Motoneuronal innervation and mechanical properties of extraocular muscles in the catfish, (<i>Ictalurus punctatus</i>)

Lennerstrand, Gunnar; Baker, R.

doi:10.1111/j.1748-1716.1987.tb08251.x

Cited by 8 publications

(8 citation statements)

References 24 publications

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“…Despite the details that are known of the anatomic organization of the eye muscle, it is not known how these structural features contribute to eye movements (Lennerstrand and Baker, 1987). The function of the palisade endings is unclear, and they are at present the subject of controversy, with some reports claiming them as sensory structures and others describing motor-like properties .…”

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confidence: 99%

Motoneurons of twitch and nontwitch extraocular muscle fibers in the abducens, trochlear, and oculomotor nuclei of monkeys

Büttner‐Ennever

Horn

Scherberger

et al. 2001

J of Comparative Neurology

144

193

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Eye muscle fibers can be divided into two categories: nontwitch, multiply innervated muscle fibers (MIFs), and twitch, singly innervated muscle fibers (SIFs). We investigated the location of motoneurons supplying SIFs and MIFs in the six extraocular muscles of monkeys. Injections of retrograde tracers into eye muscles were placed either centrally, within the central SIF endplate zone; in an intermediate zone, outside the SIF endplate zone, targeting MIF endplates along the length of muscle fiber; or distally, into the myotendinous junction containing palisade endings. Central injections labeled large motoneurons within the abducens, trochlear or oculomotor nucleus, and smaller motoneurons lying mainly around the periphery of the motor nuclei. Intermediate injections labeled some large motoneurons within the motor nuclei but also labeled many peripheral motoneurons. Distal injections labeled small and medium-large peripheral neurons strongly and almost exclusively. The peripheral neurons labeled from the lateral rectus muscle surround the medial half of the abducens nucleus: from superior oblique, they form a cap over the dorsal trochlear nucleus; from inferior oblique and superior rectus, they are scattered bilaterally around the midline, between the oculomotor nucleus; from both medial and inferior rectus, they lie mainly in the C-group, on the dorsomedial border of oculomotor nucleus. In the medial rectus distal injections, a "C-group extension" extended up to the Edinger-Westphal nucleus and labeled dendrites within the supraoculomotor area. We conclude that large motoneurons within the motor nuclei innervate twitch fibers, whereas smaller motoneurons around the periphery innervate nontwitch, MIF fibers. The peripheral subgroups also contain medium-large neurons which may be associated with the palisade endings of global MIFs. The role of MIFs in eye movements is unclear, but the concept of a final common pathway must now be reconsidered.

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Motoneurons of twitch and nontwitch extraocular muscle fibers in the abducens, trochlear, and oculomotor nuclei of monkeys

Büttner‐Ennever

Horn

Scherberger

et al. 2001

J of Comparative Neurology

144

193

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“…This would be contrary to that of the gudgeon, carpet shark, and butterflyfish with centrally located white fibers, with red fibers toward the periphery (Kordylewski, ; Housley and Montgomery, ; Bauchot et al, ). Although different fiber types are known to exist in fish extraocular muscles it is believed that all fiber types are recruited for all types of eye movement (Lennerstrand and Baker, ). The inclusion of slow twitch fibers in the model would affect the results, as the specific tensions of elasmobranch slow twitch and fast twitch fibers are very different at 14.2 N/cm2 and 28.9 N/cm 2 , respectively (Lou et al, ).…”

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confidence: 99%

“…Electrically stimulating the extraocular muscles produced maximum tetanic tensions in 15-25 cm total length catfish (Ictaturus punctatus) that ranged from 0.03 N (inferior oblique) to 0.02 N (medial rectus) (Lennerstrand and Baker, 1987). To maintain fixation of the eye, Collins et al (1975Collins et al ( , 1981 recorded maximum tension of the medial and lateral recti muscles of the human eye with mean values of 0.73 N and 0.58 N, respectively, and with peak values as high as 1.0 N, during saccadic eye movement.…”

Section: Discussionmentioning

confidence: 99%

“…In situ calculations of the tetanic forces exerted by human extraocular muscles range from 0.49 N to 0.67 N (Scott and Collins, 1973;Collins et al, 1981;Lennerstrand et al, 2009). Additionally, the physiology and histology of extraocular muscles has been examined in several vertebrates including chickens, fish, frogs, rats, and monkeys (Kilarsky and Bigaj, 1969;Pachter, 1982;Lennerstrand and Baker, 1987;Frueh et al, 2000;Shall and Dimitrova, 2003;Croes and Bartheld, 2007). However, no one, to the best of our knowledge, has calculated the torques exerted by individual extraocular muscles on the eyeball.…”

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An Analysis of Extraocular Muscle Forces in the Piked Dogfish (Squalus acanthias)

Gurley

Motta

2018

The Anatomical Record

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Vertebrates utilize six extraocular muscles that attach to a tough, protective sclera to rotate the eye. The goal of the study was to describe the maximum tetanic forces, as well as the torques produced by the six extraocular muscles of the piked dogfish Squalus acanthias to understand the forces exerted on the eye. The lateral rectus extraocular muscle of Squalus acanthias was determined to be parallel fibered with the muscle fibers bundled into discrete fascicles. The extraocular muscles attach to the sclera by muscular insertions. The total tensile forces generated by the extraocular muscles ranged from 1.18 N to 2.21 N. The torques of the extraocular muscles ranged from 0.39 N to 2.34 N. The torques were greatest in the principal direction of movement for each specific muscle. The lateral rectus produced the greatest total tensile force, as well as the greatest torque force component, while the medial rectus produced the second greatest. This is likely due to the constant rotational movement of the eye anteriorly and posteriorly to stabilize the visual image, as well as increase the effective visual field during swimming. Rotational forces in dimensions other than the primary direction of movement may contribute to motion in directions other than the principal direction during multi‐muscle contraction that occurs in the vertebrate eye. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. Anat Rec, 302:837–844, 2019. © 2018 Wiley Periodicals, Inc.

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Improvement of Targeted Gene Delivery to Human Cancer Cells by a Novel Trifunctional Crosslinker

Shiota

Shamsur

Kawahara

et al. 2009

Chemistry An Asian Journal

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A facile method for the construction of an immunoconjugate which displays targeting ligands, such as antibody fragments, with a high density is reported. For this purpose, we synthesized a novel trifunctional crosslinking reagent. By the use of this reagent, ligands targeting the specific cell can be displayed on the surface of the drug carrier with a high density. In this study, we display HER2 (human epidermal growth-factor receptor-2) binding ligands on branched polyethylenimine (PEI), which can form polyplexes with plasmid DNA. Kinetic analysis of the binding to the extracellular domain of HER2 show the PEI displaying a high density of ligands binds to the target more strongly compared to the PEI displaying ligands at a low density. The increased density of HER2 ligands displayed on the gene carrier contributes to the improved transfection efficiency. This approach can be applied to other drug delivery systems, including liposome, micelle, and so on.

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Motoneuronal innervation and mechanical properties of extraocular muscles in the catfish, (Ictalurus punctatus)

Cited by 8 publications

References 24 publications

Motoneurons of twitch and nontwitch extraocular muscle fibers in the abducens, trochlear, and oculomotor nuclei of monkeys

Motoneurons of twitch and nontwitch extraocular muscle fibers in the abducens, trochlear, and oculomotor nuclei of monkeys

An Analysis of Extraocular Muscle Forces in the Piked Dogfish (Squalus acanthias)

Improvement of Targeted Gene Delivery to Human Cancer Cells by a Novel Trifunctional Crosslinker

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