Introduction
Amyotrophic Lateral Sclerosis (ALS) is a devastating and deadly illness that begins with neuromuscular denervation and muscle weak point in adults. These preliminary signs progress quickly to paralysis and demise inside a couple of years. The one FDA-approved therapies for ALS are riluzole and edaravone, which have nominal results on survival.1 Interventions that defend towards denervation of the neuromuscular junction (NMJ) ought to protect muscle perform and enhance survival. Though train is an apparent candidate, its use in ALS has been controversial.2 This factors to the necessity for additional examine in preclinical animal fashions.
Essentially the most extensively used preclinical fashions of ALS are transgenic rodents that specific mutant types of superoxide dismutase.3,4 Mimicking ALS, these animals exhibit a comparatively regular pre-symptomatic stage adopted by muscle weak point, atrophy and eventual paralysis. Additionally like ALS, they exhibit neuromuscular denervation previous to lack of motor neurons.5 Most preclinical analysis into train for ALS has targeted on cardio or endurance train. As within the human literature, preclinical research inspecting the results of train in these fashions report blended outcomes. Reasonable train delayed illness onset and elevated lifespan in a number of research, however high-intensity train hastened illness onset.6–10 Whereas preclinical endurance coaching protocols have nice translational validity, their inherent cardio results introduce disease-modifying confounds.11 Findings from the high-intensity train research are according to accelerated illness development in SOD1-G93A rats following power phrenic nerve hyperstimulation.12 Within the bodily therapeutic context, resistance or power coaching can reverse muscle weak point and is commonly prescribed to people who lack the bodily capability for endurance or cardio train. Like cardio train, the usage of power coaching as an intervention in ALS stays controversial.13
The purpose of the present examine was to find out whether or not long-term resistance train impacts neuromuscular denervation within the SOD1-G93A rat mannequin of ALS. We additionally wished to measure activated (phosphorylated) AMP-Kinase (AMPK). Phosphorylated AMPK (pAMPK) will increase with elevated metabolic demand in cells14 and has been reported to be detrimental within the SOD1-G93A C. elegans mannequin.15 To reply these questions, we used a unilateral forelimb resistance coaching process that enables for within-animal comparisons between muscular tissues within the educated and untrained forelimbs. After operant coaching, rats carried out the duty day by day till they reached illness finish stage.
Experimental Procedures
Animals and Forelimb Coaching
Male SOD1-G93A (n = 6) rats and wildtype (n = 5) littermates had been utilized in our examine. Our protocols had been accepted by the College of Kansas Institutional Animal Care and Use Committee and adhered to the Information for the Care and Use of Laboratory Animals. Rats had been bred in our colony and genotyped by Transnetyx. At roughly 2 months of age, rats had been step by step water restricted and positioned in modified Gerbrands operant chambers for coaching (chambers are described intimately in 16, 17). It ought to be famous that every one rats acquired adequate water to keep away from dehydration (per our animal protocol) and preserve weight achieve all through the experiment till SOD1-G93A rats exhibited disease-related weight reduction. Operant behavioral coaching consisted of shaping rats by means of successive approximations to achieve out of a window within the entrance panel of the chamber with their proper forelimb and press an operandum to lift a water dipper in order that the rat may drink from the dipper cup (Determine 1). As a result of spatial association of the operandum and dipper nicely, power coaching was restricted to the proper forelimb. The operandum (an 18-mm diameter disc rigidly connected to Mannequin 31 load cells; Sensotec) constantly measured the downward power exerted by the forelimb. A LabMaster interface (Scientific Options) acquired the analog indicators from the load cells, transformed the indicators to digital kind, and routed the indicators to a pc. Pc software program recorded the power output at 100 Hz with a power decision of 0.33 g equal weights. The power requirement to lift and preserve the dipper within the raised place was 20 g (ie, the rats licked water whereas they pressed the operandum). When the 0.5 mL dipper cup was depleted, the rat launched its power to refill the dipper and initiated one other press-hold-release bout (Determine 2). After rats efficiently discovered the duty (~13 weeks of age) they engaged in a single 8 min coaching session per day, 5 days/week, for about 3 months (the variety of classes differed as a consequence of heterogeneity in illness development). Coaching classes continued till particular person SOD1-G93A rats exhibited indicators of limb paralysis or now not carried out the duty. Makes an attempt had been made to reap tissue from wildtype rats at the same age as SOD1-G93A rats.
