scholarly journals Morphometric Analysis of Lungfish Endocasts Elucidates Early Dipnoan Palaeoneurological Evolution

2021 ◽  
Author(s):  
Alice M. Clement ◽  
T. J. Challands ◽  
Richard Cloutier ◽  
Laurent Houle ◽  
Per E. Ahlberg ◽  
...  
Keyword(s):  
Morphometric Analysis ◽  
Semicircular Canals ◽  
Sister Group ◽  
Data Set ◽  
X Ray ◽  
Phylogenetic Implications ◽  
The Central Nervous System ◽  
Indirect Information ◽  
The Brain ◽  
Insight Into

ABSTRACTLungfish (Dipnoi) are lobe-finned fish (Sarcopterygii) that have persisted for over 400 million years from the Devonian Period to present day. They are the extant sister group to tetrapods and thus have the ability to provide unique insight into the condition of the earliest tetrapods as well as their own evolutionary history. The evolution of their dermal skull and dentition is relatively well understood, but this is not the case for the central nervous system. While the brain itself has very poor preservation potential and is not currently known in any fossil lungfish, substantial indirect information about it and associated structures such as the inner ears can be obtained from the cranial endocast. However, before the recent development of X-ray tomography as a palaeontological tool, these endocasts could not be studied non-destructively, and few detailed studies were undertaken. Here we describe and illustrate the endocasts of six Palaeozoic lungfishes (Iowadipterus halli, Gogodipterus paddyensis, Pillararhynchus longi, Griphognathus whitei, Orlovichthys limnatis, and Rhinodipterus ulrichi) from tomographic scans. We combine these with six previously described lungfish endocasts (4 fossil and 2 recent taxa), also based on tomographic studies, into a 12-taxon data set for multivariate morphometric analysis using 17 variables. We find that the olfactory region appears to be more highly plastic than the hindbrain, and undergoes significant elongation in several taxa. Further, while the semicircular canals covary as an integrated module, the utriculus and sacculus of the inner ear instead vary independently of each other. The functional and phylogenetic implications of our findings are discussed.

scholarly journals NEUROANATOMÍA DEL SAURÓPODO TITANOSAURIO NARAMBUENATITAN PALOMOI DEL CRETÁCICO SUPERIOR DE PATAGONIA, ARGENTINA.

2020 ◽  
Author(s):  
Ariana Paulina-Carabajal ◽  
Leonardo Filippi ◽  
Fabien Knoll
Keyword(s):  
Semicircular Canal ◽  
Upper Cretaceous ◽  
Semicircular Canals ◽  
Lateral View ◽  
Phylogenetic Position ◽  
Posterior Semicircular Canal ◽  
X Ray ◽  
Anterior Semicircular Canal ◽  
X Ray Computed ◽  
The Brain

this taxon has uncertain phylogenetic relationships within the clade. An X-ray Computed Tomography (CT) scan of the holotypebraincase allowed the first reconstruction of the brain and inner ear of this taxon, making it possible to compare the neuroanatomy with thatof closely related forms. Except for the slightly sigmodal shape of the endocast in lateral view—considered a basal condition—, the brainshows derived titanosaurian traits such as a poorly developed dorsal expansion and a single exit for Cranial Nerve (CN) XII. In contrast, the innerear exhibits slender and long semicircular canals (the anterior semicircular canal is distinctly longer than the posterior semicircular canal), whichis a character present in more basal representatives of the group, such as Sarmientosaurus. We consider, however, the morphology of theinner ear as an unreliable indicator of phylogenetic position. Furthermore, there is a remarkable similarity between the morphology of theendocast of Narambuenatitanand the possible saltasaurid from (FAM 03.064), from the Upper Cretaceous of Fox-Amphoux-Métisson, France,suggesting saltasaurine affinities for the Argentinean taxon.

scholarly journals Braincase and Inner Ear Anatomy of the Late Carboniferous Tetrapod Limnoscelis dynatis (Diadectomorpha) Revealed by High-Resolution X-ray Microcomputed Tomography

