ライフサイエンスコーパス: motor unit

1 racked MUs) and 1.5 (group of all identified motor units).

2 ps of current and the force developed by its motor unit.

3 tatory synaptic drive required to activate a motor unit.

4 ry and sufficient for proper function of the motor unit.

5 ntraction speed, or the tetanic force of the motor unit.

6 stimulation of single motor axons to thenar motor units.

7 nic and intermittent) as observed for the 53 motor units.

8 ate the significant and rapid fatigue of the motor units.

9 rential recruitment of separately innervated motor units.

10 that there is no somatotopic organization of motor units.

11 uscles with pattern that mimic fast and slow motor units.

12 s nerve regeneration and restores functional motor units.

13 ng and were thus considered to form anatomic motor units.

14 t of sphincter function and the formation of motor units.

15 slow SOL (200 pulses at 20 Hz every 30 sec) motor units.

16 cruitment pattern of slow versus fast-twitch motor units.

17 n produced, but also by the number of active motor units.

18 tion of the instantaneous frequencies of the motor units.

19 contractile measures of primate extraocular motor units.

20 AP while recording force produced by failing motor units.

21 n generated by tetanic stimulation of single motor units.

22 se, by preventing fully fused contraction of motor units.

23 rons and the contractile properties of their motor units.

24 rather than on rate modulation of individual motor units.

25 d contraction was lower for the intermittent motor units (11.0 +/- 3.3 pulses s(-1)) than the tonic m

26 s (11.0 +/- 3.3 pulses s(-1)) than the tonic motor units (13.7 +/- 3.3 pulses s(-1); P = 0.005), and

27 d from equivalent decreases in the number of motor units, 16% smaller than the adult value of ninety-

28 motor units (34.6 +/- 12.3%) than the tonic motor units (21.2 +/- 9.4%) at recruitment (P = 0.001) a

29 ike interval was higher for the intermittent motor units (34.6 +/- 12.3%) than the tonic motor units

30 tromyography recordings were decomposed into motor unit action potentials to examine the neural drive

31 G signals were decomposed into discharges of motor unit action potentials.

32 Firing patterns typical of slow motor units activate genes for slow isoforms of contract

33 scribe the behavior of muscles as a group of motor units activated by voluntary effort.

34 er degree of movement difficulty, and unique motor unit activation pattern associated with maximal-le

35 Multiple factors, including motor unit activation patterns, muscle fibre contractile

36 t sensations (paraesthesiae) or asynchronous motor-unit activation (fasciculation) that result from a

37 record the concurrent activity of only a few motor units active during a muscle contraction.

38 rt-term synchronisation of left and right EI motor unit activity and significant coherence between le

39 t be explained by a prolonged suppression of motor unit activity at the spinal level.

40 ier was developed and used to evoke perioral motor unit activity during non-nutritive suck in preterm

41 Needle electromyography revealed continuous motor unit activity in the 50- to 70-Hz frequency during

42 Here, we report the temporal patterning of motor unit activity in the soleus muscle of awake, behav

43 lation to various standard measures of human motor unit activity such as short-term synchronization.

44 Single motor unit activity was recorded with intramuscular elec

45 rgies based on partial coherence analysis of motor unit activity.

46 ch task involved the recruitment of perioral motor units against an elastic load.

47 n and a decrease in the number of functional motor units, all relevant to the clinical presentation o

48 unction, muscle contractile characteristics, motor unit and motor neuron survival.

49 nce between the recruitment threshold of the motor unit and the target force for the sustained contra

50 rence between the recruitment threshold of a motor unit and the target force of the sustained contrac

51 s, and it associates with both a heavy chain motor unit and tubulin located within the A-tubule of th

52 s of motor neurons, enlargement of surviving motor units and instability of neuromuscular junction tr

53 tractile characteristics, loss of functional motor units and motor neuron degeneration.

