The Experts below are selected from a list of 54 Experts worldwide ranked by ideXlab platform
Stanley Monkhouse - One of the best experts on this subject based on the ideXlab platform.
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Cranial Nerves: Cranial Nerve motor pathways: upper and lower motor neurons
Cranial Nerves, 2005Co-Authors: Stanley MonkhouseAbstract:Upper and lower motor neurons Both somatic motor and branchiomotor Nerves supply voluntary muscles. Pathways between motor cortex and muscles may be thought of as being arranged in two neuronal groups: upper motor neurons and lower motor neurons. Axons of upper motor neurons decussate before synapsing with lower motor neurons, so the right motor cortex controls the left side of the body, and vice versa – contralateral control. Upper motor neurons: cortex to Nucleus For Cranial Nerves, cell bodies of upper motor neurons are in the head and neck area of the motor cortex. Axons descend, decussating just before synapsing with cell bodies of lower motor neurons which make up the motor Nucleus of that Cranial Nerve. The term upper motor neurons is also used clinically to include fibres from other brain centres (e.g. parietal lobe, basal ganglia, cerebellum, reticular formation, midbrain, etc.) that connect with the lower motor neurons in the Cranial Nerve Nucleus, thus influencing their activity. Lower motor neurons: Nucleus to muscle Cell bodies of lower motor neurons form the brain stem Nucleus. Axons leave the brain stem and pass in the Cranial Nerve to the destination. Thus, although most of the axon of the lower motor neuron is part of the peripheral nervous system, the cell body and first part of the axon is in the central nervous system. Corticonuclear and corticobulbar These terms describe the upper motor neuron pathways described above.
Darcy B. Kelley - One of the best experts on this subject based on the ideXlab platform.
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Androgen receptor mRNA expression in Xenopus laevis CNS: Sexual dimorphism and regulation in laryngeal motor Nucleus
Journal of Neurobiology, 1996Co-Authors: Julio Pérez, Michael A. Cohen, Darcy B. KelleyAbstract:Using Northern analysis, in situ hybridization, and nuclease protection assays, the expression and regulation of androgen receptor messenger RNA (AR mRNA) was examined in the CNS of juvenile Xenopus laevis. Only one of the AR mRNA isoforms expressed in X. laevis is transcribed in the CNS as shown by Northern blot analysis. Nuclease protection assays demonstrate that the expression of AR mRNA is higher in the brain stem than in the telencephalon and diencephalon. Although expression of AR mRNA is widespread throughout the CNS, cells of Cranial Nerve Nucleus IX-X (N. IX-X) and spinal cord display the highest in situ hybridization signals in their cytoplasm. Double labeling using horseradish peroxidase and digoxigenin labeled AR probes reveals that laryngeal and anterior spinal cord motor neurons express AR mRNA. More cells express AR mRNA in N. IX-X of males than of females. The number of AR expressing cells in N. IX-X decreases following gonadectomy in both sexes, and dihydrotestosterone (DHT) treatment for 1 month reverses this effect. Increased expression of AR mRNA in the brain of DHT treated animals is also apparent in nuclease protection assays. Sex differences in number of AR expressing cells and hormone regulation of AR mRNA expression in motor nuclei may influence neuromuscular systems devoted to sexually differentiated behaviors. © 1996 John Wiley & Sons, Inc.
Julio Pérez - One of the best experts on this subject based on the ideXlab platform.
