen; O. Kiehn

doi:10.1007/BF00237290

Intrinsic membrane properties causing a bistable behaviour of α-motoneurones

J. Hounsgaard, H. Hultborn^*, B. Jespersen, O. Kiehn

^*Corresponding author af dette arbejde

177 Citationer (Scopus)

Abstract

In decerebrate cats a train of impulses in Ia afferents may lead to a sustained increase in excitability of α-motoneurones of homonymous and heteronymous muscles. It was previously suggested that this long-lasting excitability increase reflects a maintained synaptic input to the motoneurones from excitatory interneurones. With intracellular recording from motoneurones we here demonstrate that the sustained increase of α-motoneurone activity is due to an all-or-none plateau depolarization. This plateau can be induced by a short train of excitatory synaptic potentials or a brief, intracellularly injected depolarizing current pulse and is terminated by a short train of inhibitory synaptic potentials or a hyperpolarizing current pulse. It is concluded that maintained motor unit firing triggered by a brief train of impulses in Ia afferent reflects an intrinsic bistable behaviour of α-motoneurones.

Originalsprog	Engelsk
Tidsskrift	Experimental Brain Research
Vol/bind	55
Udgave nummer	2
Sider (fra-til)	391-394
Antal sider	4
ISSN	0014-4819
DOI	https://doi.org/10.1007/BF00237290
Status	Udgivet - 1 jun. 1984

Adgang til dokumentet

10.1007/BF00237290

Andre filer og links

Link to publication in Scopus

Citationsformater

@article{7166667d7bfe4231a5a6f26ccd8f6eca,

title = "Intrinsic membrane properties causing a bistable behaviour of α-motoneurones",

abstract = "In decerebrate cats a train of impulses in Ia afferents may lead to a sustained increase in excitability of α-motoneurones of homonymous and heteronymous muscles. It was previously suggested that this long-lasting excitability increase reflects a maintained synaptic input to the motoneurones from excitatory interneurones. With intracellular recording from motoneurones we here demonstrate that the sustained increase of α-motoneurone activity is due to an all-or-none plateau depolarization. This plateau can be induced by a short train of excitatory synaptic potentials or a brief, intracellularly injected depolarizing current pulse and is terminated by a short train of inhibitory synaptic potentials or a hyperpolarizing current pulse. It is concluded that maintained motor unit firing triggered by a brief train of impulses in Ia afferent reflects an intrinsic bistable behaviour of α-motoneurones.",

keywords = "Bistable state, Motoneurones, Serotonin, Spinal cord",

author = "J. Hounsgaard and H. Hultborn and B. Jespersen and O. Kiehn",

year = "1984",

month = jun,

day = "1",

doi = "10.1007/BF00237290",

language = "English",

volume = "55",

pages = "391--394",

journal = "Experimental Brain Research",

issn = "0014-4819",

publisher = "Springer",

number = "2",

}

TY - JOUR

T1 - Intrinsic membrane properties causing a bistable behaviour of α-motoneurones

AU - Hounsgaard, J.

AU - Hultborn, H.

AU - Jespersen, B.

AU - Kiehn, O.

PY - 1984/6/1

Y1 - 1984/6/1

N2 - In decerebrate cats a train of impulses in Ia afferents may lead to a sustained increase in excitability of α-motoneurones of homonymous and heteronymous muscles. It was previously suggested that this long-lasting excitability increase reflects a maintained synaptic input to the motoneurones from excitatory interneurones. With intracellular recording from motoneurones we here demonstrate that the sustained increase of α-motoneurone activity is due to an all-or-none plateau depolarization. This plateau can be induced by a short train of excitatory synaptic potentials or a brief, intracellularly injected depolarizing current pulse and is terminated by a short train of inhibitory synaptic potentials or a hyperpolarizing current pulse. It is concluded that maintained motor unit firing triggered by a brief train of impulses in Ia afferent reflects an intrinsic bistable behaviour of α-motoneurones.

AB - In decerebrate cats a train of impulses in Ia afferents may lead to a sustained increase in excitability of α-motoneurones of homonymous and heteronymous muscles. It was previously suggested that this long-lasting excitability increase reflects a maintained synaptic input to the motoneurones from excitatory interneurones. With intracellular recording from motoneurones we here demonstrate that the sustained increase of α-motoneurone activity is due to an all-or-none plateau depolarization. This plateau can be induced by a short train of excitatory synaptic potentials or a brief, intracellularly injected depolarizing current pulse and is terminated by a short train of inhibitory synaptic potentials or a hyperpolarizing current pulse. It is concluded that maintained motor unit firing triggered by a brief train of impulses in Ia afferent reflects an intrinsic bistable behaviour of α-motoneurones.

KW - Bistable state

KW - Motoneurones

KW - Serotonin

KW - Spinal cord

UR - http://www.scopus.com/inward/record.url?scp=0021258738&partnerID=8YFLogxK

U2 - 10.1007/BF00237290

DO - 10.1007/BF00237290

M3 - Journal article

C2 - 6086378

AN - SCOPUS:0021258738

SN - 0014-4819

VL - 55

SP - 391

EP - 394

JO - Experimental Brain Research

JF - Experimental Brain Research

IS - 2

ER -

Intrinsic membrane properties causing a bistable behaviour of α-motoneurones

Abstract

Adgang til dokumentet

Andre filer og links

Fingeraftryk

Citationsformater