Os macacos Cebus apella são hábeis com suas mãos e capazes de utilizar ferrementas (paus e pedras) para resolver problemas, podendo ser treinados como assistentes de pessoas quadriplégicas. São escassas ainda as informações em neuroanatomia desses primatas, o que motiva a presente pesquisa, cujo propósito é o de enfocar a morfologia externa e interna do tronco encefálico. Foram estudados 20 espécimes do macaco Cebus apella que já estavam fixados com formol a 10%, pertencentes ao acervo de pesquisa do laboratório de Anatomia da Universidade Federal de Uberlândia. Após isolamento do encéfalo e remoção das meninges procedeu ? se ao estudo da superfície externa em 14 peças. A dissecção por técnica usual preservou características morfológicas da superfície e origem aparente de nervos cranianos, que foram identificados. Em análise macroscópica, o tronco encefálico mostra ? se bem desenvolvido destacando ? se ainda em sua face lateral a origem aparente do nervo trigêmeo e os pedúnculos cerebelares médios, bem evidentes. Na face dorsal, em relação ao IV ventrículo identificam ? se os véus medulares superior e inferior, bem como o sulco mediano e a eminência medial. Os pedúnculos cerebelares superior e inferior também são bem destacados. Na medula oblonga são identificados, entre outros, os relevos correspondentes às olivas e às pirâmides, além da fissura mediana anterior e a região da decussação das pirâmides, Nem sempre são nítidos o sulco bulbo ? pontino e o forame cego. Os fascículos grácil e cuneiforme são bastante desenvolvidos bem como os tubérculos correspondentes. Para os estudos das estruturas internas do tronco encefálico, 6 peças, já fixadas, foram congeladas com nitrogênio líquido e cortadas no criostato entre ?27º C e ? 30º C, seguindo ? se a feitura de cortes transversais, em seis níveis (colículos superior e inferior, origem aparente do nervo trigêmeo, porções superior, média e inferior da oliva, e decussação das pirâmides), com espessura de 60 µc, corados segundo o método de Mulligan. As estruturas evidenciáveis são descritas com detalhes comparando ? se os dados obtidos com os da literatura consultada. Os termos anatômicos foram referidos segundo a Terminologia Anatômica Internacional, 1ª edição brasileira ? 2001, Ed. Manole Ltda. / The Cebus apella monkey are able to use their nands and to use tools like woods and stones to solve problems. They can be trained to act as quadriplégicas people?s assistants. The Neuroanatomy information about these primates are little, that?s the reason for this research and its purpose is to accomplish a macroscophial anatomic study of encephalic trunk external and internal surface structure. It was studied Cebus apella monkeu 20 especimens that was already fixed on 10% formaldehyde. These monkeys are from research?s heap of Universidade Federal de Uberlândia. The monkey encephalon were removed using an osteótomo. After removing the meninges, theirs external surface study was started on 14 of them. The dissection using usual technique could preserve the morphological characteristics of the surface and cranial nerve apparent origim, that could be identified too. Under a macroscophical analysis, the encephalic trun looks very elaborated and the trigemini nerve and pedunculus cerebellaris aparent origin, very evident, was stood out in its lateral face. In the dorsal face, in relation to fourth ventricle, the inferior and superior velum medullare could be identified as well as the sulcus medianus and the eminentia medialis. The superior pedunculus cerebellaris, as well as the inferior ones, were very stood out too. On the medulla oblongata were identified, beyond others, the relieves corresponding to the oliva and the decussatio pyramidum region. The sulcus bulbus ? pons and the foramen caecum not always are bright. The fasciculus gracilis, as well as the cuneatus ones, are very elaborated as well as the corresponding tuberculuns.The brain stem internal structure study 6 already fixed pieces were froze with liquid nitrong and cut in criostato, under the temperature between ?27ºC and ? 30º C. After this, transversal cuts were made on 6 levels (superior and inferior nerve trigemini aparent origin, olivas superior, medium and inferior portion and decussatio pyramidum), with the thickness of 60µc, roddy according to the Mulligan method. The evidentiable structures are described in details comparing data obtained from the consulted literature. The anatomic terms were aforesaid according to Terminologia Anatômica Internacional, 1ª edição brasileira ? 2001, Ed. Manole Ltda.

