Stability of myosin heavy chain isoforms in selectively denervated adult rat muscle spindles

Wang, Jun; McWhorter, David L.; Walro, Jon M.

doi:10.1002/(sici)1097-0185(199709)249:1<32::aid-ar5>3.0.co;2-h

Cited by 16 publications

(33 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Instead, they were mostly unstained or occasionally stained weakly to moderately, indicating a significant reduction in the My-HC ␣ -c content in the aged nuclear bag 1 and bag 2 fibers. A similar reduction has also been observed in rat nuclear bag 1 fibers after neonatal and adult deefferentation (Pedrosa et al 1990;Walro et al 1997;Wang et al 1997) and in both nuclear bag 1 and bag 2 fibers after a 14-day period of hypogravity (De-Doncker et al 2002). In contrast to the nuclear chain fibers in young adult biceps, some nuclear chain fibers in old muscle spindles showed novel expression of MyHC␣-c isoform.…”

Section: Alterations In Myhc Compositionsupporting

confidence: 74%

Fiber Content and Myosin Heavy Chain Composition of Muscle Spindles in Aged Human Biceps Brachii

Liu

Eriksson

Thornell

et al. 2005

J Histochem Cytochem.

View full text Add to dashboard Cite

Sweden (J-XL,P-OE,L-ET,FP-D)S U M M A R Y The present study investigated potential age-related changes in human muscle spindles with respect to the intrafusal fiber-type content and myosin heavy chain (MyHC) composition in biceps brachii muscle. The total number of intrafusal fibers per spindle decreased significantly with aging, due to a significant reduction in the number of nuclear chain fibers. Nuclear chain fibers in old spindles were short and some showed novel expression of MyHC ␣ -cardiac. The expression of MyHC ␣ -cardiac in bag 1 and bag 2 fibers was greatly decreased in the A region. The expression of slow MyHC was increased in nuclear bag 1 fibers and that of fetal MyHC decreased in bag 2 fibers whereas the patterns of distribution of the remaining MyHC isoforms were generally not affected by aging. We conclude that aging appears to have an important impact on muscle spindle composition. These changes in muscle spindle phenotype may reflect an age-related deterioration in sensory and motor innervation and are likely to have an impact in motor control in the elderly.

show abstract

Section: Alterations In Myhc Compositionsupporting

confidence: 74%

Fiber Content and Myosin Heavy Chain Composition of Muscle Spindles in Aged Human Biceps Brachii

Liu

Eriksson

Thornell

et al. 2005

J Histochem Cytochem.

View full text Add to dashboard Cite

show abstract

“…It is interesting to note that similar myosin heavy chain protein adaptations were found in rats in response to hind-limb unloading [18] and denervation [78,79]. The loss of nuclear chain fibers may impair the static sensitivity of the spindle and ultimately the ability to correctly interpret muscle length [33].…”

Section: Mechanisms Of Proprioception Deterioration With Agingmentioning

confidence: 80%

Aging effects on joint proprioception: the role of physical activity in proprioception preservation

Ribeiro

Oliveira

2007

Eur Rev Aging Phys Act

190

115

View full text Add to dashboard Cite

Throughout the human life span the functions of several physiological systems dramatically change, including proprioception. Impaired proprioception leads to less accurate detection of body position changes increasing the risk of fall, and to abnormal joint biomechanics during functional activities so, over a period of time, degenerative joint disease may result. Altered neuromuscular control of the lower limb and consequently poor balance resulting from changes in the proprioceptive function could be related to the high incidence of harmful falls that occur in old age subjects. There is evidence of proprioception deterioration with aging. Regular physical activity seems to be a beneficial strategy to preserve proprioception and prevent falls among older subjects. Some studies have demonstrated that the regular physical activity can attenuate age-related decline in proprioception. This paper reviews the evidence of age effects on joint proprioception. We will discuss the possible mechanisms behind these effects and the role of regular physical activity in the attenuation of age-related decline in proprioception.

