An exceptionally high density of muscle spindles in a slow‐tonic pigeon muscle

Rosser, Benjamin W. C.; George, J. C.

doi:10.1002/ar.1092120203

Cited by 17 publications

(11 citation statements)

References 25 publications

(29 reference statements)

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“…A correlation between avian muscle fiber histochemistry and muscle function has been described previously (e.g., Simpson, 1979;Maier, 1983;Rosser and George, 1985;Welsford et al, 1991;Meyers, 1992aMeyers, , 1993Sokoloff et al, 1998), in that muscles thought to be used for activities such as locomotion have greater proportions of fast-twitch fibers, and muscles thought to have a postural role have higher proportions of slow fibers. Extensive studies of various birds (Rosser and George, 1986a,b;Rosser et al, 1994), indicated that a number of taxa possess slow-contracting muscle fibers presumed to function in posture, gliding flight, or underwater swimming.…”

supporting

confidence: 52%

Anatomy and histochemistry of spread‐wing posture in birds. 3. Immunohistochemistry of flight muscles and the “shoulder lock” in albatrosses

Meyers

Stakebake

2004

Journal of Morphology

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As a postural behavior, gliding and soaring flight in birds requires less energy than flapping flight. Slow tonic and slow twitch muscle fibers are specialized for sustained contraction with high fatigue resistance and are typically found in muscles associated with posture. Albatrosses are the elite of avian gliders; as such, we wanted to learn how their musculoskeletal system enables them to maintain spread-wing posture for prolonged gliding bouts. We used dissection and immunohistochemistry to evaluate muscle function for gliding flight in Laysan and Black-footed albatrosses. Albatrosses possess a locking mechanism at the shoulder composed of a tendinous sheet that extends from origin to insertion throughout the length of the deep layer of the pectoralis muscle. This fascial "strut" passively maintains horizontal wing orientation during gliding and soaring flight. A number of muscles, which likely facilitate gliding posture, are composed exclusively of slow fibers. These include Mm. coracobrachialis cranialis, extensor metacarpi radialis dorsalis, and deep pectoralis. In addition, a number of other muscles, including triceps scapularis, triceps humeralis, supracoracoideus, and extensor metacarpi radialis ventralis, were found to have populations of slow fibers. We believe that this extensive suite of uniformly slow muscles is associated with sustained gliding and is unique to birds that glide and soar for extended periods. These findings suggest that albatrosses utilize a combination of slow muscle fibers and a rigid limiting tendon for maintaining a prolonged, gliding posture.

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supporting

confidence: 52%

Anatomy and histochemistry of spread‐wing posture in birds. 3. Immunohistochemistry of flight muscles and the “shoulder lock” in albatrosses

Meyers

Stakebake

2004

Journal of Morphology

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“…A muscle spindle index of 503 makes the tenuissimus of the hamster one of the most densely-populated muscles yet studied. Previously, the highest spindle index recorded for a mammalian muscle was 460 for a single cat intervertebral centrotransverse muscle (Bakker and Richmond, 1982), although Rosser and George (1985) have reported an unusually high spindle index of 14,582 in the M. coracotriceps of the pigeon. In addition, both of these groups have demonstrated the existence of a high number of tandomlylinked spindle units in these spindle-rich muscles.…”

Section: Muscle Spindle Densitymentioning

confidence: 93%

“…In addition, both of these groups have demonstrated the existence of a high number of tandomlylinked spindle units in these spindle-rich muscles. Rosser and George (1985) further point out that the tiny and specialized M. coracotriceps may act as a highly sensitive mechanoreceptor capable of regulating or modifying the activity of neighboring muscles. Whether the tenuissimus plays a similar role is uncertain, although Lev-Tov and co-workers (1988) suggest that the delicacy, small cross-sectional area, and min-imal force-output capacity of the muscle preclude any significant contribution to overall movement about the hip and knee.…”

Section: Muscle Spindle Densitymentioning

confidence: 95%

Morphometry and histoenzymology of the hamster tenuissimus and its muscle spindles

Patten

Ovalle

1992

Anat. Rec.