O nervo vestíbulo-coclear da cobaia possui peculiaridades não encontradas em outros nervos periféricos. Não foram encontradas informações detalhadas sobre os aspectos morfométricos do VIII nervo craniano em cobaias adultas na literatura. A avaliação descritiva e quantitativa no presente estudo, evidencia informações que precedem o estudo das alterações que ocorrem em modelos experimentais de neuropatias do VIII nervo craniano e as doenças ou lesões que possam afetar o homem. Foram utilizadas 8 cobaias adultas, perfundidas com glutaraldeído a 2,5% em tampão cacodilato de sódio (0,025 M). Seus nervos direito e esquerdo (n=6, 4 nervos direito e 2 esquerdos) foram dissecados na região mediana do nervo e pós fixado com tetróxido de ósmio (OsO4) a 1% e incluídos em resina epóxi Poly/Bed 812®. Os fragmentos foram cortados em secções transversais semifinas seriadas (6 nervos) com uma espessura de 0,5 μm e corados com azul de toluidina para a microscopia de luz. Foram analisados os aspectos histológicos descritivos e topográficos do nervo vestíbulo-coclear em cobaias adultas, bem como os aspectos histométricos na parte mediana do nervo, no referente a densidade de fibras mielínicas, a distribuição dos diâmetros de tal tipo de fibras mielínicas, ao cálculo da razão G e o número de vasos sangüíneos encontrados dentro da área de cada nervo. O nervo coclear é envolvido pelo vestibular na porção inicial da junção de ambos. O conjunto, nervos coclear e vestibular e nervo vestíbulo-coclear têm a aparência bifurcada da letra Y, na horizontal com os ramos lateralizados, possuindo em média 5 mm de comprimento. É ricamente vascularizado e documenta uma completa interposição das fibras dos nervos coclear e vestibular, quando o fascículo do VIII nervo está completamente constituído. As suas fibras mielínicas dispõem-se paralelamente em seu sentido longitudinal e são circundadas por escasso tecido endoneural. Não foram evidencias fibras amielínicas no VIII nervo. A distribuição das fibras mielínicas no segmento mediano do VIII nervo craniano foi unimodal, havendo predomínio de fibras com 3,5 m de diâmetro. O número de fibras foi de 5.390 ± 1.504 fibras. O diâmetro das fibras variou de 1,5 a 6 m de diâmetro. Os axônios com 2,5 m de diâmetro foram predominantes quantitativamente: 6.757 ± 1.922 axônios. O diâmetro axonal variou entre 1 a 4,5 m. A densidade média das fibras do VIII nervo em seu segmento mediano foi de 41.474 ± 4384 fibras/mm2. O diâmetro fascicular foi de 0,77 ± 0,04 mm. A razão G varia de 0,2 a 0,9. O maior número de fibras tem razão G de 0,7 e 0,6, respectivamente, predominando as fibras com 0,7. Os resultados descritos neste trabalho científico são originais, contendo alguns resultados inéditos e pouco estudados na literatura científica sobre a anatomia e morfometria do VIII nervo craniano em cobaia. O nervo vestíbulo-coclear da cobaia é um nervo sensitivo aferente especial, e bem diferente em sua anátomo-fisiologia de todos os outros nervos sensitivos e motores encontrados nos mamíferos. A cobaia adulta é um excelente modelo experimental para o estudo do nervo vestíbulo-coclear, semelhantes aos de humanos. / The vestibulocochlear (VIIIth cranial nerve) nerve of guinea pigs have special features not common for peripheral nerves in general. There are no detailed reports on the morphometric characteristics of the VIII nerve in adult guinea pigs. This is a descriptive and qualitative study that shows normal parameters that are useful in experimental models of the VIIIth nerve neuropathy. Eight adult guinea pigs were perfused with 2.5% glutaraldehyde in isotonic cacodilate buffer (0.025M). The right (N=4) and left (N=2) nerves were dissected in the median region, post-fixed in 1% osmuin tetroxide and embedded in epoxy resin. Semithin (0.5 µm) serial transverse sections were stained with 1% toluidine blue for light microscopy study. The descriptive histology and the topographical and histometric aspects of the median region of the nerve were analyzed, including myelinated fiber density, myelinated fiber diameter distribution, g ratio and number of endoneural capillary vessels. The cochlear nerve is enveloped by the vestibular nerve when they join together. Both, the cochlear and the vestibular nerves join to form the vestibulocochlear nerve with a Y shape, with approximately 5 mm in length. The nerve is widely vascularized and presents a complete mixture of the vestibular and cochlear myelinated fibers when the VIII nerve fascicle is constituted. The myelinated fibers are longitudinally oriented and present few endoneural connective tissue in between. No unmyelinated fibers were evidenced in the VIII nerve. The myelinated fiber diameter distribution was unimodal, with a peak at 3.5, and intervals between 1,5 and 6 m. The average number of fibers was 5.390 ± 1.504. The myelinated axon diameter distribution was also unimodal, with a peak at 2.5 µm of diameter were predominant quantitatively: 6.757 ± 1.922, and intervals between 1 and 4.5 µm. The average myelinated fiber density was 41.474 ± 4384 mm2, spread in a fascicular diameter of 0.77 ± 0.04 mm. The g ratio values varied from 0.2 to 0.9 and most of the myelinated fibers showed g ratio values of 0.7. Our results are original and only few parameters studied here were described in the literature. The vestibulocochlear nerve of the guinea pigs is a special afferent nerve, differing from other peripheral nerves (sensitive and motor) in its main anatomic and physiological characteristics, compared to other nerves from mammals. The adult guinea pig is an excellent model for the vestibulocochlear nerve neuropathy studies once it is similar to the human nerve.

