Physiology of the motor neuron and the motor unit

Handbook of Clinical Neurophysiology

Volumn 4, Issue C, 2004, Pages 119-147

  Heckman, C J ^a   Enoka, Roger M ^b  

^a NORTHWESTERN UNIVERSITY   (United States)

^b UNIVERSITY OF COLORADO   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 28844469570     PISSN: 15674231     EISSN: None     Source Type: Book Series    
DOI: 10.1016/S1567-4231(04)04006-7     Document Type: Article

References (223)

1. Adrian E., and Bronk D. The discharge of impulses in motor nerve fibres. Part II. The frequency of discharges in reflex and voluntary contractions. J. Physiol 67 (1929) 119-151
2. Adrian R.H., Costantin L.L., and Peachey L.D. Radial spread of contraction in frog muscle fibres. J. Physiol 204 (1969) 231-257
3. Alaburda A., Perrier J.F., and Hounsgaard J. Mechanisms causing plateau potentials in spinal motoneurones. Adv. Exp. Med. Biol 508 (2002) 219-226
4. Allum J.H., Dietz V., and Freund H.J. Neuronal mechanisms underlying physiological tremor. J. Neurophysiol 41 (1978) 557-571
5. Alvarez F.J., Pearson J.C., Harrington D., Dewey D., Torbeck L., and Fyffe R.E. Distribution of 5-hydroxytryptamine-immunoreactive boutons on alpha-motoneurons in the lumbar spinal cord of adult cats. J. Comp. Neurol 393 (1998) 69-83
6. Alvarez F.J., Villalba R.M., Carr P.A., Grandes P., and Somohano P.M. Differential distribution of metabotropic glutamate receptors 1a, 1b, and 5 in the rat spinal cord. J. Comp. Neurol 422 (2000) 464-487
7. Ashley C.C., and Ridgway E.B. Simultaneous recording of membrane potential, calcium transient and tension in single muscle fibers. Nature 219 (1968) 1168-1169
8. Ashley C.C., and Ridgway E.B. On the relationships between membrane potential, calcium transient and tension in single barnacle muscle fibres. J. Physiol 209 (1970) 105-130
9. Aston-Jones G., Rajkowski J., and Cohen J. Locus coeruleus and regulation of behavioral flexibility and attention. Prog. Brain Res 126 (2000) 165-182
10. Bakels R., and Kernell D. Matching between motoneurone and muscle unit properties in rat medial gastrocnemius. J. Physiol 463 (1993) 307-324
11. Bakels R., and Kernell D. Average but not continuous speed match between motoneurons and muscle units of rat tibialis anterior. J. Neurophysiol 70 (1993) 1300-1306
12. Bárány M. ATPase activity of myosin correlated with speed of muscle shortening. J. Gen. Physiol 50 (1967) 197-218
13. Baratta R.V., Solomonow M., Best R., and D'Ambrosia R. Isotonic length/force models of nine different skeletal muscles. Med. Biol. Engng. Comput 31 (1993) 449-458
14. Barrett E.F., Barrett J.N., and Crill W.E. Voltage-sensitive outward currents in cat motoneurones. J. Physiol. (Lond.) 304 (1980) 251-276
15. Bennett D.J., Hultborn H., Fedirchuk B., and Gorassini M. Synaptic activation of plateaus in hindlimb motoneurons of decerebrate cats. J. Neurophysiol 80 (1998) 2023-2037
16. Bessou P., Emonet-Dénand F., and Laporte Y. Relation entre la vitesse de conduction des fibres nerveuses mortices et le tempe de contraction de leurs unites motrices. CR. Acad. Sci. Ser. D 256 (1963) 5625-5627
17. Bigland B., and Lippold O.C.J. Motor unit activity in the voluntary contraction of human muscle. J. Physiol 125 (1954) 322-335
18. Binder M.D., Heckman C.J., and Powers R.K. The physiological control of motoneuron activity. In: Rowell L.B., and Shepherd J.T. (Eds). Handbook of Physiology. Exercise: Regulation and Integration of Multiple Systems (1996), Oxford University Press, New York 1-53
19. Binder M.D., Heckman C.J., and Powers R.K. Relative strengths and distributions of different sources of synaptic input to the motoneurone pool: implications for motor unit recruitment. Adv. Exp. Med. Biol 508 (2002) 207-212
20. Björklund A., and Skagerberg G. Descending monoaminergic projections to the spinal cord. In: Sjolund B., and Bjorklund A. (Eds). Brain Stem Control of Spinal Mechanisms (1982), Elsevier Biomedical Press, Amsterdam 55-58
21. Black J.A., Kocsis J.D., and Waxman S.G. Ion channel organization of the myelinated fiber. Trends Neurosci 13 (1990) 48-54
22. Bloch R.J., and Gonzalez-Serratos H. Lateral force transmission across costameres in skeletal muscle. Exerc. Sport Sci. Rev 31 (2003) 73-78
23. Bodine S.C., Roy R.R., Eldred E., and Edgerton V.R. Maximal force as a function of anatomical features of motor units in the cat tibialis anterior. J. Neurophysiol 57 (1987) 1730-1745
24. Booth F., and Baldwin K. Muscle plasticity: energy demand and supply processes. In: Rowell L.B., and Shepherd J.T. (Eds). Handbook of Physiology, Section 12. Exercise: Regulation and Integration in Multiple Systems (1996), Oxford University Press, New York 1075-1123
25. Bottinelli R., Canepari M., Pellegrino M.A., and Reggiani C. Force-velocity properties of human skeletal muscle fibres: myosin heavy chain isoform and temperature dependence. J. Physiol 495 (1996) 573-586