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Determine 1 An SOD1-G93A rat reaching with its proper forelimb to press the operandum (its head is hidden within the cylinder because it drinks water from the dipper cup). The spatial association of the window by means of which the rat reaches, and the dipper ensures use of solely the proper forelimb. The water dipper is raised when the power criterion is exceeded. |
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Determine 2 Uncooked force-time waveforms from a specific 30-s parts of an 8-min resistance coaching session. Power is on the ordinate and time is on the abscissa. The graph illustrates press-hold-release bouts at ~32 and ~54 seconds into the duty. There have been additionally two temporary presses at ~48 and ~52 seconds into the duty. |
Forelimb Power Measures
Information from classes had been analyzed by pc applications that supplied a number of measures of knowledge for every coaching session. The primary measure was one in all total process engagement. Time-on-task, which is analogous to operant response fee, was outlined because the period of time a rat spent making use of at the very least 1 gram of power with its educated forelimb. Following the session, every rat’s uncooked information had been parsed into particular person 4.36 s force-time waveforms recognized by a customized pc program. Particular person waveforms had been averaged for every animal throughout its session. As a result of the primary second of every response sometimes concerned an overshoot of the power requirement (see Determine 2), imply maintain power was a median of the power emitted in the course of the second 3.36 s of the stationary maintain portion of the press-hold-release bouts. To acquire a measure of effort, we calculated time integral of power as the realm underneath the force-time perform. We then calculated force-related tremor (built-in energy) by summing the realm within the energy spectrum between the ten–25 Hz frequency band, as decided by Fourier evaluation of the three.36 s stationary part of the force-time waveforms, as in our earlier research.16,17 The ratio of tremor to power output was additionally calculated to normalize these two associated variables as we’ve discovered this measure to lower with repeated resistance train.18
Tissue Harvest for Morphological Evaluation of Neuromuscular Junctions and Muscle AMPK Protein Ranges
Rats had been anesthetized with isoflurane, and biceps muscular tissues had been dissected bilaterally for NMJ evaluation. Transverse sections taken from the center of the muscle utilizing a cryostat had been 20 µm thick, and the variety of sections essential to quantify at the very least 30 NMJs from every animal was sometimes two to 4. We quantified all of the NMJs discovered on a bit to cut back bias; due to this fact, the variety of NMJs quantified differed barely between animals. This quantification was performed underneath the epi-fluorescence microscope by eye and by focusing up and down the thickness of every recognized NMJ (ie, 2D photographs weren’t used for quantification). Every muscle pattern was analyzed to find out the proportion of innervated, partially denervated and totally denervated neuromuscular junctions in every muscle utilizing immunohistochemical detection of nerves (antibodies towards neurofilament (SMI-312R, Covance) and SV2 (SV2 DSHB)) and acetylcholine receptors (Alexa594-alpha-bungarotoxin, Molecular Probes) as described intimately beforehand.19 Forelimb triceps muscular tissues had been dissected bilaterally for AMPK protein ranges (whole and phosphorylated). Antibodies for pAMPK (T172) and whole AMPK had been bought from Cell Signaling Expertise (Beverly, MA, USA), and protein ranges had been quantified utilizing Western blot detection. Protein ranges of AMPK had been quantified relative to tubulin, whereas pAMPK was quantified relative to whole AMPK.
Statistics
All statistics had been carried out utilizing SYSTAT software program (systat.com). For behavioral variables, significance was assessed by two-way ANOVA with group (SOD1-G93A vs wildtype controls) because the between-subjects issue and time because the within-subjects, repeating issue. For NMJ innervation and AMPK protein analyses, two-way ANOVA with group (SOD1-G93A vs wildtype controls) and aspect (educated vs untrained limb) because the within-subjects, repeating issue. Statistical significance was decided by a p worth ≤0.05.
Outcomes
Process Engagement and Efficiency
Rats in each teams discovered to carry out the duty equally nicely. Physique weight peaked within the SOD1-G93A rats at 19 weeks of age and declined on this group however not within the wildtype rats (Determine 3), resulting in a major group × time interplay (F = 6.145, p < 0.001). Whereas this isn’t a novel discovering in preclinical ALS research, these information are included for reference to the opposite final result measures reported right here. There was a statistically important decline in process engagement (Time on Process) throughout time (F = 3.948; p < 0.05; Determine 4A). Though the decline was pushed primarily by the SOD1-G93A group, neither the group impact nor the interplay impact achieved statistical significance as a consequence of excessive variability within the measure. Likewise, the time integral of power additionally didn’t differ considerably between the 2 teams (Determine 4B). Though this measure declined within the SOD1-G93A rats throughout time, neither the group × time interplay nor the primary impact for time reached statistical significance. Likewise, imply maintain power trended higher for the SOD1-G93A group throughout the three time factors (Determine 5A), however this measure didn’t differ considerably between-groups nor was there an impact of time or a gaggle × time interplay. Though the values had been higher within the wildtype rats on the first two time factors, built-in energy within the 10–25 Hz power band didn’t differ between the 2 teams (Determine 5B), as a perform of time, or within the group × time interplay. Repeated efficiency resulted in a major lower within the ratio of built-in 10–25Hz energy to power (F = 5.379, p < 0.05; Determine 5C). Though the decline on this ratio trended higher within the wildtype rats, the interplay impact didn’t attain statistical significance (p = 0.06). General, the SOD1-G93A rats carried out equally to their wildtype counterparts, even after lack of physique weight, indicating purposeful preservation of their educated forelimbs in the course of the coaching interval. Survival (age in days by which a rat exhibited indicators of limb paralysis or now not carried out the duty) was 162 + 1.4 days in SOD1-G93A rats.