Deux des trois divisions du système nerveux viscéral – le système nerveuxparasympathique et le système nerveux entérique – sont associés aux nerfscrâniens (le troisième, le système nerveux sympathique, est associé aux nerfsspinaux). Cette étude est centrée sur les nerfs crâniens et sur les ganglionsqui leur sont associés ; plus précisément sur les stratégies cellulaires ayantlieu lors de leur ontogenèse.Je propose des principes unificateurs concernant les interactions neuronalesmises en jeu lors de la formation des nerfs crâniens branchiomériques ainsiqu’un nouveau mode de migration des précurseurs des ganglionsparasympathiques couplé à la migration de leurs partenairespréganglionnaires jusqu’au site de formation du ganglion. Enfin, je présentecertaines observations préliminaires suggérant que les précurseurs dusystème nerveux entériques utilisent ce même modus operandi pour envahirl’oesophage. / Two of the three divisions of the visceral nervous system —theparasympathetic and the enteric nervous systems— are associated withcranial nerves (the third one, the sympathetic division, being associatedwith spinal nerves). This work is focused on cranial nerves and associatedganglia and more particularly on the cellular strategies presiding over theirontogeny and wiring.I propose unifying principles of neuronal interactions that govern theformation of branchiomeric cranial nerves, as well as a novel migrationpathway followed by parasympathetic precursors, which use theirpreganglionic nerves to migrate to the site of ganglion formation. Finally, Ipresent preliminary observations suggesting that the enteric neuronalprecursors use the same trick to populate the esophagus.

O nervo vestíbulo-coclear da cobaia possui peculiaridades não encontradas em outros nervos periféricos. Não foram encontradas informações detalhadas sobre os aspectos morfométricos do VIII nervo craniano em cobaias adultas na literatura. A avaliação descritiva e quantitativa no presente estudo, evidencia informações que precedem o estudo das alterações que ocorrem em modelos experimentais de neuropatias do VIII nervo craniano e as doenças ou lesões que possam afetar o homem. Foram utilizadas 8 cobaias adultas, perfundidas com glutaraldeído a 2,5% em tampão cacodilato de sódio (0,025 M). Seus nervos direito e esquerdo (n=6, 4 nervos direito e 2 esquerdos) foram dissecados na região mediana do nervo e pós fixado com tetróxido de ósmio (OsO4) a 1% e incluídos em resina epóxi Poly/Bed 812®. Os fragmentos foram cortados em secções transversais semifinas seriadas (6 nervos) com uma espessura de 0,5 μm e corados com azul de toluidina para a microscopia de luz. Foram analisados os aspectos histológicos descritivos e topográficos do nervo vestíbulo-coclear em cobaias adultas, bem como os aspectos histométricos na parte mediana do nervo, no referente a densidade de fibras mielínicas, a distribuição dos diâmetros de tal tipo de fibras mielínicas, ao cálculo da razão G e o número de vasos sangüíneos encontrados dentro da área de cada nervo. O nervo coclear é envolvido pelo vestibular na porção inicial da junção de ambos. O conjunto, nervos coclear e vestibular e nervo vestíbulo-coclear têm a aparência bifurcada da letra Y, na horizontal com os ramos lateralizados, possuindo em média 5 mm de comprimento. É ricamente vascularizado e documenta uma completa interposição das fibras dos nervos coclear e vestibular, quando o fascículo do VIII nervo está completamente constituído. As suas fibras mielínicas dispõem-se paralelamente em seu sentido longitudinal e são circundadas por escasso tecido endoneural. Não foram evidencias fibras amielínicas no VIII nervo. A distribuição das fibras mielínicas no segmento mediano do VIII nervo craniano foi unimodal, havendo predomínio de fibras com 3,5 m de diâmetro. O número de fibras foi de 5.390 ± 1.504 fibras. O diâmetro das fibras variou de 1,5 a 6 m de diâmetro. Os axônios com 2,5 m de diâmetro foram predominantes quantitativamente: 6.757 ± 1.922 axônios. O diâmetro axonal variou entre 1 a 4,5 m. A densidade média das fibras do VIII nervo em seu segmento mediano foi de 41.474 ± 4384 fibras/mm2. O diâmetro fascicular foi de 0,77 ± 0,04 mm. A razão G varia de 0,2 a 0,9. O maior número de fibras tem razão G de 0,7 e 0,6, respectivamente, predominando as fibras com 0,7. Os resultados descritos neste trabalho científico são originais, contendo alguns resultados inéditos e pouco estudados na literatura científica sobre a anatomia e morfometria do VIII nervo craniano em cobaia. O nervo vestíbulo-coclear da cobaia é um nervo sensitivo aferente especial, e bem diferente