26. Bottinelli R., Pellegrino M.A., Canepari M., Rossi R., and Reggiani C. Specific contributions of various muscle fibre types to human muscle performance: an in vitro study. J. Electromyogr. Kinesiol 9 (1999) 87-95
27. Bowker R.M., Westlund K.N., Sullivan M.C., and Coulter J.D. Organization of descending serotonergic projections to the spinal cord. In: Kuypers H.G.J.M., and Martin G.F. (Eds). Descending Pathways to the Spinal Cord. Progress in Brain Research (1982), Elsevier, Amsterdam 239-265
28. Brown I.E., and Loeb G.E. Measured and modeled properties of mammalian skeletal muscle. I. The effects of post-activation potentiation on the time course and velocity dependencies of force production. J. Muscle Res. Cell Motil 20 (1999) 443-456
29. Buchthal F. The general concept of the motor unit. Neuromuscular disorders. Res. Publ. Assoc. Res. Nerv. Ment. Dis 38 (1961) 3-30
30. Burke R.E. Motor unit types of cat triceps surae muscle. J. Physiol 193 (1967) 141-160
31. Burke R.E. Motor units: anatomy, physiology, and functional organization. In: Brooks V.B. (Ed). Handbook of Physiology, The Nervous System, Motor Control (1981), American Physiological Society, Bethesda, MD 345-422
32. Burke R.E., and Tsairis P. The correlation of physiological properties with histochemical characteristics in single muscle units. Ann. New York Acad. Sci 228 (1974) 145-159
33. Burke R.E., and Glenn L.L. Horseradish peroxidase study of the spatial and electrotonic distribution of group Ia synapses on type-identified ankle extensor motoneurons in the cat. J. Comp. Neurol 372 (1996) 465-485
34. Burke R.E., Jankowska E., and Ten Bruggencate G. A comparison of peripheral and rubrospinal synaptic input to slow and fast twitch motor units of triceps surae. J. Physiol 207 (1970) 709-732
35. Burke R.E., Fedina L., and Lundberg A. Spatial synaptic distribution of recurrent and group Ia inhibitory systems in cat spinal motoneurones. J. Physiol 214 (1971) 305-326
36. Burke R.E., Levine D.N., Tsairis P., and Zajac F.E. Physiological types and histochemical profiles in motor units of the cat gastrocnemius. J. Physiol 234 (1973) 723-748
37. Burke R.E., Rudomin P., and Zajac F.E. The effect of activation history on tension production by individual muscle units. Brain Res 109 (1976) 515-529
38. Burke R.E., Strick P.L., Kanda K., Kim C.C., and Walmsley B. Anatomy of medial gastrocnemius and soleus motor nuclei in cat spinal cord. J. Neurophysiol 40 (1977) 667-680
39. Burke R.E., Dum R.P., Fleshman J.W., Glenn L.L., Lev T.A., O'Donovan M.J., and Pinter M.J. A HRP study of the relation between cell size and motor unit type in cat ankle extensor motoneurons. J. Comp. Neurol 209 (1982) 17-28
40. Carlin K.P., Jones K.E., Jiang Z., Jordan L.M., and Brownstone R.M. Dendritic L-type calcium currents in mouse spinal motoneurons: implications for bistability. Eur. J. Neurosci 12 (2000) 1635-1646
41. Carlsöö S. Motor units and action potentials in masticatory muscles. An electromyographic study of the form and duration of the action potentials and an anatomic study of the size of the motor units. Acta. Morphol. Neerl. Scand 2 (1958) 13-19
42. Christakos C.N. A study of the muscle force waveform using a population stochastic model of skeletal muscle. Biol. Cybern 44 (1982) 91-106
43. Christensen E. Topography of terminal motor innervation in striated muscles from stillborn infants. Am. J. Phys. Med 38 (1959) 65-78
44. Clarkson P.M., and Hubal M.J. Exercise-induced muscle damage in humans. Am. J. Phys. Med. Rehabil 81 (2002) S52-S69
45. Clements J.D., and Redman S.J. Cable properties of cat spinal motoneurones measured by combining voltage clamp, current clamp and intracellular staining. J. Physiol 409 (1989) 63-87
46. Clements J.D., Nelson P.G., and Redman S.J. Intracellular tetraethylammonium ions enhance group Ia excitatory post-synaptic potentials evoked in cat motoneurones. J. Physiol 377 (1986) 267-282
47. Conradi S., Cullheim S., Gollvik L., and Kellerth J.O. Electron microscopic observations on the synaptic contacts of group Ia muscle spindle afferents in the cat lumbosacral spinal cord. Brain Res 265 (1983) 31-39
48. Coombs J.S., Eccles J.C., and Fatt P. The electrical properties of the motoneurone membrane. J. Physiol 130 (1955) 291-325
49. Coombs J.S., Eccles J.C., and Fatt P. The specific ionic conductances and the ionic movements across the motoneuronal membrane that produce the inhibitory post-synaptic potential. J. Physiol 130 (1955) 326-373
50. Coombs J.S., Eccles J.C., and Fatt P. Excitatory synaptic action in motoneurones. J. Physiol 130 (1955) 326-373
51. Cooper S., and Eccles J.C. The isometric responses of mammalian muscles. J. Physiol 69 (1930) 377-385
52. Cope T., and Pinter M. The size principle: still working after all these years. News Physiol. Sci 10 (1995) 280-286