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Determine 3 Physique weight as a perform of age (in weeks) for the wildtype (black circles, n=5) and SOD1-G93A (open circles, n=6) teams. Rats had been educated to carry out the duty previous to week 13 and continued day by day power coaching by means of their twenty third week. ***Group × time interplay, p<0.001; *First time level at which teams differed considerably as decided by t-test. |
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Determine 4 Time on process (A) and time integral of power (B) as a perform of time (4 months, 5 months, closing session) in wildtype (n=5; black circles) and SOD1-G93A rats (n=6 open circles). Time on process declined throughout the classes. Though this was pushed primarily by the SOD1-G93A group, neither the primary impact for group nor the group by time interplay achieved statistical significance. Though time integral of power declined throughout time within the SOD1-G93A rats, this measure didn’t differ considerably between-groups, as a perform of time, or within the group × time interplay. *Primary impact for time, p<0.05. |
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Determine 5 Imply power (A), built-in energy within the 10–25 Hz band (B), and the ratio of 10–25 Hz energy to power (C) as a perform of group and time (n=5 WT; n=6 SOD1-G93A). Neither power nor 10–25 Hz energy differed considerably as a perform of group or time. The ratio of 10–25 Hz energy to power did decline considerably as a perform time. Though this was pushed by the wildtype group, there was not a major impact of group or group by time interplay. *Primary impact for time, p<0.05. |
NMJ Innervation
Immunohistochemistry of NMJs from an untrained vs educated biceps muscle in an SOD1-G93A rat is proven in Determine 6. Overlap of the nerve and receptor signifies full innervation, whereas lack of overlap signifies a denervated receptor because of the nerve dying again. Forelimb biceps muscle denervation was considerably higher within the SOD1-G93A group than within the wildtype group (F = 25.353, p = 0.001). Forelimb coaching had a major impact on this measure, as the proportion of fully-intervated NMJs was considerably higher within the educated (proper) than within the untrained (left) biceps muscular tissues (F = 8.830, p < 0.05). There was a major group × aspect interplay, because the coaching impact was higher within the SOD1-G93A group (who exhibited denervation of their untrained forelimbs) than within the wildtype group (F = 6.773, p < 0.05). The extent of this safety was current even within the faster-progressing rats that had higher denervation of their untrained forelimbs.
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Determine 6 Energy coaching protected towards NMJ denervation in biceps of SOD1-G93A rats. (A) Epi-fluorescence microscopy photographs of consultant forelimb biceps NMJs from an SOD1-G93A rat (rows present 2 photographs per forelimb). NMJs had been detected utilizing antibodies towards neurofilament and SV2 (nerve; inexperienced) and α-bungarotoxin (acetylcholine receptors; pink). Pictures are for illustration. Quantification was accomplished by focusing by means of the 3D construction of the NMJ as described within the Strategies. Discover the overlap of the nerve and receptor within the educated muscle (indicated full innervation) and the dearth of overlap within the untrained muscle (the nerve has died again, and the receptor is denervated). (B) Wildtype rats exhibited higher NMJ innervation than SOD1-G93A rats. Resistance coaching had little impact on NMJ innervation in the proper (educated) vs left (untrained) biceps within the wildtype rats (n=5) however protected towards denervation within the educated biceps within the SOD1-G93A rats (n=6). *Group × aspect interplay, p=0.05. |
AMPK Activation
Western blot analyses revealed that pAMPK was higher within the educated forelimb triceps from SOD1-G93A rats however not within the wildtype rats, resulting in a major group × aspect (educated vs untrained limb) interplay (F = 7.514, p < 0.05; see Determine 7). This impact remained important even when the outlier information level from the educated SOD1-G93A rat (see Determine 6) was eliminated (F = 7.400, p < 0.05).