54 The 4DL muscles contained between 4 and 9 motor units and motor unit sizes ranged in distribution

55 contribute to failed postnatal maturation of motor units and muscle weakness.

56 Sv2a gene permits selective labeling of slow motor units and reveals their composition.

57 rce and contractile characteristics, rescued motor units and, importantly, improved motor neuron surv

58 either the recruitment of additional muscle motor units and/or the progressive recruitment of less e

59 o serially examine the number of regenerated motor units, and binomial statistics were used to compar

60 The age-related remodelling of motor units appeared to involve denervation of fast musc

61 sciculations, axonal conduction block in the motor unit arborization and of variable axonal conductio

62 Two standard tests for the evaluation of the motor unit are nerve conduction studies/electromyography

63 bules and lead to a model for how individual motor units are controlled within the outer dynein arm.

64 Hand motor units are not readily categorized into the classic

65 le neurons or, alternatively, whether entire motor units are of one type or the other.

66 for muscle control is that large, fatigable motor units are preferentially recruited before smaller

67 ressive decline in the muscle force at which motor units are recruited during repeated voluntary cont

68 As motor units are recruited, signals that direct blood flo

69 plays an important role in establishing how motor units are recruited.

70 dings challenge the classical concept of the motor unit as an anatomically distinct and functionally

71 ficantly alters the functional output of the motor unit as measured with compound muscle action poten

72 ction failure and by optimizing the input to motor units as their contractile properties change.

73 ustained contraction on the discharge of the motor unit at recruitment.

74 Common drive to motor units at frequencies of < 4 Hz was assessed by cro

75 ograde influences in order to understand how motor units become homogeneous.

76 ns of low SMN will give insight into why the motor unit becomes dysfunctional.

77 f sibling neurites within single fluorescent motor units, both during development and during regenera

78 discharged in association with two different motor units, but were blocked or delayed whenever the tw

79 for the gradation of the force produced by a motor unit by rate modulation.

80 We conclude that restoration of functional motor units by embryonic stem cells is possible and repr

81 are preferentially recruited before smaller motor units by the lowest-intensity electrical cuff stim

82 ntation of confocal image projections of 4DL motor units, by applying high resolution (63x, 1.4 NA ob

83 maximal voluntary effort, assuming that all motor units can be recruited voluntarily.

84 the probability that as few as two to three motor units can deviate the eye 1 degrees.

85 It has been suggested that neonatal motor units cannot increase in size because they are alr

86 s assembly of actin into a functional myosin motor unit capable of generating force.

87 Motor unit coherence analysis was used to characterize t

88 Furthermore, the amount of motor unit coherence in the low-frequency band (2-12 Hz)

89 m to yield subparticles containing different motor unit combinations and assess the microtubule-bindi

90 Motor units comprise a pre-synaptic motor neuron and mul

91 unctions inhere to RqlH-(1-505), a monomeric motor unit comprising the ATPase, linker and zinc-bindin

92 Recording from single human motor units confirmed the role of the 'carrier frequency

93 pared with the rostral band, suggesting that motor units conforming to a Fast Synapsing (FaSyn) pheno

94 Here we performed image analysis of motor unit connectivity in the fourth deep lumbrical mus

95 Surprisingly, these large motor units contained few if any degenerating synapses.

96 Many movement disorders disrupt motor unit contractile dynamics and the structure of sar

97 sarcomere displacements, we monitored single motor unit contractions in soleus and vastus lateralis m

98 (1) Motor units could be categorized based on contraction sp

99 wed that the twitch force and EMG of failing motor units could be significantly increased by 4AP, whe

100 For all muscles studied, neighboring motor units could have significantly different best dire

101 trophy (SMA), and aging, fast-fatigable (FF) motor units degenerate early, whereas motor neurons inne

102 g occurred in FR units, whereas the S and FF motor units demonstrated dramatic, but opposing, changes

103 t a constant frequency of 100 Hz, 95% of the motor units demonstrated significantly different force l

104 The core structure of the dynein motor unit derives from the assembly of six AAA domains

105 We showed that the motor unit developed nearly its maximal force during the

106 ("primary range") up to the point where the motor unit develops its maximal force.

