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Acta Neurochirurgica Mar 2016Posttraumatic pontomedullary rents have been described mainly as postmortem histopathological findings in patients who died immediately or within the first hours after...
Posttraumatic pontomedullary rents have been described mainly as postmortem histopathological findings in patients who died immediately or within the first hours after trauma. To the best of our knowledge, no long-term survivors of this condition have been described, and those surviving initially were always severely impaired. We present the first patient with this condition and with corresponding lesions on imaging who survived longer than 3 months. Moreover, the patient regained almost complete independence 1 year after the trauma. We briefly discuss the proposed mechanisms of this injury. We conclude that this lesion, when incomplete, is not always lethal and can exceptionally have a good clinical outcome. Prevention of respiratory failure is of utmost importance in these patients.
Topics: Adult; Brain Injuries; Humans; Male; Medulla Oblongata; Pons
PubMed: 26801511
DOI: 10.1007/s00701-016-2712-9 -
Respiratory Physiology & Neurobiology Aug 2009Mammalian central pattern generators producing rhythmic movements exhibit robust but flexible behavior. However, brainstem network architectures that enable these...
Mammalian central pattern generators producing rhythmic movements exhibit robust but flexible behavior. However, brainstem network architectures that enable these features are not well understood. Using precise sequential transections through the pons to medulla, it was observed that there was compartmentalization of distinct rhythmogenic mechanisms in the ponto-medullary respiratory network, which has rostro-caudal organization. The eupneic 3-phase respiratory pattern was transformed to a 2-phase and then to a 1-phase pattern as the network was physically reduced. The pons, the retrotrapezoid nucleus and glycine mediated inhibition are all essential for expression of the 3-phase rhythm. The 2-phase rhythm depends on inhibitory interactions (reciprocal) between Bötzinger and pre-Bötzinger complexes, whereas the 1-phase-pattern is generated within the pre-Bötzinger complex and is reliant on the persistent sodium current. In conditions of forced expiration, the RTN region was found to be essential for the expression of abdominal late expiratory activity. However, it is unknown whether the RTN generates or simply relays this activity. Entrained with the central respiratory network is the sympathetic nervous system, which exhibits patterns of discharge coupled with the respiratory cycle (in terms of both gain and phase of coupling) and dysfunctions in this coupling appear to underpin pathological conditions. In conclusion, the respiratory network has rhythmogenic capabilities at multiple levels of network organization, allowing expression of motor patterns specific for various physiological and pathophysiological respiratory behaviors.
Topics: Animals; Humans; Models, Biological; Neural Pathways; Periodicity; Pons; Respiration; Respiratory Center
PubMed: 19540366
DOI: 10.1016/j.resp.2009.06.011 -
Journal of Neurophysiology Oct 1983Extracellular microelectrode recordings were made from single neurons in the pontomesencephalic brain stem of head-restrained but nonanesthetized cats whose behavioral...
Extracellular microelectrode recordings were made from single neurons in the pontomesencephalic brain stem of head-restrained but nonanesthetized cats whose behavioral state was continuously monitored polygraphically. A population of neurons was encountered with the unusual property of progressively decreasing discharge rate as the cats passed from waking (W) through synchronized sleep (S) to desynchronized sleep (D). In many cases there was a complete cessation of firing in desynchronized sleep, suggesting the designation D-off cell for this neuronal subtype. The D-off cell population was distributed in a bandlike zone across the brain stem at the pontomesencephalic junction with dense concentration of cells in aminergic nuclei: the serotonergic dorsal raphe and raphe linearis centralis and noradrenergic locus ceruleus and peribrachial regions. Aside from a sparse distribution in the central tegmental field, there were no D-off cells in pontine reticular nuclei where cells of the D-on type abound. The proportion of cells showing the D-off property and the magnitude of the state-related change were correlated across nuclear groups as follows: raphe and peribrachial (highest), locus ceruleus (intermediate), and reticular (lowest) for both values. The firing rates of D-off cells tended to be low in waking with very regular interspike intervals. This characteristic firing pattern and the anatomical distribution suggests that D-off cells may be tentatively identified as aminergic. The marked contrasts in aminergic neuronal activity between waking and desynchronized sleep are interpreted as possibly playing a role in state generation through progressive distribution of cholinergic neurons postsynaptic to the D-off cell population. Predictable results would not only be a change in the excitability of the postsynaptic population but also a change in response mode related to a shift in neurotransmitter throughout the brain.