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Determine 7 Energy coaching resulted in higher pAMPK ranges in triceps muscular tissues of SOD1-G93A rats, however not wildtype rats. (A) Consultant blots exhibiting pAMPK, whole AMPK, and tubulin ranges in left (L; untrained) and proper (R; educated) limbs of two wildtype (rat B07 and B08) and two SOD1-G93A rats (rat B01 and rat B02). (B) Educated muscular tissues in SOD1-G93A rats exhibited higher activated AMPK (pAMPK). *Group × aspect interplay, p<0.05. |
Dialogue
We report right here that unilateral resistance train protects towards forelimb muscle weak point and NMJ denervation in SOD1-G93A rats. SOD1-G93A rats had been capable of carry out the forelimb train process even when their untrained forelimb reached the purpose of paralysis. This purposeful and neuroprotective impact coincided with higher AMPK activation within the educated forelimb muscular tissues of SOD1-G93A rats. These outcomes assist resistance train as a remedy for muscle weak point in ALS, and a doubtlessly optimistic position for muscle AMPK activation on this impact.
Earlier research testing cardio train in animal fashions of ALS report dose-dependent results. Reasonable depth train has been reported to delay illness onset and elevated lifespan, whereas high-intensity train hastened illness onset.6–8,10 If the results of cardio train generalize to resistance train, our outcomes recommend that the power necessities we applied had been of average depth. This might be according to the power of Sprague-Dawley rats to supply forces exceeding 60 g on this process.18 Alternatively, it’s attainable that the detrimental results of high-intensity cardio train don’t happen with resistance train. Additional research evaluating the mobile results of train on this mannequin as a perform of train modality are essential to check this speculation.
The optimistic results of resistance train on forelimb power and NMJ safety reported right here distinction with our latest examine inspecting tongue power coaching in SOD1-G93A rats.20 In comparison with unexercised controls, ALS rats that had been required to lick a force-sensing disc with increased forces exhibited related (~50%) NMJ denervation of their genioglossus muscle and earlier tongue motility deficits. Whereas speculative, it’s attainable that variations between limb and tongue muscular tissues, as reported by others within the context of growing old21,22 accounted for this impact. In contrast to the tongue, limb muscular tissues connect to bones on each ends. This relationship shouldn’t be merely mechanical, nevertheless. Each muscle and bone act as endocrine organs that secrete proteins that affect one another by means of a posh bone-muscle crosstalk (reviewed in23). Additional research are wanted to find out the extent to which mechanical vs secretory components could account for variations between these muscle teams.
The etiology of ALS is unknown, however muscle use and train have lengthy been implicated as disease-facilitating components.24–30 These findings contribute to the controversy concerning train in ALS. Elevated incidence in athletes and higher signs within the dominant limbs of affected people assist the muscle use speculation. The muscle use speculation is almost inconceivable to check in people, precluding testing symptom onset as an final result measure in a managed experiment. In retrospective research, confounding variables similar to trauma and publicity to toxins complicate interpretations of causality.26,31 Choice bias in case–management research or recall accuracy in retrospective research additionally impacts interpretation. Our outcomes don’t assist the muscle use speculation in ALS illness development, at the very least for the SOD1-G93A familial type of ALS.
One mechanism by which muscle exercise would possibly affect neuromuscular illness processes in ALS is thru enhanced mobile bioenergetics. Regardless of impaired muscle mitochondrial perform,32 elevated metabolism has been reported each in SOD1 transgenic fashions of ALS33,34 and in sporadic ALS.35,36 The truth that muscle contraction will increase muscle metabolic exercise means that power coaching may exacerbate hypermetabolism and speed up neuromuscular dysfunction in ALS. This speculation is supported by two latest research involving AMPK, a sensor for mobile power stability that’s activated underneath situations of metabolic/ATP demand.37 The primary examine discovered that reducing AMPK exercise improves motor perform in SOD1-G93A C. elegans (sadly, muscle denervation was not measured on this examine).15 One other examine reported that power AMPK stimulation impairs adaptive signaling in dystrophic skeletal muscle.38 Our outcomes, nevertheless, reveal a optimistic relationship between AMPK activation and NMJ preservation, at the very least in muscle tissue. On the group stage, higher pAMPK ranges accompanied higher NMJ innervation within the educated forelimb muscular tissues of SOD1-G93A rats in comparison with decrease pAMPK and NMJ innervation of their untrained forelimbs. Our findings are according to a latest examine reporting that AMPK activation through carbamazepine resulted within the safety of NMJs and motor neurons and prolonged survival in ALS SOD1-G93A mice.39 Additional research inspecting cell-specific (muscle vs neuronal) adjustments in AMPK activation are wanted to deal with this controversy.