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Muscle spindles and extrafusal fibers in the tenuissimus muscle of mature golden Syrian hamsters were studied morphologically and quantitatively using several light microscopic techniques. Muscle spindles were identified in serial-transverse frozen-sections of whole muscles stained with hematoxylin and eosin. Five tenuissimus muscles were examined from origin to insertion, and the locations of individual receptors were plotted in camera-lucida reconstructions. Spindles were found in proximity to the main neurovascular bundle in the central core of each muscle. A range of 16-20 receptors was noted per muscle. The mean muscle spindle index (the total number of spindles per gram of muscle weight) was 503 and the average spindle length was 7.5 mm. Oxidative enzyme and myosin adenosine-triphosphatase (ATPase) staining profiles were also evaluated in the intrafusal and extrafusal fibers in each muscle. Even numbers of type I and type IIA extrafusal fibers were distributed homogeneously throughout all muscle cross-sections. Histochemical staining patterns varied along the lengths of the three intrafusal fiber types. Nuclear chain fibers possessed staining properties similar to the type IIA extrafusal fibers and exhibited no regional variations. Bag1 fibers displayed staining variability, particularly when treated for myosin ATPase under acid preincubation conditions. Some spindles were isolated under darkfield illumination and then either treated with 7-nitrobenz-2-oxa-1,3-diazole (NBD)-phallacidin to detect filamentous actin by fluorescence microscopy, or prepared for conventional scanning electron microscopy (SEM). By fluorescence microscopy, a registered actin banding-pattern was observed in the sarcomeres of the intrafusal fibers, and variations in the intensity of banding were noted amongst different fibers. SEM revealed punctate sensory nerve endings that adhered intimately to the surfaces of underlying intrafusal fibers in the equatorial and juxtaequatorial regions. By transmission electron microscopy (TEM) these endings appeared crescent-shaped and were enveloped by external laminae. Each profile contained numerous mitochondria and cytoskeletal organelles. The high spindle density observed in this muscle suggests that the hamster tenuissimus may function in hindlimb proprioception.

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“…High muscle spindle density coupled with a low extrafusal fiber number suggests a sensory feedback and fine movement adjustment priority for that muscle, perhaps working in a "parallel muscle combination" (PMC) with a larger, more powerful muscle which is more responsible for gross movement [15,101]. Rosser and George proposed that the coracotriceps muscle of the pigeon similarly regulates larger shoulder muscle activation [110]. Muscles of the horse shoulder (articularis humeri) [82] and hip (articularis coxae) [75] are believed to provide the sensory feedback which enables larger, more powerful limb muscles to function in a highly coordinated manner.…”

Section: Parallel Muscle Combinationsmentioning

confidence: 99%

The human glenohumeral joint

Nyland

Caborn

Johnson

1998

Knee Surgery, Sports Traumatology, Arthroscopy

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The glenohumeral joint, because of its relatively poor osseous and capsuloligamentous stability, depends upon the proprioceptive and stabilizing capabilities of musculotendinous structures more than any other joint in the human body. The purpose of this review is to compare the morphology, histology, and sensorimotor functional relationships of the human glenohumeral joint with the more abundant animal research data. From a synthesis of this information, a proprioceptive and stability alliance is proposed for the human glenohumeral joint which is initiated by mechanoreceptor activation from capsuloligamentous and musculotendinous structures, resulting in reflex-mediated protective muscular responses that are ultimately under the bias and sensitivity control of upper levels of the central nervous system hierarchy. The clinical impact of these findings as they relate to rehabilitation and conditioning strategies, surgical intervention, aging, and injury are discussed in addition to future research directions.

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An exceptionally high density of muscle spindles in a slow‐tonic pigeon muscle

Cited by 17 publications

References 25 publications

Anatomy and histochemistry of spread‐wing posture in birds. 3. Immunohistochemistry of flight muscles and the “shoulder lock” in albatrosses

Anatomy and histochemistry of spread‐wing posture in birds. 3. Immunohistochemistry of flight muscles and the “shoulder lock” in albatrosses

Morphometry and histoenzymology of the hamster tenuissimus and its muscle spindles

The human glenohumeral joint

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