53. Cordo P.J., and Rymer W.Z. Contributions of motor-unit recruitment and rate modulation to compensation for muscle yielding. J. Neurophysiol 47 (1982) 797-809
54. Crill W.E. Persistent sodium current in mammalian central neurons. Annu. Rev. Physiol 58 (1996) 349-362
55. Cullheim S., Fleshman J.W., Glenn L.L., and Burke R.E. Membrane area and dendritic structure in type-identified triceps surae alpha motoneurons. J. Comp. Neurol 255 (1987) 68-81
56. Damiani E., and Margreth A. Characterization study of the ryanodine receptor and of calsequestrin isoforms of mammalian skeletal muscles in relation to fibre types. J. Muscle Res. Cell Motil 15 (1994) 86-101
57. De Luca C.J., LeFever R.S., McCue M.P., and Xenakis A.P. Behavior of human motor units in different muscles during linearly varying contractions. J. Physiol 329 (1982) 113-128
58. De Luca C.J., Foley P.J., and Erim Z. Motor unit control properties in constant-force isometric contractions. J. Neurophysiol 76 (1996) 1503-1516
59. Denny-Brown D., and Pennybacker J.B. Fibrillation and fasciculation in voluntary muscle. Brain 61 (1938) 311-334
60. Desmedt J.E., and Godaux E. Fast motor units are not preferentially activated in rapid voluntary contractions in man. Nature 267 (1977) 717-719
61. Devanne H., Lavoie B.A., and Capaday C. Input-output properties and gain changes in the human corticospinal pathway. Exp. Brain Res 114 (1997) 329-338
62. Dulhunty A.F., Haarmann C.S., Green D., Laver D.R., Board P.G., and Casarotto M.G. Interactions between dihydropyridine receptors and ryanodine receptors in striated muscle. Prog. Biophys. Mol. Biol 79 (2002) 45-75
63. Dum R.P., and Kennedy T.T. Physiological and histochemical characteristics of motor unit in cat tibialis anterior and extensor digitorum longus muscles. J. Neurophysiol 43 (1980) 1615-1630
64. Dum R., and Strick P. The corticospinal system: a structural framework for the central control of movement. In: Rowell L.B., and Shepherd J.T. (Eds). Handbook of Physiology, Section 12. Exercise: Regulation and Integration in Multiple Systems (1996), Oxford University Press, New York 217-254
65. Ebashi S., Endo M., and Otsuki I. Control of muscle contraction. Q. Rev. Biophys 2 (1969) 351-384
66. Edman K.A.P. Double-hyperbolic force-velocity relation in frog muscle fibres. J. Physiol 404 (1988) 301-321
67. Edman K.A.P., Reggiani C., Schiaffino S., and Te Kronnie G. Maximum velocity of shortening related to myosin isoform composition in frog skeletal muscle fibres. J. Physiol 395 (1988) 679-694
68. Edstrom L., and Kugelberg E. Histochemical composition, distribution of fibres and fatiguability of single motor units. Anterior tibial muscle of the rat. J. Neurol. Neurosurg. Psychiatry 31 (1968) 424-433
69. Edwards R.H., Dawson M.J., Wilkie D.R., Gordon R.E., and Shaw D. Clinical use of nuclear magnetic resonance in the investigation of myopathy. Lancet 1 (1982) 725-731
70. Endo K., Araki T., and Kawai Y. Contra- and ipsilateral cortical and rubral effects on fast and slow spinal motoneurons of the cat. Brain Res 88 (1975) 91-98
71. Ennion S., Sant'ana Pereira J., Sargeant A.J., Young A., and Goldspink G. Characterization of human skeletal muscle fibres according to the myosin heavy chains they express. J. Muscle Res. Cell Motil 16 (1995) 35-43
72. Enoka R.M. Human Kinetics. Neuromechanics of Human Movement 3rd ed (2002), Champaign-Urbaba, IL
73. Enoka R.M., and Fuglevand A.J. Motor unit physiology: some unresolved issues. Muscle Nerve 24 (2001) 4-17
74. Enoka R.M., Robinson G.A., and Kossev A.R. Task and fatigue effects on low-threshold motor units in human hand muscle. J. Neurophysiol 62 (1989) 1344-1359
75. Enoka R.M., Christou E.A., Hunter S.K., Kornatz K.W., Semmler J.G., Taylor A.M., and Tracy B.L. Mechanisms that contribute to differences in motor performance between young and old adults. J. Electromyogr. Kinesiol 13 (2003) 1-12
76. Faaborg-Andersen K. Electromyographic investigation of intrinsic laryngeal muscles in humans. Acta. Physiol. Scand 41 Suppl 140 (1957) 1-149
77. Fatt P., and Katz B. An analysis of the end-plate potential recorded with an intracellular electrode. J. Physiol 115 (1951) 320-370
78. Feinstein B., Lindegård B., Nyman E., and Wohlfart G. Morphologic studies of motor units in normal human muscles. Acta. Anat 23 (1955) 127-142
79. Fleshman J.W., Munson J.B., Sypert G.W., and Friedman W.A. Rheobase, input resistance, and motor-unit type in medial gastrocnemius motoneurons in the cat. J. Neurophysiol 46 (1981) 1326-1338
80. Forsythe I.D., and Redman S.J. The dependence of motoneurone membrane potential on extracellular ion concentrations studied in isolated rat spinal cord. J. Physiol 404 (1988) 83-99
81. Fuglevand A.J., Winter D.A., and Patla A.E. Models of recruitment and rate coding organization in motor-unit pools. J. Neurophysiol 70 (1993) 2470-2488