Our findings of a resistance coaching impact on the ratio of force-related tremor to power output are according to our earlier examine in wholesome grownup rats.18 Though the interplay between group and time didn’t attain statistical significance, the decline on this ratio trended higher in wholesome controls. Isometric force-related tremor is a neurophysiological course of associated to motor neuron recruitment.40–42 Though this course of will be modified by train and could also be disrupted in ALS, the dearth of a statistical important interplay means that each teams exhibited this coaching impact. This phenomenon was not the first measure on this examine, and extra research with adequately powered teams are required to research the results of ALS on training-related neuromuscular perform.
Conclusions
Our outcomes assist the usage of resistance train to guard towards muscle weak point and illness development in ALS. The proportion of fully-intervated NMJs within the triceps of SOD1-G93A rats following repeated resistance train was similar to that of interventions that embody medication, stem cells, gene silencing, and neurotrophic components, in SOD1-G93A fashions.39,43–49 The truth that there stays ~25% room for additional safety means that combining resistance train with different interventions could improve neuromuscular safety and survival. We acknowledge a number of weaknesses of our examine and caveats related to our findings. The shortage of a sedentary management group is a weak point for 2 causes: we can not rule out systematic laterality concerning NMJ denervation nor can we decide results of our intervention on survival. Though paralysis onset is commonly noticed in a single limb in animal fashions of ALS, there are not any information to our data on laterality variations (a lot much less systematic variations) in NMJ denervation in ALS. In actual fact, the muscle use speculation would predict higher denervation in educated forelimbs. Concerning survival, it’s unlikely that defending NMJ innervation in a single forelimb would produce an impact, as evidenced by the truth that our rats survived a median of 162 days. Future checks implementing whole-body resistance train protocols are essential to find out an impact on survival. By limiting our deal with NMJ denervation, we could have missed results of resistance train on motor neurons within the spinal wire. Though the results on motor neuron quantity might not be as obvious within the spinal wire given the “dying again” nature of degeneration in ALS,5 that is an empirical query that might be worthwhile to deal with. One other weak point is that we didn’t embody feminine rats. That is additionally a future purpose because the intervention could also be extra useful if feminine rats exhibit a distinct illness time course and severity. Lastly, as in most preclinical ALS research, we used SOD1 mutant rodents to mannequin the illness. As we be taught extra about totally different subtypes of ALS, e.g.,50 interventions will probably be tailor-made to sufferers based mostly on their distinctive genetic background. General, our distinctive unilateral forelimb resistance train process will permit for managed preclinical testing in rodent fashions of ALS.
Acknowledgments
This work was supported by NIH grants GM103418, HD57850, NS078214, AG026491, AG031575, HD02528, and a KUMC Biomedical Analysis Coaching grant. The authors gratefully acknowledge the contributions of the late Stephen C. Fowler, PhD, in whose laboratory the isometric forelimb resistance train process originated.
Disclosure
Dr Hiroshi Nishimune stories grants from NIH in the course of the conduct of the examine. The authors report no conflicts of curiosity on this work.
References
1. Jaiswal MK. Riluzole and edaravone: a story of two amyotrophic lateral sclerosis medication. Med Res Rev. 2019;39(2):733–748. Cited in: PMID: 30101496. doi:10.1002/med.21528
2. Tsitkanou S, Della Gatta P, Foletta V, Russell A. The position of train as a non-pharmacological therapeutic strategy for amyotrophic lateral sclerosis: useful or detrimental? Entrance Neurol. 2019;10:783. Cited in: PMID: 31379732; PMCID: PMC6652799. doi:10.3389/fneur.2019.00783
3. Gurney ME, Pu H, Chiu AY, et al. Motor neuron degeneration in mice that specific a human Cu, Zn superoxide dismutase mutation. Science. 1994;264(5166):1772–1775. Erratum in: Science 1995 Jul 14;269(5221):149. PMID: 8209258. doi:10.1126/science.8209258