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Androgen receptor mRNA expression in Xenopus laevis CNS: Sexual dimorphism and regulation in laryngeal motor Nucleus
Journal of Neurobiology, 1996Co-Authors: Julio Pérez, Michael A. Cohen, Darcy B. KelleyAbstract:Using Northern analysis, in situ hybridization, and nuclease protection assays, the expression and regulation of androgen receptor messenger RNA (AR mRNA) was examined in the CNS of juvenile Xenopus laevis. Only one of the AR mRNA isoforms expressed in X. laevis is transcribed in the CNS as shown by Northern blot analysis. Nuclease protection assays demonstrate that the expression of AR mRNA is higher in the brain stem than in the telencephalon and diencephalon. Although expression of AR mRNA is widespread throughout the CNS, cells of Cranial Nerve Nucleus IX-X (N. IX-X) and spinal cord display the highest in situ hybridization signals in their cytoplasm. Double labeling using horseradish peroxidase and digoxigenin labeled AR probes reveals that laryngeal and anterior spinal cord motor neurons express AR mRNA. More cells express AR mRNA in N. IX-X of males than of females. The number of AR expressing cells in N. IX-X decreases following gonadectomy in both sexes, and dihydrotestosterone (DHT) treatment for 1 month reverses this effect. Increased expression of AR mRNA in the brain of DHT treated animals is also apparent in nuclease protection assays. Sex differences in number of AR expressing cells and hormone regulation of AR mRNA expression in motor nuclei may influence neuromuscular systems devoted to sexually differentiated behaviors. © 1996 John Wiley & Sons, Inc.
Francesco Tomasello - One of the best experts on this subject based on the ideXlab platform.
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Dolichoectasia of the vertebrobasilar complex causing neural compression
Surgical Neurology International, 2014Co-Authors: Giovanni Grasso, Concetta Alafaci, Francesca Granata, Francesco TomaselloAbstract:Dear Editor, We have read with great interest the paper of Yuh et al.[4] reporting a case of symptomatic hydrocephalus due to vertebrobasilar dolichoectasia (VBD) compressing the brainstem. Ectatic or pathologically enlarged vertebrobasilar arteries have been reported with increasing frequency and associated with several clinical syndromes. These include an assortment of Cranial Nerve syndromes, transient or permanent motor deficit, cerebellar dysfunction, central sleep apnea, ischemic stroke, hypertension, and hydrocephalus as reported in the paper by Yuh et al.[4] Others and we have also described pyramidal tract signs and Cranial Nerve Nucleus dysfunction caused by vascular compression of the medulla oblongata by an elongated and ectatic vertebral artery and artery repositioning has proved to be an effective surgical treatment.[2,3] We agree with the authors that there is still uncertainty in the optimal treatment of VBD, since there has been no systematic review or long-term results from the different surgical interventions including microvascular decompression (MVD). However, to date, the MVD is the only interventional technique that is able to definitively treat such a pathological condition when associated with symptomatic neural compression. Neural compression by dolichoectatic vertebrobasilar arteries is an insidious clinical entity presenting several challenges to the neurosurgeon, because the operative procedure not only must be effective in relieving the symptoms, but also must preserve functioning neural and vascular structures. Therefore, the proper management should begin from the first observation of the patient affected by such an abnormality. A careful neurological examination is imperative to ensure that the patient's symptoms are attributable to vascular compression. Neuroradiological investigations are mandatory for diagnosis and surgical planning. With the advent of the magnetic resonance imaging technique, which, using specific three-dimensional sequences, has offered a good visualization of both Cranial Nerves and cerebral vessels, neurovascular compression disorders have been diagnosed with increasing frequency. In the clinical decision-making process, the neurosurgeon must determine whether the patient's symptoms are significant enough to warrant the surgical intervention. Finally, vessel repositioning must be performed carefully because of the elevated risk of injuring Cranial Nerves and the small perforating vessels of the vertebrobasilar system.[1] According to the literature and based on our experience, such a strategy can offer a complete clinical accomplishment with a functional respect of the neural structures.
Maria Elisa Paiva Pires - One of the best experts on this subject based on the ideXlab platform.
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METASTASIS TO THE UNILATERAL OCULOMOTOR Nucleus COMPLEX Case report
Arquivos De Neuro-psiquiatria, 2006Co-Authors: Péricles Maranhão-filho, Maria Elisa Paiva PiresAbstract:This article describes a 76 years old man that, after lung cancer surgery, showed left extrinsic oculomotor paralysis and contralateral paralysis of the superior rectus muscle associated with bilateral ptosis. Magnetic resonance imaging confirmed a rare situation characterized by an isolated metastasis in the region of the left third Cranial Nerve Nucleus, probably compromising the superior rectus subNucleus and the central caudal Nucleus, therefore justifying the bilateral oculomotor involvement.