Anatomic and physiological characteristics of the ferret lateral rectus muscle and abducens nucleus

Bishop, Keith; McClung, J. Ross; Goldberg, Stephen J.; Shall, Mary S.

doi:10.1152/japplphysiol.00580.2007

Cited by 7 publications

(3 citation statements)

References 54 publications

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“…However, we think this is unlikely as the ferret eye contains a prominent visual streak and a much lower variation in retinal ganglion cell density across the retina (Stone, 1965;Henderson, 1985), raising the possibility that this species relies less on eye movements than other carnivores. Indeed, the lateral rectus muscle, which is responsible for abduction of the eye, has a much slower twitch contraction time and is innervated by relatively few abducens nucleus motoneurons compared to cats (Bishop et al, 1985). Moreover, the approach-to-target responses showed a comparable dependence on stimulus location and duration and were also consistently more accurate for auditory than for visual stimuli, indicating that head movements alone provide an appropriate measure of localization performance.…”

Section: Discussionmentioning

confidence: 99%

Behavioural benefits of multisensory processing in ferrets

Hammond-Kenny

Bajo

King

et al. 2016

Eur J of Neuroscience

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Enhanced detection and discrimination, along with faster reaction times, are the most typical behavioural manifestations of the brain's capacity to integrate multisensory signals arising from the same object. In this study, we examined whether multisensory behavioural gains are observable across different components of the localization response that are potentially under the command of distinct brain regions. We measured the ability of ferrets to localize unisensory (auditory or visual) and spatiotemporally coincident auditory-visual stimuli of different durations that were presented from one of seven locations spanning the frontal hemifield. During the localization task, we recorded the head movements made following stimulus presentation, as a metric for assessing the initial orienting response of the ferrets, as well as the subsequent choice of which target location to approach to receive a reward. Head-orienting responses to auditory-visual stimuli were more accurate and faster than those made to visual but not auditory targets, suggesting that these movements were guided principally by sound alone. In contrast, approach-to-target localization responses were more accurate and faster to spatially congruent auditory-visual stimuli throughout the frontal hemifield than to either visual or auditory stimuli alone. Race model inequality analysis of head-orienting reaction times and approach-totarget response times indicates that different processes, probability summation and neural integration, respectively, are likely to be responsible for the effects of multisensory stimulation on these two measures of localization behaviour.

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Section: Discussionmentioning

confidence: 99%

Behavioural benefits of multisensory processing in ferrets

Hammond-Kenny

Bajo

King

et al. 2016

Eur J of Neuroscience

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“…This could provide valuable clues in the pathophysiology of EOM involvement and in disease pathophysiology in general, since the EOM differ anatomically and physiologically from skeletal muscles. They have distinct fibre type composition, 99 multiple innervation, 100 smaller motor units, 101 higher levels of utrophin expression, 102 a distinct contraction–excitation coupling, 103 have an increased capability of regeneration and preferentially use glucose‐based aerobic metabolic pathways. 69 The latter means that EOM are packed with mitochondria, explaining the predominant ocular phenotype in mitochondrial diseases such as CPEO.…”

Section: Discussionmentioning

confidence: 99%

Clinical and imaging clues to the diagnosis and follow‐up of ptosis and ophthalmoparesis