107 average discharge rate for the intermittent motor units did not change across 211 +/- 153 s of inter

108 Motor unit discharge rates decline by about 50 % over 60

109 but were blocked or delayed whenever the two motor units discharged within a few milliseconds of one

110 a, and EMG doublet or multiplet ('myokymic') motor unit discharges, indicated that an autoantibody-me

111 B, n = 18) of doublet or multiplet myokymic motor unit discharges.

112 lucosylceramide, to neurodegeneration and to motor unit dismantling in amyotrophic lateral sclerosis

113 Diagnosis of motor unit disorders involves the history, physical exam

114 Organ-specific autoantibodies in motor unit disorders with weakness occur in myasthenia g

115 e identification of specific immune-mediated motor unit disorders.

116 or synchrony in the efficient recruitment of motor units during maintained grip.

117 the initial cellular events that precipitate motor unit dysfunction and loss remain poorly characteri

118 arge frequency and variability of individual motor units, each spike train was divided into 2-15 equa

119 gotes), we demonstrated previously that many motor units exhibit functional deficits that likely refl

120 Each motor unit exhibited the two discharge patterns (tonic a

121 f synaptic consolidation enhanced functional motor unit expansion in the absence of presynaptic NCAM.

122 We found up to twice the number of motor units expected by random regeneration in direct su

123 iological analyses, our results suggest that motor unit failure is due to failure of neuromuscular sy

124 re, we developed a phenomenological model of motor unit fatigue as a tractable means to predict muscl

125 he potential utility of the model to predict motor unit fatigue for more complicated, real-world appl

126 Hz range oscillatory activity, but also from motor unit firing properties, mechanical resonances and

127 and antagonist muscles caused by involuntary motor-unit firing at rest are the hallmark clinical and

128 adult value of ninety-seven, and in the mean motor unit Fo value, 14% less than the adult value of 11

129 in motoneuronal firing necessary to increase motor unit force by 1.0 mg) of the units correlated with

130 rats greatly improved repetitive firing and motor unit force generation.

131 In rapidly contracting "twitch" muscles, motor unit force is believed to be primarily determined

132 Mean motor unit force was also significantly larger with nife

133 ereas no effect was observed in a nonfailing motor unit from a symptomless, aged-matched HCSMA animal

134 within circumscribed regions of the muscle, motor units from GDNF injected animals had significantly

135 Antiparkinsonian medication releases motor units from the 10-Hz synchronizing influence, enab

136 ial trains (MUPTs) contributed by individual motor units from the composite EMG signals.

137 The procedure involves connecting the motor unit (frontalis muscle) and the upper eyelid.

138 ATP hydrolysis by the BchID motor unit fuels the insertion of Mg(2+) into the porphy

139 denervation on postnatal day 14 (P14), when motor units have decreased to their adult size, motoneur

140 unting for this striking specificity, termed motor unit homogeneity, remain incompletely understood,

141 Some small motor units, however, no longer possessed any neuromuscu

142 We computed the firing instants of motor units identified from intramuscular EMGs detected

143 t assignment of axon terminals to identified motor units imaged at lower optical resolution (40x, 1.3

144 ose previously reported for an intact dynein motor unit in the absence of ATP, suggesting that it res

145 ded from the whole muscles and from a single motor unit in the muscle.

146 scharge times were obtained from 23 pairs of motor units in 14 subjects to assess the strength of mot

147 The discharge characteristics of 53 motor units in biceps brachii were recorded after being

148 actile abnormalities, the loss of functional motor units in EDL muscles and delayed end-stage disease

149 train; range, 100-782 spikes) from 26 single motor units in extensor hallucis longus during sustained

150 emonstrate that the force outputs of failing motor units in HCSMA homozygotes can be increased by 4AP

151 males may be subserved by two populations of motor units in males that can be distinguished by the st

152 rmined for MGN muscles and eighty-two single motor units in muscles of adult (10-12 months) and sixty

153 lies on the recruitment and derecruitment of motor units in response to the oscillatory descending dr

154 the recruitment of PMNs and consequently, of motor units in the diaphragm.