82. Fuglevand A.J., Macefield V.G., and Bigland-Ritchie B. Force-frequency and fatigue properties of motor units in muscles that control digits of the human hand. J. Neurophysiol 81 (1999) 1718-1729
83. Fukushima K., Peterson B.W., and Wilson V.J. Vestibulospinal, reticulospinal and interstitiospinal pathways in the cat. Prog. Brain Res 50 (1979) 121-136
84. Fyffe R.E.W. Spinal motoneurons: synaptic inputs and receptor organization. In: Cope T.C. (Ed). Motor biology of the spinal cord (2001), CRC press, London 21-46
85. Gandevia S.C. Spinal and supraspinal factors in human muscle fatigue. Physiol. Rev 81 (2001) 1725-1789
86. Gillard D.M., Yakovenko S., Cameron T., and Prochazka A. Isometric muscle length-tension curves do not predict angle-torque curves of human wrist in continuous active movements. J. Biomech 33 (2000) 1341-1348
87. Gollnick P.D., Armstrong R.B., Saubert C.W.T., Sembrowich W.L., Shepherd R.E., and Saltin B. Glycogen depletion patterns in human skeletal muscle fibers during prolonged work. Pflugers Arch 344 (1973) 1-12
88. Gordon A., Huxley A., and Julian F. The variation in isometric tension with sarcomere length in vertebrate muscle fibres. J. Physiol 184 (1966) 170-192
89. Gordon D.A., Enoka R.M., and Stuart D.G. Motor-unit force potentiation in adult cats during a standard fatigue test. J. Physiol 421 (1990) 569-582
90. Gordon T., Tyreman N., Rafuse V.F., and Munson J.B. Limited plasticity of adult motor units conserves recruitment order and rate coding. Prog. Brain Res 123 (1999) 191-202
91. Gordon A.M., Regnier M., and Homsher E. Skeletal and cardiac muscle contractile activation: tropomyosin "rocks and rolls". News Physiol. Sci 16 (2001) 49-55
92. Gray S.D. Histochemical analysis of capillary and fiber-type distributions in skeletal muscles of spontaneously hypertensive rats. Microvasc. Res 36 (1988) 228-238
93. Grimby L., and Hannerz J. Firing rate and recruitment order of toe extensor motor units in different modes of voluntary contraction. J. Physiol 264 (1977) 865-879
94. Grosse P., and Brown P. Acoustic startle evokes bilateral synchronous oscillatory EMG activity in the healthy human. J. Neurophysiol 90 (2003) 1654-1661
95. Gustafsson B., and Pinter M.J. Relations among passive electrical properties of lumbar alpha-motoneurones of the cat. J. Physiol 356 (1984) 401-431
96. Gustafsson B., and Pinter M.J. An investigation of threshold properties among cat spinal alpha-motoneurones. J. Physiol 357 (1984) 453-483
97. Gydikov A., and Kosarov D. Some features of different motor units in the biceps brachii muscle. Pflugers Arch 347 (1974) 75-88
98. Hamm T.M., Nemeth P.M., Solanki L., Gordon D.A., Reinking R.M., and Stuart D.G. Association between biochemical and physiological properties in single motor units. Muscle Nerve 11 (1988) 245-254
99. Hannerz J. Discharge properties of motor units in relation to recruitment order in voluntary contraction. Acta Physiol. Scand 91 (1974) 374-385
100. Harridge S.D., Bottinelli R., Canepari M., Pellegrino M.A., Reggiani C., Esbjornsson M., and Saltin B. Whole-muscle and single-fibre contractile properties and myosin heavy chain isoforms in humans. Pflugers Arch 432 (1996) 913-920
101. Heckman C.J., and Binder M.D. Analysis of effective synaptic currents generated by homonymous Ia afferent fibers in motoneurons of the cat. J. Neurophysiol 60 (1988) 1946-1966
102. Heckman C.J., and Binder M.D. Computer simulation of the steady-state input-output function of the cat medial gastrocnemius motoneuron pool. J. Neurophysiol 65 (1991) 952-967
103. Heckman C.J., and Binder M.D. Computer simulations of the effects of different synaptic input systems on motor unit recruitment. J. Neurophysiol 70 (1993) 1827-1840
104. Heckman C.J., Weytjens J.F.L., and Loeb G.F. Effect of velocity and mechanical history on the forces of motor units in the cat medial gastrocnemius muscle. J. Neurophysiol 68 (1992) 1503-1515
105. Heckman C.J., Lee R.H., and Brownstone R.M. Hyperexcitability of motoneuron dendrites and their neuromodulatory control during motor behavior. Trends Neurosci (2004) in press
106. Hellstrom J., Oliveira A.L., Meister B., and Cullheim S. Large cholinergic nerve terminals on subsets of motoneurons and their relation to muscarinic receptor type 2. J. Comp. Neurol 460 (2003) 476-486
107. Henneman E. Relation between size of neurons and their susceptibility to discharge. Science 126 (1957) 1345-1347
108. Henneman E. Comments on the logical basis of muscle control. In: Binder M.D., and Mendell L.M. (Eds). The Segmental Motor System (1990), Oxford University Press, New York vi, x
109. Henneman E., and Olson C.B. Relations between structure and function in the design of skeletal muscle. J. Neurophysiol 28 (1965) 581-598
