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Histochemical and immunohistochemical study on muscle fibers in human extraocular muscle spindles.
Exp Eye Res. 2007 Apr; 84(4):670-9.EE

Abstract

Human extraocular muscles are unique in several ways including their endowment with proprioceptive organs. Aim of this study was to establish a classification of intrafusal muscle fibers of human extraocular muscles based on their histochemical and immunohistochemical properties and to determine their relationship to extrafusal extraocular muscle fiber types in this respect. Using light microscopy, intrafusal muscle fibers were followed on consecutive cross-sections and classified according to the localization of their myonuclei and to their enzyme- and myosin-immunohistochemical characteristics. Sixteen muscle spindles in human extraocular muscles counted as 'true' spindles revealed 27% nuclear chain fibers [40.1 microm+/-10.4; perimeter+/-SD] and 73% anomalous fibers [44.1 microm+/-12]. Seven 'false' muscle spindles showed only anomalous fibers [43.8 microm+/-11.1] and entirely lacked nuclear chain fibers. Six fiber types were distinguished according to their histochemical and myosin heavy chain immunohistochemical properties. Fiber type 1 [46.3 microm+/-13.3] was made up of fast-twitch myosin heavy chain isoform. Fiber type 2 [39.5 microm+/-10] additionally expressed a developmental myosin heavy chain isoform. Fiber type 3 [42.8 microm+/-10.4] consisted of pure slow-twitch positive muscle fibers. Slow-twitch MHC and fast-twitch myosin heavy chain isoform were found in fiber type 4 [43.3 microm+/-9]. Fiber types 5 and 6 showed different myosin heavy chain patterns than fiber types 1-4. The vast majority of nuclear chain fibers displayed fiber type 2 features, but 12% of nuclear chain fibers were found to be of fiber type 1. Among anomalous fibers in true spindles the frequency of fiber type 1 was much higher than in false spindles. On the other hand, fiber type 4 was found more often in false than in true spindles. With regard to their histochemical and immunohistochemical properties intrafusal muscle fibers in human extraocular muscles differ both from intrafusal muscle fibers in other skeletal muscles and from extrafusal muscle fibers in extraocular eye muscles. These conspicuous differences to skeletal muscle spindles relate to their morphology and myosin heavy chain characteristics. In particular, the occurrence of anomalous fibers might reflect dynamic neuronal processes and might be necessary for modulating and adapting processes in advancing age, as well as maintaining proprioceptive input during the whole life.

Authors+Show Affiliations

Medical University of Vienna, Center of Anatomy and Cell Biology, Integrative Morphology Group, Waehringer Stasse 13, 1090 Vienna, and Institute of Pathology and Bacteriology, Kaiserin Elisabeth Hospital, Austria. waltraut.wicke@meduniwien.ac.atNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

17270173

Citation

Wicke, Waltraut, et al. "Histochemical and Immunohistochemical Study On Muscle Fibers in Human Extraocular Muscle Spindles." Experimental Eye Research, vol. 84, no. 4, 2007, pp. 670-9.
Wicke W, Wasicky R, Brugger PC, et al. Histochemical and immunohistochemical study on muscle fibers in human extraocular muscle spindles. Exp Eye Res. 2007;84(4):670-9.
Wicke, W., Wasicky, R., Brugger, P. C., Kaminski, S., & Lukas, J. R. (2007). Histochemical and immunohistochemical study on muscle fibers in human extraocular muscle spindles. Experimental Eye Research, 84(4), 670-9.
Wicke W, et al. Histochemical and Immunohistochemical Study On Muscle Fibers in Human Extraocular Muscle Spindles. Exp Eye Res. 2007;84(4):670-9. PubMed PMID: 17270173.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Histochemical and immunohistochemical study on muscle fibers in human extraocular muscle spindles. AU - Wicke,Waltraut, AU - Wasicky,Richard, AU - Brugger,Peter C, AU - Kaminski,Stephan, AU - Lukas,Julius R, Y1 - 2007/01/30/ PY - 2006/08/03/received PY - 2006/11/10/revised PY - 2006/12/04/accepted PY - 2007/2/3/pubmed PY - 2007/5/19/medline PY - 2007/2/3/entrez SP - 670 EP - 9 JF - Experimental eye research JO - Exp Eye Res VL - 84 IS - 4 N2 - Human extraocular muscles are unique in several ways including their endowment with proprioceptive organs. Aim of this study was to establish a classification of intrafusal muscle fibers of human extraocular muscles based on their histochemical and immunohistochemical properties and to determine their relationship to extrafusal extraocular muscle fiber types in this respect. Using light microscopy, intrafusal muscle fibers were followed on consecutive cross-sections and classified according to the localization of their myonuclei and to their enzyme- and myosin-immunohistochemical characteristics. Sixteen muscle spindles in human extraocular muscles counted as 'true' spindles revealed 27% nuclear chain fibers [40.1 microm+/-10.4; perimeter+/-SD] and 73% anomalous fibers [44.1 microm+/-12]. Seven 'false' muscle spindles showed only anomalous fibers [43.8 microm+/-11.1] and entirely lacked nuclear chain fibers. Six fiber types were distinguished according to their histochemical and myosin heavy chain immunohistochemical properties. Fiber type 1 [46.3 microm+/-13.3] was made up of fast-twitch myosin heavy chain isoform. Fiber type 2 [39.5 microm+/-10] additionally expressed a developmental myosin heavy chain isoform. Fiber type 3 [42.8 microm+/-10.4] consisted of pure slow-twitch positive muscle fibers. Slow-twitch MHC and fast-twitch myosin heavy chain isoform were found in fiber type 4 [43.3 microm+/-9]. Fiber types 5 and 6 showed different myosin heavy chain patterns than fiber types 1-4. The vast majority of nuclear chain fibers displayed fiber type 2 features, but 12% of nuclear chain fibers were found to be of fiber type 1. Among anomalous fibers in true spindles the frequency of fiber type 1 was much higher than in false spindles. On the other hand, fiber type 4 was found more often in false than in true spindles. With regard to their histochemical and immunohistochemical properties intrafusal muscle fibers in human extraocular muscles differ both from intrafusal muscle fibers in other skeletal muscles and from extrafusal muscle fibers in extraocular eye muscles. These conspicuous differences to skeletal muscle spindles relate to their morphology and myosin heavy chain characteristics. In particular, the occurrence of anomalous fibers might reflect dynamic neuronal processes and might be necessary for modulating and adapting processes in advancing age, as well as maintaining proprioceptive input during the whole life. SN - 0014-4835 UR - https://www.unboundmedicine.com/medline/citation/17270173/Histochemical_and_immunohistochemical_study_on_muscle_fibers_in_human_extraocular_muscle_spindles_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0014-4835(06)00461-1 DB - PRIME DP - Unbound Medicine ER -