155 cruitment and derecruitment forces of single motor units in the human extensor digitorum and tibialis

156 Motor units in the ipsilateral PSP were significantly co

157 tween these afferents and the recruitment of motor units in the lower face during the dynamics of spe

158 erence was caused by the presence of failing motor units in the muscles from homozygotes was tested d

159 ny body pattern components may have multiple motor units in the optic lobe and that these are organiz

160 ntractions of single and groups of in-series motor units in the peroneus tertius muscle of the cat hi

161 t biological tool to understand formation of motor units in vitro and a potential therapeutic tool to

162 The motor unit includes the anterior horn cell, the motor ax

163 ained constant, but the number of fibres per motor unit increased 3-fold from 57 to 165.

164 c development in either vulnerable or stable motor units, indicating that abnormal pre-symptomatic de

165 the CNS control the activation of individual motor units, individual muscles, groups of muscles, kine

166 The dynamic function of the molecular motor units inside the supramolecular assemblies was stu

167 Proper function of the motor unit is dependent upon the correct development of

168 a decrease in the fatigue resistance of the motor units is unknown.

169 The result is the synchronous discharge of motor units leading to rhythmic jerking.

170 ort-term synchrony was measured for pairs of motor units located within and across muscles activated

171 motor systems of the brain, spinal cord, and motor unit make functional use of new circuitry feasible

172 e the contractile properties of human thenar motor units more than paralysis alone.

173 signals were decomposed into the constituent motor unit (MU) action potential trains.

174 We recorded whole muscle and single motor unit (MU) activities in healthy adults performing

175 A motor unit (MU) coherence analysis was used to capture t

176 TRACT: During graded isometric contractions, motor unit (MU) firing rates increase steeply upon recru

177 During graded isometric contractions, motor unit (MU) firing rates increase steeply upon recru

178 omuscular structure and function in terms of motor unit (MU) number, size and MU potential (MUP) stab

179 KEY POINTS: Classic motor unit (MU) recording and analysis methods do not al

180 ol of muscle is realized at the level of the motor unit (MU), it seems important to consider the phys

181 ALS is characterized by a motor unit (MU)-dependent vulnerability where MNs with f

182 w method is proposed for tracking individual motor units (MUs) across multiple experimental sessions

183 Some motor units (n = 22) discharged action potentials tonica

184 G) and force were recorded from 17 paralysed motor units (n = 7 subjects) in response to intraneural

185 Significantly more paralysed motor units need to be excited during patterned electric

186 tients, muscle weakness, CMAP amplitudes and motor unit number estimates correlated with clinical dis

187 decline in muscle strength, vital capacity, motor unit number estimates, ALS Functional Rating Scale

188 ty, ALS Functional Rating Scale-Revised, and motor unit number estimates.

189 cular atrophy (SMA) 1, 2, and 3 subjects via motor unit number estimation (MUNE) and maximum compound

190 hology, we developed an electrophysiological motor unit number estimation (MUNE) assay to measure the

191 compound muscle action potential (CMAP) and motor unit number estimation (MUNE), as in human SMA.

192 Motor unit number estimation was decreased by about half

193 ed with compound muscle action potential and motor unit number estimation.

194 with clinical measures, electrophysiological motor unit number index (MUNIX) and T2-weighted whole-bo

195 Motor Unit Number Index (MUNIX) is a novel neurophysiolo

196 (b) nifedipine treatment on force output and motor unit numbers.

197 een this 45 kDa axonemal polypeptide and the motor unit of the gamma HC.