110. Henneman E., and Mendell L.M. Functional organization of motoneuron pool and its inputs. In: Brooks V.B. (Ed). Handbook of Physiology, The Nervous System, Motor Control (1981), American Physiological Society, Bethesda, MD 423-507
111. Hill A.V. The heat of shortening and the dynamic constraints of muscle. Proc. R. Soc. Lond B126 (1938) 136-195
112. Hille B. Ionic Channels of Excitable Membranes. 3rd ed. (2001), Sinauer Assoc. Inc, Sunderland, MA
113. Hochman S., Garraway S.M., Machacek D.W., and Shay B.L. 5-HT receptors and the neuromodulatory control of spinal cord function. In: Cope T.C. (Ed). Motor Neurobiology of the Spinal Cord (2001), CRC Press, London 47-87
114. Hodgkin A., and Horowicz P. The influence of potassium and chloride ions on the membrane potential of single muscle fibers. J. Physiol 148 (1959) 127-160
115. Holstege G. The emotional motor system. Eur. J. Morphol 30 (1992) 67-79
116. Hongo T., Jankowska E., and Lundberg A. The rubrospinal tract. I. Effects on alpha-motoneurones innervating hindlimb muscles in cats. Exp. Brain Res 7 (1969) 344-364
117. Horak F., and Macpherson J. Postural orientation and equilibrium. In: Rowell L.R., and Shepherd J.S. (Eds). Handbook of Physiology, Section 12. Exercise: Regulation and Integration in Multiple Systems (1996), Oxford University Press, New York 255-292
118. Hornby T.G., McDonagh J.C., Reinking R.M., and Stuart D.G. Motoneurons: A preferred firing range across vertebrate species?. Muscle Nerve 25 (2002) 632-648
119. Hounsgaard J., and Kiehn O. Serotonin-induced bistability of turtle motoneurones caused by a nifedipine-sensitive calcium plateau potential. J. Physiol 414 (1989) 265-282
120. Hounsgaard J., Hultborn H., Jespersen B., and Kiehn O. Bistability of alpha-motoneurones in the decerebrate cat and in the acute spinal cat after intravenous 5-hydroxytryptophan. J. Physiol 405 (1988) 345-367
121. Huang A., Noga B.R., Carr P.A., Fedirchuk B., and Jordan L.M. Spinal cholinergic neurons activated during locomotion: localization and electrophysiological characterization. J. Neurophysiol 83 (2000) 3537-3547
122. Huyghues-Despointes C.M.J.I., Cope T.C., and Nichols T.R. Intrinsic properties and reflex compensation in reinnervated triceps surae muscles of the cat: effect of activation level. J. Neurophysiol 90 (2003) 1537-1546
123. Hultborn H., and Kiehn O. Neuromodulation of vertebrate motor neuron membrane properties. Curr. Opin. Neurobiol 2 (1992) 770-775
124. Huxley H., and Hanson J. Changes in the cross-striations of muscle during contraction and stretch and their structural interpretation. Nature 173 (1954) 973
125. Huxley A., and Niedergerke R. Structural changes in muscle during contraction. Interference microscopy of living muscle fibres. Nature 173 (1954) 971
126. Irving M., Piazzesi G., Lucii L., Sun Y.B., Harford J.J., Dobbie I.M., Ferenczi M.A., Reconditi M., and Lombardi V. Conformation of the myosin motor during force generation in skeletal muscle. Nat. Struct. Biol 7 (2000) 482-485
127. Jacobs B.L., and Fornal C.A. 5-HT and motor control: a hypothesis. Trends Neurosci 16 (1993) 346-352
128. Jacobs B.L., Martin-Cora F.J., and Fornal C.A. Activity of medullary serotonergic neurons in freely moving animals. Brain Res. Brain Res. Rev 40 (2002) 45-52
129. Jami L., Murthy K.S., Petit J., and Zytnicki D. After-effects of repetitive stimulation at low frequency on fast-contracting motor units of cat muscle. J. Physiol 340 (1983) 129-143
130. Jankowska E. Interneuronal relay in spinal pathways from proprioceptors. Prog. Neurobiol 38 (1992) 335-378
131. Kanda K., and Hashizume K. Factors causing difference in force output among motor units in the rat medial gastrocnemius muscle. J. Physiol 448 (1992) 677-695
132. Kandel E.R., Schwartz J.H., and Jessell T.M. Appleton & Lange. Principles of Neural Science 3rd ed (1991) East Norwalk, CT
133. Kanosue K., Yoshida M., Akazawa K., and Fuji K. The number of active motor units and their firing rates in voluntary contraction of human brachialis muscle. Jap. J. Physiol 29 (1979) 427-444
134. Karlson J. Lactate and phosphagen concentrations in working muscle of man. Acta Physiol. Scand Suppl. (1971) 1-72
135. Katz B., and Miledi R. Propagation of electric activity in motor nerve terminals. Proc. R. Soc. Lond B161 (1965) 453-482
136. Kern D.S., Semmler J.G., and Enoka R.M. Long-term activity in upper- and lower-limb muscles of humans. J. Appl. Physiol 91 (2001) 2224-2232
137. Kernell D. The adaptation and the relation between discharge frequency and current strength of cat lumbosacral motoneurones stimulated by long-lasting injected currents. Acta Physiol. Scand 65 (1965) 65-73
138. Kernell D. High frequency repetitive firing of cat lumbosacral motoneurones stimulated by long-lasting injected currents. Acta Physiol. Scand 65 (1965) 74-86