em sua anátomo-fisiologia de todos os outros nervos sensitivos e motores encontrados nos mamíferos. A cobaia adulta é um excelente modelo experimental para o estudo do nervo vestíbulo-coclear, semelhantes aos de humanos. / The vestibulocochlear (VIIIth cranial nerve) nerve of guinea pigs have special features not common for peripheral nerves in general. There are no detailed reports on the morphometric characteristics of the VIII nerve in adult guinea pigs. This is a descriptive and qualitative study that shows normal parameters that are useful in experimental models of the VIIIth nerve neuropathy. Eight adult guinea pigs were perfused with 2.5% glutaraldehyde in isotonic cacodilate buffer (0.025M). The right (N=4) and left (N=2) nerves were dissected in the median region, post-fixed in 1% osmuin tetroxide and embedded in epoxy resin. Semithin (0.5 µm) serial transverse sections were stained with 1% toluidine blue for light microscopy study. The descriptive histology and the topographical and histometric aspects of the median region of the nerve were analyzed, including myelinated fiber density, myelinated fiber diameter distribution, g ratio and number of endoneural capillary vessels. The cochlear nerve is enveloped by the vestibular nerve when they join together. Both, the cochlear and the vestibular nerves join to form the vestibulocochlear nerve with a Y shape, with approximately 5 mm in length. The nerve is widely vascularized and presents a complete mixture of the vestibular and cochlear myelinated fibers when the VIII nerve fascicle is constituted. The myelinated fibers are longitudinally oriented and present few endoneural connective tissue in between. No unmyelinated fibers were evidenced in the VIII nerve. The myelinated fiber diameter distribution was unimodal, with a peak at 3.5, and intervals between 1,5 and 6 m. The average number of fibers was 5.390 ± 1.504. The myelinated axon diameter distribution was also unimodal, with a peak at 2.5 µm of diameter were predominant quantitatively: 6.757 ± 1.922, and intervals between 1 and 4.5 µm. The average myelinated fiber density was 41.474 ± 4384 mm2, spread in a fascicular diameter of 0.77 ± 0.04 mm. The g ratio values varied from 0.2 to 0.9 and most of the myelinated fibers showed g ratio values of 0.7. Our results are original and only few parameters studied here were described in the literature. The vestibulocochlear nerve of the guinea pigs is a special afferent nerve, differing from other peripheral nerves (sensitive and motor) in its main anatomic and physiological characteristics, compared to other nerves from mammals. The adult guinea pig is an excellent model for the vestibulocochlear nerve neuropathy studies once it is similar to the human nerve.

Background: Vagus nerve stimulation is increasingly applied to treat epilepsy, psychiatric conditions and potentially chronic heart failure. After implanting vagus nerve electrodes to the cervical vagus nerve, side effects such as voice alterations and dyspnea or missing therapeutic effects are observed at different frequencies. Cervical vagus nerve branching might partly be responsible for these effects. However, vagus nerve branching has not yet been described in the context of vagus nerve stimulation. Materials and methods: Branching of the cervical vagus nerve was investigated macroscopically in 35 body donors (66 cervical sides) in the carotid sheath. After X-ray imaging for determining the vertebral levels of cervical vagus nerve branching, samples were removed to confirm histologically the nerve and to calculate cervical vagus nerve diameters and cross-sections. Results: Cervical vagus nerve branching was observed in 29%of all cases (26% unilaterally, 3% bilaterally) and proven histologically in all cases. Right-sided branching (22%) was more common than left-sided branching (12%) and occurred on the level of the fourth and fifth vertebra on the left and on the level of the second to fifth vertebra on the right side. Vagus nerves without branching were significantly larger than vagus nerves with branches, concerning their diameters (4.79mm vs. 3.78mm) and cross-sections (7.24 mm2 vs. 5.28mm2). Discussion: Cervical vagus nerve branching is considerably more frequent than described previously. The side-dependent differences of vagus nerve branching may be linked to the asymmetric effects of the vagus nerve. Cervical vagus nerve branching should be taken into account when identifying main trunk of the vagus nerve for implanting electrodes to minimize potential side effects or lacking therapeutic benefits of vagus nerve stimulation.

