Talk:Neural - Pons Development
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Cite this page: Hill, M.A. (2024, April 26) Embryology Neural - Pons Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Neural_-_Pons_Development |
2017
The Long Journey of Pontine Nuclei Neurons: From Rhombic Lip to Cortico-Ponto-Cerebellar Circuitry
Front Neural Circuits. 2017 May 17;11:33. doi: 10.3389/fncir.2017.00033. eCollection 2017.
Kratochwil CF1,2, Maheshwari U3,4, Rijli FM3,4. Author information Abstract
The pontine nuclei (PN) are the largest of the precerebellar nuclei, neuronal assemblies in the hindbrain providing principal input to the cerebellum. The PN are predominantly innervated by the cerebral cortex and project as mossy fibers to the cerebellar hemispheres. Here, we comprehensively review the development of the PN from specification to migration, nucleogenesis and circuit formation. PN neurons originate at the posterior rhombic lip and migrate tangentially crossing several rhombomere derived territories to reach their final position in ventral part of the pons. The developing PN provide a classical example of tangential neuronal migration and a study system for understanding its molecular underpinnings. We anticipate that understanding the mechanisms of PN migration and assembly will also permit a deeper understanding of the molecular and cellular basis of cortico-cerebellar circuit formation and function. KEYWORDS:
Hox genes; cortico-ponto-cerebellar circuitry; pontine gray nuclei; precerebellar system; reticulotegmental nuclei
PMID:
28567005
PMCID:
PMC5434118
DOI:
10.3389/fncir.2017.00033
2015
Postnatal growth of the human pons: a morphometric and immunohistochemical analysis
J Comp Neurol. 2015 Feb 15;523(3):449-62. doi: 10.1002/cne.23690. Epub 2014 Dec 2.
Tate MC1, Lindquist RA, Nguyen T, Sanai N, Barkovich AJ, Huang EJ, Rowitch DH, Alvarez-Buylla A.
Abstract
Despite its critical importance to global brain function, the postnatal development of the human pons remains poorly understood. In the present study, we first performed magnetic resonance imaging (MRI)-based morphometric analyses of the postnatal human pons (0-18 years; n = 6-14/timepoint). Pons volume increased 6-fold from birth to 5 years, followed by continued slower growth throughout childhood. The observed growth was primarily due to expansion of the basis pontis. T2-based MRI analysis suggests that this growth is linked to increased myelination, and histological analysis of myelin basic protein in human postmortem specimens confirmed a dramatic increase in myelination during infancy. Analysis of cellular proliferation revealed many Ki67(+) cells during the first 7 months of life, particularly during the first month, where proliferation was increased in the basis relative to tegmentum. The majority of proliferative cells in the postnatal pons expressed the transcription factor Olig2, suggesting an oligodendrocyte lineage. The proportion of proliferating cells that were Olig2(+) was similar through the first 7 months of life and between basis and tegmentum. The number of Ki67(+) cells declined dramatically from birth to 7 months and further decreased by 3 years, with a small number of Ki67(+) cells observed throughout childhood. In addition, two populations of vimentin/nestin-expressing cells were identified: a dorsal group near the ventricular surface, which persists throughout childhood, and a parenchymal population that diminishes by 7 months and was not evident later in childhood. Together, our data reveal remarkable postnatal growth in the ventral pons, particularly during infancy when cells are most proliferative and myelination increases. © 2014 Wiley Periodicals, Inc. KEYWORDS: AB_2109815; AB_2304493; AB_2336877; AB_2336878; AB_261856; AB_291466; AB_304558; AB_396287; AB_442102; AB_91107; AB_92396; SciRes_000114; basis; brainstem; development; nif-0000-00217; pediatric; pontine glioma
PMID 25307966
2012
PMID 22888359
"The mammalian suck is the earliest-appearing somatic motor rhythm and is primarily controlled by a neural network known as the suck central pattern generator (sCPG). Suck appears in utero between 15 and 18 of weeks gestational age (GA) and the nonnutritive suck (NNS) is remarkably stable and well patterned by 32 weeks postmenstrual age (PMA) among healthy preterm infants ...The sCPG consists of bilateral, linked internuncial circuits within the brainstem pontine and medullary reticular formation [5–7]. Based on animal models, the minimal circuitries for ororhythmic activity reside between the trigeminal motor nucleus and the facial nucleus in the brainstem [7] and are situated to function as premotor inputs to lower motor neurons. The sCPG is modulated by multiple inputs, including descending pathways from sensorimotor cortex and reciprocal connections with the cerebellum [8, 9], which serve to modulate ororhythmic activity. "
2010
Anatomy of the brainstem: a gaze into the stem of life
Semin Ultrasound CT MR. 2010 Jun;31(3):196-219.