139. Kernell D. Input resistance, electrical excitability and size of ventral horn cells in cat spinal cord. Science 152 (1966) 1637-1640
140. Kernell D., and Zwaagstra B. Input conductance, axonal conduction velocity and cell size among hindlimb motoneurones of the cat. Brain Res 204 (1981) 311-326
141. Kernell D., and Hensbergen E. Use and fibre type composition in limb muscles of cats. Eur. J. Morphol 36 (1998) 288-292
142. Kernell D., Eerbeek O., and Verhey B.A. Relation between isometric force and stimulus rate in cat's hindlimb motor units of different twitch contraction time. Exp. Brain Res 50 (1983) 220-227
143. Kernell D., Eerbeek O., and Verhey B.A. Motor unit categorization on basis of contractile properties: an experimental analysis of the composition of the cat's m. peroneus longus. Exp. Brain Res 50 (1983) 211-219
144. Kiehn O., and Eken T. Prolonged firing in motor units: evidence of plateau potentials in human motoneurons?. J. Neurophysiol 78 (1997) 3061-3068
145. Kirsch R.F., Boskov D., and Rymer W.Z. Muscle stiffness during transient and continuous movements of cat muscle: perturbation characteristics and physiological relevance. IEEE Trans. Biomed. Engng 41 (1994) 758-770
146. Kudina L.P., and Alexeeva N.L. After-potentials and control of repetitive firing in human motoneurones. Electroencephalogr. Clin. Neurophysiol 85 (1992) 345-353
147. Kugelberg E., and Lindegren B. Transmission and contraction fatigue of rat motor units in relation to succinate dehydrogenase activity of motor unit fibres. J. Physiol 288 (1979) 285-300
148. Kugelberg E., and Thornell L.E. Contraction time, histochemical type, and terminal cisternae volume of rat motor units. Muscle Nerve 6 (1983) 149-153
149. Labeit S., and Kolmerer B. Titins: giant proteins in charge of muscle ultrastructure and elasticity. Science 270 (1995) 293-296
150. Larsson L., Edstrom L., Lindegren B., Gorza L., and Schiaffino S. MHC composition and enzyme-histochemical and physiological properties of a novel fast-twitch motor unit type. Am. J. Physiol 261 (1991) C93-101
151. Lee R.H., and Heckman C.J. Influence of voltage-sensitive dendritic conductances on bistable firing and effective synaptic current in cat spinal motoneurons in vivo. J. Neurophysiol 76 (1996) 2107-2110
152. Lee R.H., and Heckman C.J. Bistability in spinal motoneurons in vivo: systematic variations in persistent inward currents. J. Neurophysiol 80 (1998) 583-593
153. Lee R.H., and Heckman C.J. Paradoxical effect of QX-314 on persistent inward currents and bistable behavior in spinal motoneurons in vivo. J. Neurophysiol 82 (1999) 2518-2527
154. Lee R.H., and Heckman C.J. Enhancement of bistability in spinal motoneurons in vivo by the noradrenergic alpha1 agonist methoxamine. J. Neurophysiol 81 (1999) 2164-2174
155. Lee R.H., and Heckman C.J. Adjustable amplification of synaptic input in the dendrites of spinal motoneurons in vivo. J. Neurosci 20 (2000) 6734-6740
156. Lee R.H., Kuo J.J., Jiang M.C., and Heckman C.J. Influence of active dendritic currents on input-output processing in spinal motoneurons in vivo. J. Neurophysiol 89 (2003) 27-39
157. Li Y., and Bennett D.J. Persistent Sodium and calcium currents cause plateau potentials in motoneurons of chronic spinal rats. J. Neurophysiol 30 (2003) 30
158. Liddell E., and Sherrington C. Recruitment and some other factors of reflex inhibition. Proc. R. Soc. Lond B97 (1925) 488-518
159. Lieber R.L., Shah S., and Friden J. Cytoskeletal disruption after eccentric contraction-induced muscle injury. Clin. Orthop 403 (2002) S90-S99
160. Liversage A.D., Holmes D., Knight P.J., Tskhovrebova L., and Trinick J. Titin and the sarcomere symmetry paradox. J. Mol. Biol 305 (2001) 401-409
161. Lombardi V., and Piazzesi G. The contractile response during lengthening of stimulated frog muscle fibres. J. Physiol 431 (1990) 141-171
162. Macefield V.G., Fuglevand A.J., and Bigland-Ritchie B. Contractile properties of single motor units in human toe extensors assessed by intraneural motor axon stimulation. J. Neurophysiol 75 (1996) 2509-2519
163. Masakado Y., Akaboshi K., Nagata M., Kimura A., and Chino N. Motor unit firing behavior in slow and fast contractions of the first dorsal interosseous muscle of healthy men. Electroencephalogr. Clin. Neurophysiol 97 (1995) 290-295
164. McNulty P.A., Falland K.J., and Macefield V.G. Comparison of contractile properties of single motor units in human intrinsic and extrinsic finger muscles. J. Physiol 526 (2000) 445-456
165. Monster A.W., and Chan H. Isometric force production by motor units of extensor digitorum communis muscle in man. J. Neurophysiol 40 (1977) 1432-1443
166. Moore J.A., and Appenteng K. The morphology and electrical geometry of rat jaw-elevator motoneurones. J. Physiol 440 (1991) 325-343
167. Nemeth P.M., Pette D., and Vrbova G. Comparison of enzyme activities among single muscle fibres within defined motor units. J. Physiol 311 (1981) 489-495