Keene

Kan

Meeren

et al. 2022

J cachexia sarcopenia muscle

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Ophthalmoparesis and ptosis can be caused by a wide range of rare or more prevalent diseases, several of which can be successfully treated. In this review, we provide clues to aid in the diagnosis of these diseases, based on the clinical symptoms, the involvement pattern and imaging features of extra‐ocular muscles (EOM). Dysfunction of EOM including the levator palpebrae can be due to muscle weakness, anatomical restrictions or pathology affecting the innervation. A comprehensive literature review was performed to find clinical and imaging clues for the diagnosis and follow‐up of ptosis and ophthalmoparesis. We used five patterns as a framework for differential diagnostic reasoning and for pattern recognition in symptomatology, EOM involvement and imaging results of individual patients. The five patterns were characterized by the presence of combination of ptosis, ophthalmoparesis, diplopia, pain, proptosis, nystagmus, extra‐orbital symptoms, symmetry or fluctuations in symptoms. Each pattern was linked to anatomical locations and either hereditary or acquired diseases. Hereditary muscle diseases often lead to ophthalmoparesis without diplopia as a predominant feature, while in acquired eye muscle diseases ophthalmoparesis is often asymmetrical and can be accompanied by proptosis and pain. Fluctuation is a hallmark of an acquired synaptic disease like myasthenia gravis. Nystagmus is indicative of a central nervous system lesion. Second, specific EOM involvement patterns can also provide valuable diagnostic clues. In hereditary muscle diseases like chronic progressive external ophthalmoplegia (CPEO) and oculo‐pharyngeal muscular dystrophy (OPMD) the superior rectus is often involved. In neuropathic disease, the pattern of involvement of the EOM can be linked to specific cranial nerves. In myasthenia gravis this pattern is variable within patients over time. Lastly, orbital imaging can aid in the diagnosis. Fat replacement of the EOM is commonly observed in hereditary myopathic diseases, such as CPEO. In contrast, inflammation and volume increases are often observed in acquired muscle diseases such as Graves' orbitopathy. In diseases with ophthalmoparesis and ptosis specific patterns of clinical symptoms, the EOM involvement pattern and orbital imaging provide valuable information for diagnosis and could prove valuable in the follow‐up of disease progression and the understanding of disease pathophysiology.

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“…Neostigmine, an alternative to edrophonium for pharmacological testing, is a long-acting AChE, making it more suited in the examination of ocular motility and diplopia testing [1]. EOMs [24]. When lateral rectus was affected in patients with OMG, esotropia was found and patients would complained a horizontal double vision, which was aggravated when gazed laterally.…”

Section: Discussionmentioning

confidence: 99%

Clinical Features Of Ocular Myasthenia Gravis In Adult Patients: Diplopia and Ophthalmoplegia

Tang¹,

Chen²,

Liu³

et al. 2020

Preprint

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Background: The diagnosis of ocular myasthenia gravis (OMG) in adult patients remained challenged and the characteristics of diplopia and ophthalmoplegia in OMG is unclear. Methods: Retrospective case series study of medical records of 40 adult patients diagnosed with OMG at The First Affiliated Hospital of Jinan University from June, 2016 to December, 2019, was performed to analyze the clinical features, diagnostic tests and preferential affected extraocular muscles of OMG. Results: 40 adult patients with OMG were involved and men represented 20 (50%) of cases. Mean age (±SD) among men was 49 ± 21 years (range: 19-81 years) and 40 ± 15 years (range: 21-65 years) among women. 18 patients (45.0%) were 18 to 39 years old, 12 patients (30.0%) were 40 to 59 years old, 9 patients (22.5%) were 60 to 79 years old, 1 patients (2.5%) over 80 years old. The median course of the disease among all the patients was 6 months (ranged: 1 month to 10 years). Neostigmine test was positive in 32 of 40 patients (80.0%), acetycholine receptors antibodies assay was positive in 4 of 40 patients (10.0%), Thymus CT showed abnormal findings in 5 of 40 patients (12.5%). At the first visit, 27 patients (67.5%) showed diplopia only, 9 patients (22.5%) showed ptosis only, 4 patients (10.0%) showed diplopia with ptosis. The most paralytic EOM, determined through light reflection, cover-uncover test and red glass test for patients presented with diplopia only (n=27) and diplopia with ptosis (n=9), was lateral rectus (51.6%), superior rectus (19.4%), medial rectus (12.9%), inferior rectus (9.8%), superior oblique (3.2%), inferior oblique (3.2%) in order. Conclusions: OMG mainly affected adults at the working ages. Diplopia serves as initial symptom in most adult patients with OMG and lateral rectus is most susceptible.

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Anatomic and physiological characteristics of the ferret lateral rectus muscle and abducens nucleus

Cited by 7 publications

References 54 publications

Behavioural benefits of multisensory processing in ferrets

Behavioural benefits of multisensory processing in ferrets

Clinical and imaging clues to the diagnosis and follow‐up of ptosis and ophthalmoparesis

Clinical Features Of Ocular Myasthenia Gravis In Adult Patients: Diplopia and Ophthalmoplegia

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