198 ecreased by 34% and the number of fibres per motor unit of the remaining units decreased to 86% of th

199 Interspike interval distributions from human motor units of a variety of muscles were analysed to ass

200 This stalk-length dependency suggests that motor units of the spasmoneme may be organized in such a

201 t previously been thought to show segregated motor unit organisation.

202 Motor unit pairs in the ipsilateral FDI showed significa

203 was to determine the fatigability of thenar motor units paralysed chronically (10 +/- 2 years) by ce

204 rinatal lethality, decreased motor function, motor unit pathology, and hyperexcitable MNs.

205 ed that mismatched connections in developing motor units possibly become weak early (by 8 days postna

206 assessed quantitative parameters related to motor unit potential (MUP) morphology derived from elect

207 automated software (DQEMG), which extracted motor unit potential trains (MUPTs) contributed by indiv

208 The loss of motor axons and changes to motor unit potential transmission precede a clinically-r

209 Out of a total of 301 motor unit potentials identified, 23 potentials exhibite

210 rve stimulation that each electrode recorded motor unit potentials innervated by different axons.

211 Given the dispersed arrangement of motor units, precise matching of flow to metabolism is n

212 ontrol with microbial opsins, recruitment of motor units proceeds in the physiological recruitment se

213 ities in the understanding of adjustments in motor unit properties due to training interventions or t

214 Paralysed motor unit properties were independent of injury duratio

215 in ATP requirements of the already recruited motor units rather than to changes in the recruitment pa

216 d scientific advantages compared with single motor units recorded from intramuscular electrodes.

217 rams were constructed from the discharges of motor units recorded from the long and short abductor mu

218 Pairs of discharges of single motor units recorded in the same or different muscles of

219 ole-cell recordings, was reduced, and single motor unit recordings in awake, behaving neonates showed

220 itive contractions) elicits a high degree of motor unit recruitment and muscle fiber stimulation.

221 Exercise onset entails motor unit recruitment and the initiation of vasodilatat

222 ndicated by multiple independent measures of motor unit recruitment including conduction latency, con

223 The effect of motor unit recruitment on functional vasodilatation was

224 In voluntary activation the heterogeneous motor unit recruitment together with immediate motion tr

225 e to rhythmic contractions is facilitated by motor unit recruitment.

226 y (40 Hz), DTI in all vessels increased with motor unit recruitment.

227 e of this study was to determine the role of motor unit remodelling in the deficit that develops in t

228 With ageing, little motor unit remodelling occurred in FR units, whereas the

229 al intercostal nerve branches, EMG sites and motor units reported in a companion paper.

230 rief review, basic contractile properties of motor units residing in human hand muscles are described

231 Surprisingly, synchrony for pairs of motor units residing in separate muscles (flexor pollici

232 We propose to call such complexes 'regulated motor units' (RMU).

233 Despite the motor unit's centrality to neuromuscular physiology, no

234 Motor units serve both as the mechanical apparatus and t

235 Reconstruction of entire motor units showed that some were abnormally large.

236 th that generates a territorial hierarchy in motor unit size and disposition.

237 lost due to the partial denervation because motor unit size did not change.

238 of the motor innervation was removed because motor unit size increased by 2.5 times.

239 or units, which correlated weakly with their motor unit size.

240 suboptimal wiring length and distribution of motor unit size.

241 es contained between 4 and 9 motor units and motor unit sizes ranged in distribution from 3 to 111 mo

242 Motor unit sizes were estimated from tetanic tensions an

243 In anaesthetized dogs, multiunit and single motor unit (SMU) EMG activity was monitored in the dorsa

244 y and coherence between discharges of single motor units (SMUs) in the first dorsal interosseous (1DI

245 s tuning is subserved at the level of single motor units (SMUs).

