Cargando…
Comparative anatomy of dissected optic lobes, optic ventricles, midbrain tectum, collicular ventricles, and aqueduct: evolutionary modifications as potential explanation for non-tumoral aqueductal anomalies in humans
PURPOSE: An extensive literature has postulated multiple etiologies for aqueductal stenosis. No publications were found, discussing that evolutionary modifications might explain aqueductal anomalies. This study’s objectives were to review the evolutionary modifications of vertebrates’ tectum structu...
Autores principales: | , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Springer Berlin Heidelberg
2021
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8789712/ https://www.ncbi.nlm.nih.gov/pubmed/34812897 http://dx.doi.org/10.1007/s00381-021-05408-0 |
_version_ | 1784639832807440384 |
---|---|
author | Kier, E. Leon Kalra, Vivek B. Conlogue, Gerald J. Filippi, Cristopher G. Saluja, Sanjay |
author_facet | Kier, E. Leon Kalra, Vivek B. Conlogue, Gerald J. Filippi, Cristopher G. Saluja, Sanjay |
author_sort | Kier, E. Leon |
collection | PubMed |
description | PURPOSE: An extensive literature has postulated multiple etiologies for aqueductal stenosis. No publications were found, discussing that evolutionary modifications might explain aqueductal anomalies. This study’s objectives were to review the evolutionary modifications of vertebrates’ tectum structures that might explain human aqueduct anomalies. Undertaking vertebrate comparative study is currently not feasible in view of limitations in obtaining vertebrate material. Thus, vertebrate material collected, injected, dissected, and radiographed in the early 1970s was analyzed, focusing on the aqueduct and components of the midbrain tectum. METHODS: Photographs of brain dissections and radiographs of the cerebral ventricles and arteries of adult shark, frog, iguana, rabbit, cat, dog, and primate specimens, containing a barium-gelatin radiopaque compound, were analyzed focusing on the aqueduct, the optic ventricles, the quadrigeminal plate, and collicular ventricles. The anatomic information provided by the dissections and radiographs is not reproducible by any other radiopaque contrast currently available. RESULTS: Dissected and radiographed cerebral ventricular and arterial systems of the vertebrates demonstrated midbrain tectum changes, including relative size modifications of the mammalian components of the tectum, simultaneously with the enlargement of the occipital lobe. There is a transformation of pre-mammalian optic ventricles to what appear to be collicular ventricles in mammals, as the aqueduct and collicular ventricle form a continuous cavity. CONCLUSIONS: The mammalian tectum undergoes an evolutionary cephalization process consisting of relative size changes of the midbrain tectum structures. This is associated with enlargement of the occipital lobe, as part of overall neocortical expansion. Potentially, aqueductal anomalies could be explained by evolutionary modifications. |
format | Online Article Text |
id | pubmed-8789712 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Springer Berlin Heidelberg |
record_format | MEDLINE/PubMed |
spelling | pubmed-87897122022-02-02 Comparative anatomy of dissected optic lobes, optic ventricles, midbrain tectum, collicular ventricles, and aqueduct: evolutionary modifications as potential explanation for non-tumoral aqueductal anomalies in humans Kier, E. Leon Kalra, Vivek B. Conlogue, Gerald J. Filippi, Cristopher G. Saluja, Sanjay Childs Nerv Syst Original Article PURPOSE: An extensive literature has postulated multiple etiologies for aqueductal stenosis. No publications were found, discussing that evolutionary modifications might explain aqueductal anomalies. This study’s objectives were to review the evolutionary modifications of vertebrates’ tectum structures that might explain human aqueduct anomalies. Undertaking vertebrate comparative study is currently not feasible in view of limitations in obtaining vertebrate material. Thus, vertebrate material collected, injected, dissected, and radiographed in the early 1970s was analyzed, focusing on the aqueduct and components of the midbrain tectum. METHODS: Photographs of brain dissections and radiographs of the cerebral ventricles and arteries of adult shark, frog, iguana, rabbit, cat, dog, and