Ein bezüglich Datenakquisition und Nachverarbeitung optimiertes Visualisie-rungsprotokoll zur dreidimensionalen Darstellung der Hirnnerven V-VIII im Be-reich der basalen Zisternen wird vorgestellt. Auf der Basis von hochauflösen-den MRT Daten und unter Verwendung der Volume-Rendering-Technik entstanden insgesamt 10 Standardansichten der genannten Hirnnerven, die deren vollständige und zeiteffektive intrazisternale Abbildung mit besonderer Beachtung pathophysiologisch relevanter Zonen ermöglichen. Das Protokoll zeigte in der Evaluation an Patienten mit neurovaskulären Konflikten und an-deren neuralen Kompressionssyndromen im Bereich des Kleinhirnbrücken-winkels seine Eignung bezüglich Bildqualität und diagnostischer Wertigkeit. Probleme traten vor allem aufgrund von Pulsations- und Bewegungsartefakten im akquirierten MRT-Datensatz, sowie zu enger Zisternen auf der Höhe der virtuellen Kameraposition auf. Diese ließen sich in den meisten Fällen jedoch durch leichte Parametervariationen beheben. Zur genauen Identifikation der Gefäße und zur Vermeidung der Weitergabe von Fehlzuordnungen war zu-sätzlich zu den Rekonstruktionen die Betrachtung des Originaldatensatzes er-forderlich. Die Nachverfolgung der mit dem beschriebenen Protokoll virtuell zisternoskopisch untersuchten Patienten ergab bei der weit überwiegenden Zahl der verfolgbaren Patienten Konsequenzen hinsichtlich Diagnose und/oder Therapie. Die Korrelation mit intraoperativen Befunden konnte nur bei zwei Patienten mit Akustikusneurinomen erfolgen, wobei hier eine Über-einstimmung festgestellt werden konnte. Ursache für die nur geringe Zahl der zur Verfügung stehenden intraoperativen Befunde ist die lange Latenz zwi-schen Bildgebung und neurochirurgischer Intervention bei neurovaskulären Konflikten. Zusammenfassend lässt sich feststellen dass die virtuelle Zister-noskopie nach dem vorgestellten Protokoll eine komplementäre Bildgebungs-technik ist, die wichtige räumliche Informationen zu neurovaskulären Interakti-onen in den basalen Zisternen liefert. Weitere Untersuchungen, insbesondere die intraoperative Befundkorrelation, sind jedoch erforderlich. / The following thesis presents a protocol for the three-dimensional visualization of the cranial nerves V-VIII within the basal cisterns, being optimized with regard to data acquisition and postprocessing. Based on high resolution MRI datasets and using the volume rendering technique, 10 standardized views of the aforementioned cranial nerves were developed. Thus, the complete and time effective intracisternal depiction was intended to be made possible, focussing on pathophysiological important areas of the nerves. The protocol showed its suitability concerning image quality and diagnostic value in evaluation of patients with neurovascular conflicts or other neural compression syndromes in the cerebello-pontine angle. Problems mainly occurred as a result of pulsation and motion artefacts in the MR dataset and narrow cisterns in the level of the virtual camera position. In most cases they could be solved by slight variations of the postprocessing parameters. To guaranty the correct identification of the vessels and to avoid the risk of giving incorrectly assigned anatomic information to subsequent readers, the additional inspection of original dataset is necessary. In the follow up of the examined patients consequences in diagnosis and/or therapy were found in the most cases. The correlation of the virtual cisternoscopic images with the intraoperative results could only be performed in two patients with acoustic neuromas and was successful. The reason for the small amount of available intraoperative results is the latency between imaging and neurosurgical intervention in neurovascular conflicts. Concluding the virtual cisternoscopy following the introduced protocol is a complementary imaging technique that provides important spatial information about neurovascular interactions within the basal cisterns. Yet further investigations, especially the intraoperative correlation of the results, are necessary.

No description available.