Topics: Action Potentials; Animals; Cats; Locus Coeruleus; Male; Neurons; Pons; Raphe Nuclei; Reticular Formation; Sleep
PubMed: 6631462
DOI: 10.1152/jn.1983.50.4.770 -
Reviews in the Neurosciences 1995In rodents, third order gustatory neurons reside in the parabrachial nuclei of the dorsal pons. Lesions in this area of the brain have a variety of consequences on... (Review)
Review
In rodents, third order gustatory neurons reside in the parabrachial nuclei of the dorsal pons. Lesions in this area of the brain have a variety of consequences on taste-related behaviors. Some behaviors are severely impaired, such as the expression of either conditioned taste aversion or depletion-induced sodium appetite. Other taste-based behaviors are less affected or not influenced at all. Although the lesion-behavior approach possesses serious methodological limitations, the constellation of findings from studies employing this experimental strategy in the PBN has promising implications. Foremost among these is the suggestion that the neural circuitry subserving performance in some of these taste-guided behavioral paradigms is dissociable. This paper critically reviews this body of behavioral research and discusses the conceptual ramifications of the results.
Topics: Animals; Behavior, Animal; Electrophysiology; Neural Pathways; Pons; Rats; Taste
PubMed: 8564025
DOI: 10.1515/revneuro.1995.6.2.143 -
Acta Neurochirurgica. Supplementum 198319 cases of partial or complete ponto-medullary avulsion are reported. This type of damage seems to be produced by severe hyperextension of the head on the neck with or...
19 cases of partial or complete ponto-medullary avulsion are reported. This type of damage seems to be produced by severe hyperextension of the head on the neck with or without an additional rotational component.
Topics: Acceleration; Accidents, Traffic; Adolescent; Adult; Aged; Biomechanical Phenomena; Child; Female; Humans; Male; Medulla Oblongata; Middle Aged; Neck Injuries; Pons; Rotation
PubMed: 6581707
DOI: 10.1007/978-3-7091-4147-2_7 -
Brain Research Jun 1970
Topics: Animals; Cats; Cerebellum; Cerebral Cortex; Electric Stimulation; Evoked Potentials; Neural Pathways; Neurons; Pons
PubMed: 5433096
DOI: 10.1016/0006-8993(70)90172-1 -
Journal of Clinical Neuroscience :... Dec 2023Brainstem cavernomas occasionally require surgical treatment. Appropriate patient selection and thorough understanding of the anatomy and technical nuances involved in...
BACKGROUND
Brainstem cavernomas occasionally require surgical treatment. Appropriate patient selection and thorough understanding of the anatomy and technical nuances involved in microsurgical resection is a pre-requisite in undertaking these challenging cases.
CASE DESCRIPTION
We present a video case of a patient with a recurrent haemorrhagic pontine cavernoma. A step-by-step commentary of surgical footage is provided along with clinical, anatomical and technical learning points pertinent to the safe surgical management of these lesions.
Topics: Humans; Brain Stem Neoplasms; Microsurgery; Hemangioma, Cavernous; Pons; Hemorrhage
PubMed: 37883886
DOI: 10.1016/j.jocn.2023.10.001 -
The Journal of Comparative Neurology Feb 1979Cells that send ascending projections to the inferior colliculus were identified following injections of horseradish peroxidase into the colliculus. Labelled cells were...