Angeles Fernández-Gil M, Palacios-Bote R, Leo-Barahona M, Mora-Encinas JP.
Radiology Department, Complejo Hospitalario Universitario de Badajoz, Hospital Infanta Cristina, Madrid, Spain. Abstract The brainstem has an ectodermal origin and is composed of 4 parts: the diencephalon, mesencephalon, pons, and medulla oblongata. It serves as the connection between the cerebral hemispheres with the medulla and the cerebellum and is responsible for basic vital functions, such as breathing, heartbeat blood pressure, control of consciousness, and sleep. The brainstem contains both white and gray matter. The gray matter of the brainstem (neuronal cell bodies) is found in clumps and clusters throughout the brainstem to form the cranial nerve nuclei, the reticular formation, and pontine nuclei. The white matter consists of fiber tracts (axons of neuronal cells) passing down from the cerebral cortex--important for voluntary motor function--and up from peripheral nerves and the spinal cord--where somatosensory pathways travel--to the highest parts of the brain. The internal structure of brainstem, although complex, presents a systematical arrangement and is organized in 3 laminae (tectum, tegmentum, and basis), which extend its entire length. The motor pathway runs down through the basis, which is located at the most anterior part. The cranial nerve nuclei are settled into the middle layer (the tegmentum), just in front of the 4th ventricle and are placed, from medial to lateral, on the basis of their function: somatic motor, visceral motor, visceral sensory, and somatic sensory. All the somatosensory tracts run upward to the thalamus crossing the tegmentum in front of the cranial nerve nuclei. The tectum, formed by the quadrigeminal plate and the medullary velum, contains no cranial nuclei, no tracts and no reticular formation. The knowledge of precise anatomical localization of a lesion affecting the brainstem is crucial in neurological diagnosis and, on this basis, is essential to be familiar with the location of the mayor tracts and nuclei appropriately. Nowadays, current magnetic resonance imaging techniques, although still macroscopic, allow the fine internal structure of the brainstem to be viewed directly and make it possible to locate the main intrinsic structures that justify the symptoms of the patient. In this article we discuss the anatomy of the brainstem and highlight the features and landmarks that are important in interpreting magnetic resonance imaging.
Copyright 2010 Elsevier Inc. All rights reserved.
PMID 20483389
http://www.semultrasoundctmri.com/article/S0887-2171(10)00026-0/abstract
2009
Cerebellar haemorrhages and pons development in extremely low birth weight infants
Front Biosci (Elite Ed). 2009 Jun 1;1:537-41.
Fumagalli M, Ramenghi LA, Righini A, Groppo M, Bassi L, De Carli A, Parazzini C, Triulzi F, Mosca F.
Neonatal Intensive Care Unit, Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Milan, University of Milan, Italy. Abstract Neuropathological and Magnetic Resonance Imaging (MRI) studies showed a high frequency of posterior fossa abnormalities in preterms. To assess whether cerebellar haemorrhages (CH) diagnosed with ultrasound and/or MRI affect pons development in ELBW infants. The anteroposterior diameter of the pons was measured manually on the midline sagittal T1 MR image in 75 ELBW babies consecutively scanned at term postmenstrual age. Subjects with CH were identified and compared to babies with no posterior fossa bleeding. Nine ELBW infants with CH (CH-Group: median gestational age -GA- 26 wks, range 23-27; birth weight -BW- 680 g, 425-980) were compared with 66 babies with normal cerebellum (Control-Group: GA 28 wks, 23-33; BW 815 g, 430-1000). The two groups were comparable for BW (p=0.088) while GA was significantly shorter in CH babies (p=0.005). The pontine diameter was significantly lower in CH-Group compared to Control-Group (12.8 +/- 2.2 vs 14.8 +/- 1.2 mm; p<0.001). CONCLUSIONS: Cerebellar haemorrhages seem to affect the development of the pons in ELBW with the youngest GA.
PMID 19482668
2007
Development of the pons in human fetuses
Congenit Anom (Kyoto). 2007 Jun;47(2):63-7.
Hatta T, Satow F, Hatta J, Hashimoto R, Udagawa J, Matsumoto A, Otani H.