4. Nagai M, Aoki M, Miyoshi I, et al. Rats expressing human cytosolic copper-zinc superoxide dismutase transgenes with amyotrophic lateral sclerosis: related mutations develop motor neuron illness. J Neurosci. 2001;21(23):9246–9254. PMID: 11717358; PMCID: PMC6763929. doi:10.1523/JNEUROSCI.21-23-09246.2001
5. Fischer LR, Culver DG, Tennant P, et al. Amyotrophic lateral sclerosis is a distal axonopathy: proof in mice and man. Exp Neurol. 2004;185(2):232–240. PMID: 14736504. doi:10.1016/j.expneurol.2003.10.004
6. Kirkinezos IG, Hernandez D, Bradley WG, Moraes CT. Common train is useful to a mouse mannequin of amyotrophic lateral sclerosis. Ann Neurol. 2003;53(6):804–807. PMID: 12783429. doi:10.1002/ana.10597
7. Veldink JH, Bär PR, Joosten EA, Otten M, Wokke JH, van den Berg LH. Sexual variations in onset of illness and response to train in a transgenic mannequin of ALS. Neuromuscul Disord. 2003;13(9):737–743. PMID: 14561497. doi:10.1016/s0960-8966(03)00104-4
8. Mahoney DJ, Rodriguez C, Devries M, Yasuda N, Tarnopolsky MA. Results of high-intensity endurance train coaching within the G93A mouse mannequin of amyotrophic lateral sclerosis. Muscle Nerve. 2004;29(5):656–662. PMID: 15116368. doi:10.1002/mus.20004
9. Kaspar BK, Frost LM, Christian L, Umapathi P, Gage FH. Synergy of insulin-like development factor-1 and train in amyotrophic lateral sclerosis. Ann Neurol. 2005;57(5):649–655. PMID: 15852403. doi:10.1002/ana.20451
10. Carreras I, Yuruker S, Aytan N, et al. Reasonable train delays the motor efficiency decline in a transgenic mannequin of ALS. Mind Res. 2010;1313:192–201. PMID: 19968977; PMCID: PMC2892864. doi:10.1016/j.brainres.2009.11.051
11. Um HS, Kang EB, Leem YH, et al. Train coaching acts as a therapeutic technique for discount of the pathogenic phenotypes for Alzheimer’s illness in an NSE/APPsw-transgenic mannequin. Int J Mol Med. 2008;22(4):529–539. PMID: 18813861.
12. Lepore AC, Tolmie C, O’Donnell J, et al. Peripheral hyperstimulation alters web site of illness onset and course in SOD1 rats. Neurobiol Dis. 2010;39(3):252–264. PMID: 20381620; PMCID: PMC2910141. doi:10.1016/j.nbd.2010.03.021
13. Patel BP, Hamadeh MJ. Dietary and exercise-based interventions within the remedy of amyotrophic lateral sclerosis. Clin Nutr. 2009;28(6):604–617. PMID: 19782443. doi:10.1016/j.clnu.2009.06.002
14. Kjøbsted R, Hingst JR, Fentz J, et al. AMPK in skeletal muscle perform and metabolism. FASEB J. 2018;32(4):1741–1777. PMID: 29242278; PMCID: PMC5945561. doi:10.1096/fj.201700442R
15. Lim MA, Selak MA, Xiang Z, et al. Decreased exercise of AMP-activated protein kinase protects towards genetic fashions of motor neuron illness. J Neurosci. 2012;32(3):1123–1141. PMID: 22262909; PMCID: PMC3742882. doi:10.1523/JNEUROSCI.6554-10.2012
16. Stanford JA, Fowler SC. Dantrolene diminishes forelimb force-related tremor at doses that don’t lower operant habits within the rat. Exp Clin Psychopharmacol. 2002;10(4):385–391. PMID: 12498335. doi:10.1037//1064-1297.10.4.385
17. Bethel-Brown CS, Morris JK, Stanford JA. Younger and middle-aged rats exhibit isometric forelimb power management deficits in a mannequin of early-stage Parkinson’s illness. Behav Mind Res. 2011;225(1):97–103. PMID: 21767573; PMCID: PMC3178104. doi:10.1016/j.bbr.2011.07.002
18. Stanford JA, Vorontsova E, Fowler SC. The connection between isometric power requirement and forelimb tremor within the rat. Physiol Behav. 2000;69(3):285–293. PMID: 10869594. doi:10.1016/s0031-9384(99)00248-6
19. Smittkamp SE, Spalding HN, Brown JW, et al. Measures of bulbar and spinal motor perform, muscle innervation, and mitochondrial perform in ALS rats. Behav Mind Res. 2010;211(1):48–57. PMID: 20211206; PMCID: PMC2872192. doi:10.1016/j.bbr.2010.03.007
20. Ma D, Shuler JM, Kumar A, et al. Results of tongue power coaching on bulbar motor perform within the feminine SOD1-G93A rat mannequin of amyotrophic lateral sclerosis. Neurorehabil Neural Restore. 2017;31(2):147–156. PMID: 27573800; PMCID: PMC5243852. doi:10.1177/1545968316666956
21. Connor NP, Ota F, Nagai H, Russell JA, Leverson G. Variations in age-related alterations in muscle contraction properties in rat tongue and hindlimb. J Speech Lang Hear Res. 2008;51(4):818–827. PMID: 18658053; PMCID: PMC2892886. doi:10.1044/1092-4388(2008/059)
22. Kletzien H, Russell JA, Leverson GE, Connor NP. Differential results of focused tongue train and treadmill operating on growing old tongue muscle construction and contractile properties. J Appl Physiol. 2013;114(4):472–481. PMID: 23264540; PMCID: PMC3568981. doi:10.1152/japplphysiol.01370.2012
23. Bonewald L. Use it or lose it to age: a evaluation of bone and muscle communication. Bone. 2019;120:212–218. PMID: 30408611; PMCID: PMC6360108. doi:10.1016/j.bone.2018.11.002
