Online citations, reference lists, and bibliographies.
Referencing for people who value simplicity, privacy, and speed.
Get Citationsy
← Back to Search

Threshold-spacing In Motoneurone Pools Of Rat And Cat: Possible Relevance For Manner Of Force Gradation

R. Bakels, D. Kernell
Published 2004 · Chemistry, Medicine

Save to my Library
Download PDF
Analyze on Scholarcy Visualize in Litmaps
Share
Reduce the time it takes to create your bibliography by a factor of 10 by using the world’s favourite reference manager
Time to take this seriously.
Get Citationsy
In the context of an analysis concerning factors of importance for the relative contributions of recruitment and rate gradation of muscle force, the distribution of electrical excitability was analyzed for medial gastrocnemius (MG) motoneurones of rat and cat. The experimental data came from previously collected intracellular measurements in animals anaesthetized with pentobarbitone. Electrical excitability was measured as the threshold (nanoamperes) for single spike generation (rheobase) in rat and for maintained repetitive firing (rhythmic threshold) in cat. Furthermore, the data included measurements of axonal conduction velocity and of contractile properties of the muscle units innervated by the studied motoneurones. The units were categorized into types S (slow-twitch, fatigue-resistant), FR (fast-twitch, fatigue-resistant) and FF (fast-twitch, fatiguable) on the basis of the combined criteria of twitch-speed and sensitivity to fatigue. We confirmed that, in spite of the presence of normal-looking symmetrical distributions of axonal conduction velocity, there was a positive skew in the distribution of electrical excitability (relatively high numbers of cells with low thresholds, few with high ones). Within each unit category (S, FR, FF), we ranked the motoneurones according to their relative electrical excitability and calculated the threshold difference between consecutive cells (“threshold spacing”). In accordance with the skewed distribution of electrical excitability, we found that the mean threshold spacing was ranked in the same way as the mean thresholds, i.e. S
This paper references
Neuromuscular fatigue and the differentiation of motoneurone and muscle unit properties
D Kernell (1993)
10.4449/AIB.V122I1.3214
Ionic mechanisms underlying excitation-to-frequency transduction: studies by voltage clamp methods.
W. Crill (1984)
10.1007/BF00239186
Relation between isometric force and stimulus rate in cat's hindlimb motor units of different twitch contraction time
Dr. D. Kernell (2004)
10.4449/AIB.V122I1.3212
The meaning of discharge rate: excitation-to-frequency transduction as studied in spinal motoneurones.
D. Kernell (1984)
10.4449/AIB.V130I1.622
Organized variability in the neuromuscular system: a survey of task-related adaptations.
D. Kernell (1992)
10.1152/JN.1993.69.4.1160
Physiological properties of motoneurons innervating different muscle unit types in rat gastrocnemius.
P. Gardiner (1993)
10.1016/0166-2236(85)90152-3
On factors determining orderly recruitment of motor units: a role for intrinsic membrane properties
B. Gustafsson (1985)
10.1016/0006-8993(81)90591-6
Input conductance, axonal conduction velocity and cell size among hindlimb motoneurones of the cat
D. Kernell (1981)
10.1113/jphysiol.1989.sp017652
Dendrites of cat's spinal motoneurones: relationship between stem diameter and predicted input conductance.
D. Kernell (1989)
10.1152/JN.1991.65.4.952
Computer simulation of the steady-state input-output function of the cat medial gastrocnemius motoneuron pool.
C. Heckman (1991)
10.1152/JN.1993.69.4.1005
Computer simulations of motoneuron firing rate modulation.
C. Heckman (1993)
10.1152/JN.1980.44.4.696
Tetrapartite classification of motor units of cat tibialis posterior.
J. McDonagh (1980)
10.1016/0304-3940(78)90090-3
Relations between cell body size, axon diameter and axon conduction velocity of cat sciatic α-motoneurons stained with horseradish peroxidase
S. Cullheim (1978)
10.1152/JN.1985.54.3.676
Classification of motor units in flexor carpi radialis muscle of the cat.
B. R. Botterman (1985)
Composition of peripheral nerves
I. A. Boyd (1968)
10.1126/science.152.3729.1637
Input Resistance, Electrical Excitability, and Size of Ventral Horn Cells in Cat Spinal Cord
D. Kernell (1966)
10.1002/CPHY.CP010210
Motor Units: Anatomy, Physiology, and Functional Organization
R. E. Burke (1981)
10.1016/0006-8993(79)90612-7
Rhythmic properties of motoneurones innervating muscle fibres of different speed in m. gastrocnemius medialis of the cat
D. Kernell (1979)
10.1016/0006-8993(81)90756-3
Threshold current for repetitive impulse firing in motoneurones innervating muscle fibres of different fatigue sensitivity in the cat
D. Kernell (1981)
10.1152/JN.1965.28.3.560
FUNCTIONAL SIGNIFICANCE OF CELL SIZE IN SPINAL MOTONEURONS.
E. Henneman (1965)
10.1152/JN.1965.28.1.85
PROPERTIES OF MOTOR UNITS IN A HETEROGENEOUS PALE MUSCLE (M. GASTROCNEMIUS) OF THE CAT.
A. M. McPhedran (1965)
10.1152/JN.1981.46.6.1326
Rheobase, input resistance, and motor-unit type in medial gastrocnemius motoneurons in the cat.
J. Fleshman (1981)
10.1016/0006-8993(90)90542-J
Synaptic effects on recruitment gain: a mechanism of importance for the input-output relations of motoneurone pools?
D. Kernell (1990)
10.1113/jphysiol.1973.sp010369
Physiological types and histochemical profiles in motor units of the cat gastrocnemius
R. Burke (1973)
10.1152/JN.1985.53.2.497
Distribution of oligosynaptic group I input to the cat medial gastrocnemius motoneuron pool.
R. Powers (1985)
10.1152/JN.1988.60.1.60
Electrotonic architecture of type-identified alpha-motoneurons in the cat spinal cord.
J. Fleshman (1988)
10.1007/BF00237177
Motoneurone properties and motor fatigue
Dr. D. Kernell (2004)
10.1063/1.1656831
Parametric Interaction of Focused Gaussian Light Beams
G. Boyd (1968)
10.1113/jphysiol.1993.sp019596
Matching between motoneurone and muscle unit properties in rat medial gastrocnemius.
R. Bakels (1993)
10.1113/jphysiol.1930.sp002657
The isometric responses of mammalian muscles
Sybil Cooper (1930)



This paper is referenced by
Semantic Scholar Logo Some data provided by SemanticScholar