primate specimens, containing a barium-gelatin radiopaque compound, were analyzed focusing on the aqueduct, the optic ventricles, the quadrigeminal plate, and collicular ventricles. The anatomic information provided by the dissections and radiographs is not reproducible by any other radiopaque contrast currently available. RESULTS: Dissected and radiographed cerebral ventricular and arterial systems of the vertebrates demonstrated midbrain tectum changes, including relative size modifications of the mammalian components of the tectum, simultaneously with the enlargement of the occipital lobe. There is a transformation of pre-mammalian optic ventricles to what appear to be collicular ventricles in mammals, as the aqueduct and collicular ventricle form a continuous cavity. CONCLUSIONS: The mammalian tectum undergoes an evolutionary cephalization process consisting of relative size changes of the midbrain tectum structures. This is associated with enlargement of the occipital lobe, as part of overall neocortical expansion. Potentially, aqueductal anomalies could be explained by evolutionary modifications. Springer Berlin Heidelberg 2021-11-23 2022 /pmc/articles/PMC8789712/ /pubmed/34812897 http://dx.doi.org/10.1007/s00381-021-05408-0 Text en © The Author(s) 2021 https://creativecommons.org/licenses/by/4.0/Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) . |
spellingShingle | Original Article Kier, E. Leon Kalra, Vivek B. Conlogue, Gerald J. Filippi, Cristopher G. Saluja, Sanjay Comparative anatomy of dissected optic lobes, optic ventricles, midbrain tectum, collicular ventricles, and aqueduct: evolutionary modifications as potential explanation for non-tumoral aqueductal anomalies in humans |
title | Comparative anatomy of dissected optic lobes, optic ventricles, midbrain tectum, collicular ventricles, and aqueduct: evolutionary modifications as potential explanation for non-tumoral aqueductal anomalies in humans |
title_full | Comparative anatomy of dissected optic lobes, optic ventricles, midbrain tectum, collicular ventricles, and aqueduct: evolutionary modifications as potential explanation for non-tumoral aqueductal anomalies in humans |
title_fullStr | Comparative anatomy of dissected optic lobes, optic ventricles, midbrain tectum, collicular ventricles, and aqueduct: evolutionary modifications as potential explanation for non-tumoral aqueductal anomalies in humans |
title_full_unstemmed | Comparative anatomy of dissected optic lobes, optic ventricles, midbrain tectum, collicular ventricles, and aqueduct: evolutionary modifications as potential explanation for non-tumoral aqueductal anomalies in humans |
title_short | Comparative anatomy of dissected optic lobes, optic ventricles, midbrain tectum, collicular ventricles, and aqueduct: evolutionary modifications as potential explanation for non-tumoral aqueductal anomalies in humans |
title_sort | comparative anatomy of dissected optic lobes, optic ventricles, midbrain tectum, collicular ventricles, and aqueduct: evolutionary modifications as potential explanation for non-tumoral aqueductal anomalies in humans |
topic | Original Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8789712/ https://www.ncbi.nlm.nih.gov/pubmed/34812897 http://dx.doi.org/10.1007/s00381-021-05408-0 |
work_keys_str_mv | AT kiereleon comparativeanatomyofdissectedopticlobesopticventriclesmidbraintectumcollicularventriclesandaqueductevolutionarymodificationsaspotentialexplanationfornontumoralaqueductalanomaliesinhumans AT kalravivekb comparativeanatomyofdissectedopticlobesopticventriclesmidbraintectumcollicularventriclesandaqueductevolutionarymodificationsaspotentialexplanationfornontumoralaqueductalanomaliesinhumans AT conloguegeraldj comparativeanatomyofdissectedopticlobesopticventriclesmidbraintectumcollicularventriclesandaqueductevolutionarymodificationsaspotentialexplanationfornontumoralaqueductalanomaliesinhumans AT filippicristopherg comparativeanatomyofdissectedopticlobesopticventriclesmidbraintectumcollicularventriclesandaqueductevolutionarymodificationsaspotentialexplanationfornontumoralaqueductalanomaliesinhumans AT salujasanjay comparativeanatomyofdissectedopticlobesopticventriclesmidbraintectumcollicularventriclesandaqueductevolutionarymodificationsaspotentialexplanationfornontumoralaqueductalanomaliesinhumans |