show abstract

“…Typically, muscle spindle quantification has involved cross sections of the spindle capsule through light or electron microscopy (15,(27)(28)(29). This method of visualizing the spindle does not allow for intricate analysis of axon morphology.…”

Section: Discussionmentioning

confidence: 99%

Abnormal Muscle Spindle Innervation and Large-Fiber Neuropathy in Diabetic Mice

et al. 2008

View full text Add to dashboard Cite

OBJECTIVE-Large-fiber diabetic polyneuropathy (DPN) leads to balance and gait abnormalities, placing patients at risk for falls. Large sensory axons innervating muscle spindles provide feedback for balance and gait and, when damaged, can cause altered sensorimotor function. This study aimed to determine whether symptoms of large-fiber DPN in type 1 and type 2 diabetic mouse models are related to alterations in muscle spindle innervation. In addition, diabetic mice were treated with insulin to assess whether sensorimotor and spindle deficits were reversible.RESEARCH DESIGN AND METHODS-Behavioral assessments were performed in untreated and treated streptozotocin (STZ)-injected C57BL/6 mice to quantitate diabetes-induced deficits in balance and gait. Quantification of Ia axon innervation of spindles was carried out using immunohistochemistry and confocal microscopy on STZ-injected C57BL/6 and db/db mice.RESULTS-STZ-injected C57BL/6 mice displayed significant and progressive sensorimotor dysfunction. Analysis of Ia innervation patterns of diabetic C57BL/6 spindles revealed a range of abnormalities suggestive of Ia axon degeneration and/or regeneration. The multiple abnormal Ia fiber morphologies resulted in substantial variability in axonal width and inter-rotational distance (IRD). Likewise, db/db mice displayed significant variability in their IRDs compared with db ϩ mice, suggesting that damage to Ia axons occurs in both type 1 and type 2 diabetes models. Insulin treatment improved behavioral deficits and restored Ia fiber innervation in comparison with nondiabetic mice.CONCLUSIONS-Similar to small fibers, Ia axons are vulnerable to diabetes, and their damage may contribute to balance and gait deficits. In addition, these studies provide a novel method to assay therapeutic interventions designed for diabetes-induced large-fiber dysfunction. Diabetes 57:1693-1701, 2008 E stimates from the Centers for Disease Control and Prevention suggest that 60 -70% of diabetic patients develop neuropathy. In addition, diabetes is the leading cause of neuropathy in the U.S. and Western countries (1). Sensorimotor diabetic polyneuropathy (DPN) affects both large and small sensory afferent nerve fibers. The majority of research focuses on small-fiber neuropathy leading to increased or decreased pain and temperature sensations (2-5). Consequently, there is a shortage of animal model research exploring large-fiber DPN, which can cause deficits in lower-limb proprioception, decreased tactile sensitivity and vibration sense, and incoordination due to balance abnormalities (1,6).The sensorimotor deficits resulting from large-fiber DPN, while sometimes subtle in nature, can lead to significant impairment. Numerous human studies report that patients with DPN are at increased risk for falls due to decreased postural control, altered gait and balance, and increased body sway (7-9). The underlying neurologic mechanisms involved in large-fiber DPN remain poorly understood. It has been hypothesized that large-fiber DPN instability could be ca...

show abstract

Stability of myosin heavy chain isoforms in selectively denervated adult rat muscle spindles

Cited by 16 publications

References 41 publications

Fiber Content and Myosin Heavy Chain Composition of Muscle Spindles in Aged Human Biceps Brachii

Fiber Content and Myosin Heavy Chain Composition of Muscle Spindles in Aged Human Biceps Brachii

Aging effects on joint proprioception: the role of physical activity in proprioception preservation

Abnormal Muscle Spindle Innervation and Large-Fiber Neuropathy in Diabetic Mice

Contact Info

Product

Resources

About