168. Nichols T.R., and Houk J.C. Reflex compensation for variations in the mechanical properties of a muscle. Science 181 (1973) 182-184
169. Nichols T.R., and Houk J.C. Improvement in linearity and regulation of stiffness that results from actions of stretch reflex. J. Neurophysiol 39 (1976) 119-142
170. Olson C., and Swett Jr. C. A functional and histochemical characterization of motor units in a heterogeneous muscle (flexor digitorum longus) of the cat. J. Comp. Neurol 128 (1966) 475-498
171. Perrier J.F., and Hounsgaard J. 5-HT(2) Receptors promote plateau potentials in turtle spinal motoneurons by facilitating an L-type calcium current. J. Neurophysiol 89 (2003) 954-959
172. Perrier J.F., Mejia-Gervacio S., and Hounsgaard J. Facilitation of plateau potentials in turtle motoneurones by a pathway dependent on calcium and calmodulin. J. Physiol 528 (2000) 107-113
173. Person R.S., and Kudina L.P. Discharge frequency and discharge pattern of human motor units during voluntary contraction of muscle. Electroencephalogr. Clin. Neurophysiol 32 (1972) 471-483
174. Petit J., Chua M., and Hunt C.C. Maximum shortening speed of motor units of various types in cat lumbrical muscles. J. Neurophysiol 69 (1993) 442-448
175. Powers R.K., and Binder M.D. Input-output functions of mammalian motoneurons. Rev. Physiol. Biochem. Pharmacol 143 (2001) 137-263
176. Powers R.K., Robinson F.R., Konodi M.A., and Binder M.D. Distribution of rubrospinal synaptic input to cat triceps surae motoneurons. J. Neurophysiol 70 (1993) 1460-1468
177. Rack P.M., and Westbury D.R. The short range stiffness of active mammalian muscle and its effect on mechanical properties. J. Physiol 240 (1974) 331-350
178. Rall W., Burke R.E., Holmes W.R., Jack J.J., Redman S.J., and Segev I. Matching dendritic neuron models to experimental data. Physiol. Rev 72 (1992) S159-S186
179. Rankin L.L., Enoka R.M., Volz K.A., and Stuart D.G. Coexistence of twitch potentiation and tetanic force decline in rat hindlimb muscle. J. Appl. Physiol 65 (1988) 2687-2695
180. Rayment I., Holden H.M., Whittaker M., Yohn C.B., Lorenz M., Holmes K.C., and Milligan R.A. Structure of the actin-myosin complex and its implications for muscle contraction. Science 261 (1993) 58-65
181. Reinking R.M., Stephens J.A., and Stuart D.G. The motor units of cat medial gastrocnemius: problem of their categorisation on the basis of mechanical properties. Exp. Brain Res 23 (1975) 301-313
182. Rekling J.C., Funk G.D., Bayliss D.A., Dong X.W., and Feldman J.L. Synaptic control of motoneuronal excitability. Physiol. Rev 80 (2000) 767-852
183. Rice S.E., Purcell T.J., and Spudich J.A. Building and using optical traps to study properties of molecular motors. Methods Enzymol 361 (2003) 112-133
184. Rivero J.L., Talmadge R.J., and Edgerton V.R. Fibre size and metabolic properties of myosin heavy chain-based fibre types in rat skeletal muscle. J. Muscle Res. Cell Motil 19 (1998) 733-742
185. Romanes G. The motor cell columns of the lumbo-sacral spinal cord of the cat. J. Comp. Neurol 94 (1951) 313-363
186. Rose P.K., and Neuber H.M. Morphology and frequency of axon terminals on the somata, proximal dendrites, and distal dendrites of dorsal neck motoneurons in the cat. J. Comp. Neurol 307 (1991) 259-280
187. Rose P.K., Keirstead S.A., and Vanner S.J. A quantitative analysis of the geometry of cat motoneurons innervating neck and shoulder muscles. J. Comp. Neurol 239 (1985) 89-107
188. Rudy B. Diversity and ubiquity of K channels. Neuroscience 25 (1988) 729-749
189. Sablin E.P., Dawson J.F., VanLoock M.S., Spudich J.A., Egelman E.H., and Fletterick R.J. How does ATP hydrolysis control actin's associations?. Proc. Natl Acad. Sci. USA 99 (2002) 10945-10947
190. Sant'ana Pereira J.A., Wessels A., Nijtmans L., Moorman A.F., and Sargeant A.J. New method for the accurate characterization of single human skeletal muscle fibres demonstrates a relation between mATPase and MyHC expression in pure and hybrid fibre types. J. Muscle Res. Cell Motil 16 (1995) 21-34
191. Schiaffino S., and Reggiani C. Molecular diversity of myofibrillar proteins: gene regulation and functional significance. Physiol. Rev 76 (1996) 371-423
192. Schwindt P.C. Membrane-potential trajectories underlying motoneuron rhythmic firing at high rates. J. Neurophysiol 36 (1973) 434-439
193. Schwindt P.C., and Calvin W.H. Membrane potential trajectories between spikes underlying motoneuron rhythmic firing. J. Neurophysiol 35 (1972) 311-325
194. Schwindt P.C., and Crill W.E. Properties of a persistent inward current in normal and TEA-injected motoneurons. J. Neurophysiol 43 (1980) 1700-1724
195. Semmler J.G., and Nordstrom M.A. Motor unit discharge and force tremor in skill- and strength-trained individuals. Exp. Brain Res 119 (1998) 27-38