24. McMenemey WH. Pathological points. Proc R Soc Med. 1962;55(12):1032–1033. PMID: 13932193; PMCID: PMC1897528.
25. Felmus MT, Patten BM, Swanke L. Antecedent occasions in amyotrophic lateral sclerosis. Neurology. 1976;26(2):167–172. PMID: 946326. doi:10.1212/wnl.26.2.167
26. Harwood CA, McDermott CJ, Shaw PJ. Bodily exercise as an exogenous danger consider motor neuron illness (MND): a evaluation of the proof. Amyotroph Lateral Scler. 2009;10(4):191–204. PMID: 19263258. doi:10.1080/17482960802549739
27. Beghi E, Logroscino G, Chiò A, et al. Amyotrophic lateral sclerosis, bodily train, trauma and sports activities: outcomes of a population-based pilot case-control examine. Amyotroph Lateral Scler. 2010;11(3):289–292. PMID: 20433412; PMCID: PMC3513269. doi:10.3109/17482960903384283
28. Turner MR, Wicks P, Brownstein CA, et al. Concordance between web site of onset and limb dominance in amyotrophic lateral sclerosis. J Neurol Neurosurg Psychiatry. 2011;82(8):853–854. PMID: 20562391. doi:10.1136/jnnp.2010.208413
29. Raymond J, Mehta P, Larson T, Issue-Litvak P, Davis B, Horton Okay. Historical past of vigorous leisure-time bodily exercise and early onset amyotrophic lateral sclerosis (ALS), information from the nationwide ALS registry: 2010–2018. Amyotroph Lateral Scler Frontotemporal Degener. 2021;24:1–10. PMID: 33896281. doi:10.1080/21678421.2021.1910308
30. Chiò A, Benzi G, Dossena M, Mutani R, Mora G. Severely elevated danger of amyotrophic lateral sclerosis amongst Italian skilled soccer gamers. Mind. 2005;128(Pt 3):472–476. PMID: 15634730. doi:10.1093/mind/awh373
31. Armon C. Sports activities and trauma in amyotrophic lateral sclerosis revisited. J Neurol Sci. 2007;262(1–2):45–53. PMID: 17681549. doi:10.1016/j.jns.2007.06.021
32. Duffy LM, Chapman AL, Shaw PJ, Grierson AJ. Overview: the position of mitochondria within the pathogenesis of amyotrophic lateral sclerosis. Neuropathol Appl Neurobiol. 2011;37(4):336–352. PMID: 21299590. doi:10.1111/j.1365-2990.2011.01166.x
33. Dupuis L, Oudart H, René F, de Aguilar JL G, Loeffler JP. Proof for faulty power homeostasis in amyotrophic lateral sclerosis: advantage of a high-energy eating regimen in a transgenic mouse mannequin. Proc Natl Acad Sci U S A. 2004;101(30):11159–11164. PMID: 15263088; PMCID: PMC503756. doi:10.1073/pnas.0402026101
34. Dupuis L, Loeffler JP. Neuromuscular junction destruction throughout amyotrophic lateral sclerosis: insights from transgenic fashions. Curr Opin Pharmacol. 2009;9(3):341–346. PMID: 19386549. doi:10.1016/j.coph.2009.03.007
35. Desport JC, Preux PM, Magy L, et al. Elements correlated with hypermetabolism in sufferers with amyotrophic lateral sclerosis. Am J Clin Nutr. 2001;74(3):328–334. PMID: 11522556. doi:10.1093/ajcn/74.3.328
36. Desport JC, Torny F, Lacoste M, Preux PM, Couratier P. Hypermetabolism in ALS: correlations with scientific and paraclinical parameters. Neurodegener Dis. 2005;2(3–4):202–207. PMID: 16909026. doi:10.1159/000089626
37. Hayashi T, Hirshman MF, Fujii N, Habinowski SA, Witters LA, Goodyear LJ. Metabolic stress and altered glucose transport: activation of AMP-activated protein kinase as a unifying coupling mechanism. Diabetes. 2000;49(4):527–531. PMID: 10871188. doi:10.2337/diabetes.49.4.527