Department of Developmental Biology, Faculty of Medicine, Shimane University, Izumo, Shimane, Japan. thatta@kanazawa-med.ac.jp Abstract Morphometric and histological studies of the pons were performed by light microscopy in 28 cases of externally normal human fetuses ranging from 90 to 246 mm in crown-rump length (CRL) and from 13 to 28 weeks of gestation. The brainstems of fetuses were embedded in celloidin or paraffin, and transverse sections were prepared. The pons was divided into two regions at the most ventral margin of the medial lemniscus at the level of the motor trigeminal nucleus. The relationships between the total dorsoventral length, ventral length, and dorsal length of the pons versus CRL and gestational ages were calculated, and empiric formulas were fitted. It was found that the ventral portion increased in size more rapidly than the dorsal portion. The proportion of the ventral portion in the total dorsoventral length was constitutively higher than that of the dorsal portion in the present range of CRL. In the pontine nuclei, from 235 mm in the CRL, some large cells with rich cytoplasm, pale nuclei, and a distinct nucleolus appeared on the dorsal side of the pyramidal tract. According to Weigert stained preparations, the first myelinated fibers in each motor root of the trigeminal, abducent, and facial nerves were recognized at 130-140 mm in CRL and the medial lemniscus at 230-235 mm.
PMID 17504389
http://onlinelibrary.wiley.com/doi/10.1111/j.1741-4520.2007.00145.x/abstract
2004
Development of the human fetal pons: in utero ultrasonographic study
Ultrasound Obstet Gynecol. 2004 Oct;24(5):506-10.
Achiron R, Kivilevitch Z, Lipitz S, Gamzu R, Almog B, Zalel Y.
Ultrasound Unit, Department of Obstetrics and Gynecology, Chaim Sheba Medical Center, Tel Hashomer and Sackler School of Medicine, Israel. rachiron@post.tau.ac.il
Abstract OBJECTIVES: To examine the ultrasonographic feasibility of imaging the fetal pons and to construct a reference chart for its normal development during gestation.
METHODS: A cross-sectional, prospective study on 293 healthy fetuses of low-risk pregnancies between 19 and 34 weeks was performed. The transfontanel approach, via the abdominal or vaginal routes, was used to evaluate the fetal metencephalon (pons and cerebellum). The anteroposterior diameter of the fetal pons was measured in a mid-sagittal plane. The longitudinal diameter of the cerebellar vermis was measured at the same plane and the vermis-pons ratio (VPR) was established.
RESULTS: One hundred and forty-four fetuses were in vertex position. In 140 (97.2%) satisfactory visualization and measurements of the pons and cerebellar vermis were obtained. One hundred and forty-nine fetuses were breech presentations and measurements were successfully performed in 147 (98.6%). The pons anteroposterior and vermis longitudinal diameters showed a linear correlation with gestational age (GA) (r = 0.95 for both measurements; P < 0.001). The mean VPR was 1.5 (+/-0.1 SD) and did not change in the gestational interval that was considered.
CONCLUSION: By using the transfontanel approach, evaluation of the fetal pons is feasible via the mid-sagittal plane. The nomograms developed and the ratio to fetal vermis provides reference data that may be helpful when evaluating anomalies of the brainstem.
PMID 15459939
2001
Identification of candidate genes for controlling development of the basilar pons by differential display PCR
Mol Cell Neurosci. 2001 Jul;18(1):1-12.
Gesemann M, Litwack ED, Yee KT, Christen U, O'Leary DD.
Molecular Neurobiology Laboratory, The Salk Institute, 10010 North Torrey Pines Road, San Diego, California 92037, USA. Abstract The basilar pons, a major hindbrain nucleus involved in sensory-motor integration, has become a model system for studying long-distance neuronal migration, axon-target recognition by collateral branching, and the formation of patterned axonal projections. To identify genes potentially involved in these developmental events, we have performed a differential display PCR screen comparing RNA isolated from the developing basilar pons with RNA obtained from developing cerebellum and olfactory bulb, as well as the mature basilar pons. Using 400 different combinations of primers, we screened more than 11,000 labeled DNA fragments and identified 201 that exhibited higher expression in the basilar pons than in the control tissues. From these, 138 distinct gene fragments were cloned. The differential expression of a large subset of these fragments was confirmed using RNase protection assays. In situ hybridization analysis revealed that the expression of many of these genes is limited to the basilar pons and only a few other brain regions, suggesting that they may play specific roles in pontine development.
Copyright 2001 Academic Press. PMID 11461149