Cells that send ascending projections to the inferior colliculus were identified following injections of horseradish peroxidase into the colliculus. Labelled cells were found in all subcollicular auditory nuclei. Virtually all cells of the ipsilateral ventral nucleus of the lateral lemniscus and medial superior olive appear to project to the colliculus. Very few cells in these nuclei were labelled on the contralateral side. Heavy labelling on the contralateral side was found in the dorsal nucleus of the lateral lemniscus and cochlear nucleus, with less labelling being found ipsilaterally in these nuclei. The lateral superior olive was approximately evenly labelled on the two sides, with about half the cells from each side projecting to each colliculus. Cells in all periolivary cell groups were labelled, with most being found adjacent to the medial superior olive. An effort was made to identify individual cell types that were labelled and some 24 cell types were identified. In the cochlear nucleus there were marked differences between cell types in the extent of their labelling. Topographic projections matched previously described tonotopic organization of the colliculus and all major subcollicular nuclei except the ventral nucleus of the lateral lemniscus. A description of the cells in the nucleus is provided.
Topics: Animals; Auditory Pathways; Brain Mapping; Cats; Cochlear Nerve; Inferior Colliculi; Olivary Nucleus; Pons
PubMed: 759446
DOI: 10.1002/cne.901830305 -
Brain Research. Brain Research Reviews Aug 1994The cholinergic pedunculopontine tegmental nucleus, located in the brainstem and part of the reticular formation, has been traditionally linked to motor function,... (Review)
Review
The cholinergic pedunculopontine tegmental nucleus, located in the brainstem and part of the reticular formation, has been traditionally linked to motor function, arousal and sleep. Its anatomical connections, however, raise the possibility that the pedunculopontine tegmental nucleus is also involved in other aspects of behaviour such as motivation, attention and mnemonic processes. This is of obvious importance, since the pedunculopontine tegmental nucleus undergoes degeneration in human neurodegenerative disorders also characterized by attentional and/or mnemonic deficits. Moreover, recent behavioural animal work suggests that cognitive processes may be represented in the pedunculopontine tegmental nucleus. The difficulty that faces research in this area, however is the possible influence of cognition by other processes, such as arousal state, motivation and motor function. Nevertheless, by reviewing the literature, the pedunculopontine tegmental nucleus seems to be involved in attentional and possibly also in learning processes. These processes could be mediated by influencing cortical function via the thalamus, basal forebrain and basal ganglia. The involvement of the pedunculopontine tegmental nucleus in mechanisms of memory, however, seems to be rather unlikely.
Topics: Animals; Cognition; Humans; Mesencephalon; Pons
PubMed: 7820134
DOI: 10.1016/0165-0173(94)90016-7 -
The Journal of Comparative Neurology Aug 1988The distribution of catecholamine-containing neurons, fibers, and varicosities in the brainstem of both adult and juvenile dogs was mapped in detail with glyoxylic acid...
The distribution of catecholamine-containing neurons, fibers, and varicosities in the brainstem of both adult and juvenile dogs was mapped in detail with glyoxylic acid histofluorescence. Four separate groups of catecholamine-fluorescent neurons were identified within the canine medulla and pons in locations comparable to the A1, A2, A5, and A6 regions reported in other species. However, aspects of the pattern and density of the catecholaminergic neuronal systems appeared to be unique to the dog. The A1 neurons of the caudal ventrolateral medulla were much more scattered than in rats or rabbits, but relatively similar to cats. In the A2 region of the dorsomedial medulla, catecholaminergic cells and fibers were uniquely distributed compared to other species: fluorescent neurons were scattered only within the dorsal motor nucleus of the vagus, and a distinctive pattern of fibers and varicosities outlined the nucleus of the solitary tract and dorsal motor nucleus of the vagus. The A5 neurons of the rostral ventrolateral medulla appeared at the rostral limit of the A1 region. Fluorescent A5 cells were more sparse than in rats or primates, and were patterned similarly to cats and rabbits. The canine A6 region contained the most extensive and dense grouping of catecholamine neurons and was similar in pattern to the rabbits but less extensive than that seen in cats or primates. An ascending catecholaminergic fiber pathway was traced through the central tegmental field of the canine medulla and pons, with features similar to the primate. The present study provides the first description of the catecholaminergic neuronal systems of the canine medulla.
Topics: Animals; Catecholamines; Dogs; Locus Coeruleus; Medulla Oblongata; Microscopy, Fluorescence; Neurons; Pons
PubMed: 3417906
DOI: 10.1002/cne.902740112