246 e amelioration of neuronal histopathology in motor units such as spinal motor neurons, neuromuscular

247 ies and organization of the neural inputs to motor units supplying finger muscles is essential for un

248 ase, resulting in increased muscle force and motor unit survival and a significant increase in motor

249 its in 14 subjects to assess the strength of motor unit synchronisation and coherence during the thre

250 This study examined the strength of motor unit synchronisation based on time- and frequency-

251 t motoneurone pools results in both abnormal motor unit synchronisation between left and right EMGs a

252 The strength of motor unit synchronisation was approximately 50 % greate

253 healthy subjects did not reveal evidence of motor unit synchronization.

254 ian duration of 37 ms, indicating broad-peak motor unit synchronization.

255 ius (MG) muscle of homozygous HCSMA animals, motor unit tetanic failure is apparent before the appear

256 were surprised to observe that, at ages when motor unit tetanic failure is common, the structure of n

257 These observations suggest that the motor unit tetanic failure observed in the MG muscle in

258 With paralysis and baclofen, the median motor unit tetanic forces were significantly weaker, twi

259 ordings of a substantially greater number of motor units than with conventional methods.

260 hat binds to other subunits and a C-terminal motor unit that contains six AAA (ATPase associated with

261 ests the likely domain rearrangements of the motor unit that generate its power stroke.

262 small mammals mainly relies on the number of motor units that are recruited rather than on rate modul

263 roduced by continuous, involuntary firing of motor units that is thought to be caused by an autoimmun

264 Large amplitude motor units that provide large tensions were the most se

265 of brain circuits, from sensory receptors to motor units, that are involved in control of this behavi

266 By examining the activity of individual motor units (the muscle fibers innervated by a single mo

267 For a motor unit to function, neurons and muscle cells need to

268 cleotide-independent manner and tethers this motor unit to the A-tubule of the outer doublet microtub

269 and offer insight into the failure of young motor units to expand after partial denervation.

270 Counts of motor units to the soleus muscle as well as of axons in

271 hanges occur in ALS-vulnerable TMNs based on motor unit type and discharge characteristics.

272 per animal (total = 22), each identified by motor unit type and located near the site of afferent in

273 onal changes suggest a shift toward a slower motor unit type.

274 the disease progression as a function of the motor unit type.

275 The effects of different motor unit types, time-dependent brain effort, sources o

276 d the sensitivity was the same for different motor unit types.

277 ective impact of SMN depletion on the distal motor unit using a series of SMN2-expressing transgenic

278 Diseases of the motor unit usually present with weakness.

279 Each motor unit was situated in the homologous muscle on eith

280 To investigate the force production of mouse motor units, we simultaneously recorded, for the first t

281 Greater motor unit weakness with long-term baclofen use and para

282 Data from three groups of motor units were compared: 23 paralysed units from spina

283 Surprisingly, however, small motor units were confined to a region of the muscle near

284 Several structural properties of the motor units were consistent with those reported in other

285 The two groups of motor units were distinguished by the difference between

286 During an unfused tetanus, fast and slow (S) motor units were identified by the presence and absence

287 e patterns of up to 12 simultaneously active motor units were identified from each signal using compu

288 The discharges of two motor units were identified in an intrinsic hand muscle

289 In an additional experiment, 12 motor units were recorded at two different target forces

290 Some motor units were recruited in both inspiratory and expir

291 Groups of three motor units were stimulated isotonically at low rates (a

292 nd that the recruitment thresholds of single motor units were unchanged during repeated contractions,

293 to consider the physiological properties of motor units when attempting to understand and predict mu

294 Results from 66 motor units (whereof 31 from gastrocnemius) revealed the

295 nces in variance of motor endplate length in motor units, which correlated weakly with their motor un

296 sented as the pooled spike trains of several motor units, which provides an accurate representation o

297 The results suggest that newly recruited motor units with recruitment thresholds closer to the ta

298 tials at more regular and greater rates than motor units with recruitment thresholds further from the

299 o compare the observed number of regenerated motor units with that expected if axonal regeneration of

300 tead, many of these components have multiple motor units within the optic lobe and are organized in a