38. Ljubicic V, Khogali S, Renaud JM, Jasmin BJ. Continual AMPK stimulation attenuates adaptive signaling in dystrophic skeletal muscle. Am J Physiol Cell Physiol. 2012;302(1):C110–21. PMID: 21940670. doi:10.1152/ajpcell.00183.2011
39. Zhang JJ, Zhou QM, Chen S, Le WD. Repurposing carbamazepine for the remedy of amyotrophic lateral sclerosis in SOD1-G93A mouse mannequin. CNS Neurosci Ther. 2018;24(12):1163–1174. PMID: 29656576; PMCID: PMC6489874. doi:10.1111/cns.12855
40. Allum JH, Dietz V, Freund HJ. Neuronal mechanisms underlying physiological tremor. J Neurophysiol. 1978;41(3):557–571. PMID: 660226. doi:10.1152/jn.1978.41.3.557
41. Hömberg V, Reiners Okay, Hefter H, Freund HJ. The muscle exercise spectrum: spectral evaluation of muscle power as an estimator of total motor unit exercise. Electroencephalogr Clin Neurophysiol. 1986;63(3):209–222. PMID: 2419077. doi:10.1016/0013-4694(86)90087-8
42. McAuley JH, Rothwell JC, Marsden CD. Frequency peaks of tremor, muscle vibration and electromyographic exercise at 10 Hz, 20 Hz and 40 Hz throughout human finger muscle contraction could mirror rhythmicities of central neural firing. Exp Mind Res. 1997;114(3):525–541. PMID: 9187289. doi:10.1007/pl00005662
43. Kalmar B, Edet-Amana E, Greensmith L. Therapy with a coinducer of the warmth shock response delays muscle denervation within the SOD1-G93A mouse mannequin of amyotrophic lateral sclerosis. Amyotroph Lateral Scler. 2012;13(4):378–392. PMID: 22591194. doi:10.3109/17482968.2012.660953
44. Pérez-García MJ, Burden SJ. Growing MuSK exercise delays denervation and improves motor perform in ALS mice. Cell Rep. 2012;2(3):497–502. PMID: 22939980; PMCID: PMC3462266. doi:10.1016/j.celrep.2012.08.004
45. Yoo YE, Ko CP. Dihydrotestosterone ameliorates degeneration in muscle, axons and motoneurons and improves motor perform in amyotrophic lateral sclerosis mannequin mice. PLoS One. 2012;7(5):e37258. PMID: 22606355; PMCID: PMC3351454. doi:10.1371/journal.pone.0037258
46. Krakora D, Mulcrone P, Meyer M, et al. Synergistic results of GDNF and VEGF on lifespan and illness development in a familial ALS rat mannequin. Mol Ther. 2013;21(8):1602–1610. PMID: 23712039; PMCID: PMC3734670. doi:10.1038/mt.2013.108
47. Thomsen GM, Gowing G, Latter J, et al. Delayed illness onset and prolonged survival within the SOD1G93A rat mannequin of amyotrophic lateral sclerosis after suppression of mutant SOD1 within the motor cortex. J Neurosci. 2014;34(47):15587–15600. PMID: 25411487; PMCID: PMC4298650. doi:10.1523/JNEUROSCI.2037-14.2014
48. Dadon-Nachum M, Ben-Yaacov Okay, Ben-Zur T, et al. Transplanted modified muscle progenitor cells expressing a combination of neurotrophic components delay illness onset and improve survival within the SOD1 mouse mannequin of ALS. J Mol Neurosci. 2015;55(3):788–797. PMID: 25330859. doi:10.1007/s12031-014-0426-0
49. Nizzardo M, Bucchia M, Ramirez A, et al. iPSC-derived LewisX+CXCR4+β1-integrin+ neural stem cells enhance the amyotrophic lateral sclerosis phenotype by preserving motor neurons and muscle innervation in human and rodent fashions. Hum Mol Genet. 2016;25(15):3152–3163. PMID: 27270413. doi:10.1093/hmg/ddw163
50. Pampalakis G, Angelis G, Zingkou E, Vekrellis Okay, Sotiropoulou G. A chemogenomic strategy is required for efficient remedy of amyotrophic lateral sclerosis. Clin Transl Med. 2022;12(1):e657. PMID: 35064780; PMCID: PMC8783349. doi:10.1002/ctm2.657