196. Seyffarth H. The behaviour of motor units in voluntary contractions. Avhandlinger Utgitt Norske Videnskap-Akap Oslo I Matematisk-Naturvidenskapelig Klasse 4 (1940) 1-63
197. Sherrington C. Remarks on some aspects of reflex inhibition. Proc. R. Soc. Lond B97 (1925) 19-45
198. Shinoda Y., Ohgaki T., Futami T., and Sugiuchi Y. Vestibular projections to the spinal cord: the morphology of single vestibulospinal axons. Prog. Brain Res 76 (1988) 17-27
199. Sieck G.C., Fournier M., Prakash Y.S., and Blanco C.E. Myosin phenotype and SDH enzyme variability among motor unit fibers. J. Appl. Physiol 80 (1996) 2179-2189
200. Siegmund G.P., Inglis J.T., and Sanderson D.J. Startle response of human neck muscles sculpted by readiness to perform ballistic head movements. J. Physiol 535 (2001) 289-300
201. Spiegel K.M., Stratton J., Burke J.R., Glendinning D.S., and Enoka R.M. The influence of age on the assessment of motor unit activation in a human hand muscle. Exp. Physiol 81 (1996) 805-819
202. Staron R.S. Correlation between myofibrillar ATPase activity and myosin heavy chain composition in single human muscle fibers. Histochemistry 96 (1991) 21-24
203. Stephens J.A., and Stuart D.G. The motor units of cat medial gastrocnemius: speed-size relations and their significance for the recruitment order of mortor units. Brain Res 91 (1975) 177-195
204. Stienen G.J., Kiers J.L., Bottinelli R., and Reggiani C. Myofibrillar ATPase activity in skinned human skeletal muscle fibres: fibre type and temperature dependence. J. Physiol 493 (1996) 299-307
205. Stotz P.J., and Bawa P. Motor unit recruitment during lengthening contractions of human wrist flexors. Muscle Nerve 24 (2001) 1535-1541
206. Tam S.L., Archibald V., Tyreman N., and Gordon T. Effect of exercise on stability of chronically enlarged motor units. Muscle Nerve 25 (2002) 359-369
207. Taylor A.M., Christou E.A., and Enoka R.M. Multiple features of motor-unit activity influence force fluctuations during isometric contractions. J. Neurophysiol 90 (2003) 1350-1361
208. Thomas C.K., Ross B.H., and Calancie B. Human motor-unit recruitment during isometric contractions and repeated dynamic movements. J. Neurophysiol 57 (1987) 311-324
209. Thomas C.K., Bigland-Richie B., and Johansson R.S. Force-frequency relationships of human thenar motor units. J. Neurophysiol 65 (1991) 1509-1516
210. Torre M. Nombre et dimensions des unités motrices dans les muscles extrinsèques de l'œil et, in général, dans les muscles squélettiques reliés à des organs de sens. Arch. Suisses Neurol. Psychiary 72 (1953) 362-376
211. Tötösy de Zepetnek J.E., Zung H.V., ErdebiL S., and Gordon T. Innervation ratio is an important determinant of force in normal and reinnervated rat tibialis anterior muscles. J. Neurophysiol 67 (1992) 1385-1403
212. Tyska M.J., and Warshaw D.M. The myosin power stroke. Cell Motil. Cytoskeleton 51 (2002) 1-15
213. Ulfhake B., and Cullheim S. Postnatal development of cat hind limb motoneurons. III: Changes in size of motoneurons supplying the triceps surae muscle. J. Comp. Neurol 278 (1988) 103-120
214. Ulfhake B., and Kellerth J.O. A quantitative morphological study of HRP-labelled cat alpha-motoneurones supplying different hindlimb muscles. Brain Res 264 (1983) 1-19
215. Valls-Solé J., Rothwell J.C., Goulart F., Cossu G., and Munoz E. Patterned ballistic movements triggered by a startle in healthy humans. J. Physiol 516 (1999) 931-938
216. Van Cutsem M., Feiereisen P., Duchateau J., and Hainaut K. Mechanical properties and behaviour of motor units in the tibialis anterior during voluntary contractions. Can. J. Appl. Physiol 22 (1997) 585-597
217. Van Cutsem M., Duchateau J., and Hainaut K. Changes in single motor unit behaviour contribute to the increase in contraction speed after dynamic training in humans. J. Physiol 513 (1998) 295-305
218. Volkmann N., Hanein D., Ouyang G., Trybus K.M., DeRosier D.J., and Lowey S. Evidence for cleft closure in actomyosin upon ADP release. Nat. Struct. Biol 7 (2000) 1147-1155
219. Warren G.L., Ingalls C.P., Lowe D.A., and Armstrong R.B. Excitation-contraction uncoupling: major role in contraction-induced muscle injury. Exerc. Sport Sci. Rev 29 (2001) 82-87
220. Westcott S.L., Powers R.K., Robinson F.R., and Binder M.D. Distribution of vestibulospinal synaptic input to cat triceps surae motoneurons. Exp. Brain Res 107 (1995) 1-8
221. Wuerker R.B., McPhedran A.M., and Henneman E. Properties of motor units in a heterogeneous pale muscle (m. gastrocnemius) in the cat. J. Neurophysiol 28 (1965) 85-99
222. Young V.R., and Scrimshaw N.S. The physiology of starvation. Sci. Am 225 (1971) 14-21
223. Zengel J.E., Reid S.A., Sypert G.W., and Munson J.B. Membrane electrical properties and prediction of motor-unit type of medial gastrocnemius motoneurons in the cat. J. Neurophysiol 53 (1985) 1323-1344