2021 ◽  
Vol 9 ◽  
Author(s):  
Jozef Klembara ◽  
Marcello Ruta ◽  
Miroslav Hain ◽  
David S. Berman
Keyword(s):  
High Resolution ◽  
Semicircular Canals ◽  
Sister Group ◽  
Microcomputed Tomography ◽  
Data Matrix ◽  
Phylogenetic Position ◽  
Published Data ◽  
X Ray ◽  
Character Weighting ◽  
Anterior Semicircular Canal

The braincase anatomy of the Pennsylvanian diadectomorph Limnoscelis dynatis is described in detail, based upon high-resolution X-ray microcomputed tomography. Both supraoccipitals and most of the prootics and opisthotics are preserved. The known portions of the left prootic, opisthotic, and supraoccipital enclose complete sections of the endosseous labyrinth, including the anterior, posterior, and lateral semicircular canals, the vestibule, the cochlear recess, and the canal for the endolymphatic duct. The fossa subarcuata is visible anteromedial to the anterior semicircular canal. The presumed endolymphatic fossae occur in the dorsal wall of the posteromedial portion of the supraoccipital. Both the fossa subarcuata and the fossa endolymphatica lie in the cerebellar portion of the cranial cavity. In order to investigate the phylogenetic position of L. dynatis we used a recently published data matrix, including characters of the braincase, and subjected it to maximum parsimony analyses under a variety of character weighting schemes and to a Bayesian analysis. Limnoscelis dynatis emerges as sister taxon to L. paludis, and both species form the sister group to remaining diadectomorphs. Synapsids and diadectomorphs are resolved as sister clades in ∼90% of all the most parsimonious trees from the unweighted analysis, in the single trees from both the reweighted and the implied weights analyses, as well in the Bayesian tree.

scholarly journals First palaeoneurological study of a sauropod dinosaur from France and its phylogenetic significance

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7991 ◽  
Author(s):  
Fabien Knoll ◽  
Stephan Lautenschlager ◽  
Xavier Valentin ◽  
Verónica Díez Díaz ◽  
Xabier Pereda Suberbiola ◽  
...  
Keyword(s):  
Upper Cretaceous ◽  
Cranial Nerves ◽  
Semicircular Canals ◽  
Phylogenetic Position ◽  
Cerebral Vein ◽  
Southern France ◽  
X Ray ◽  
Computed Tomographic ◽  
X Ray Computed ◽  
The Brain

Despite continuous improvements, our knowledge of the palaeoneurology of sauropod dinosaurs is still deficient. This holds true even for Titanosauria, which is a particularly speciose clade of sauropods with representatives known from numerous Cretaceous sites in many countries on all continents. The data currently available regarding the palaeoneurology of titanosaurs is strongly biased towards Gondwanan forms (Argentina above all, but also India, Malawi and Australia). In contrast, the palaeoneurology of Laurasian titanosaurs is known only from a few taxa from Spain and Uzbekistan, despite the discovery in other countries of Laurasia of a number of neurocranial remains that would lend themselves well to investigations of this kind. To fill in this gap in our knowledge, we subjected a titanosaurian braincase from the uppermost Upper Cretaceous of southern France to X-ray computed tomographic scanning, allowing the generation of 3D renderings of the endocranial cavity enclosing the brain, cranial nerves and blood vessels, as well as the labyrinth of the inner ear. These reconstructions are used to clarify the phylogenetic position of the specimen from the Fox-Amphoux-Métisson site. A combination of characters, including the presence of two hypoglossal rami on the endocast, the average degree of development of the dorsal-head/caudal-middle-cerebral vein system and the relatively short and subequal lengths of the ipsilateral semicircular canals of the labyrinth, are particularly revealing in this respect. They suggest that, compared with the few other Laurasian titanosaurs for which in-depth palaeoneurological data are available, the French taxon is more derived than the distinctly more ancient, possibly non-lithostrotian titanosaur from the Uzbek site of Dzharakuduk but more basal than derived saltasaurids, such as the coeval or slightly more recent forms from the Spanish locality of Lo Hueco.

scholarly journals Restriction of Manganese Intake Prevents the Onset of Brain Manganese Overload in Zip14−/− Mice

2021 ◽  
Vol 22 (13) ◽  
pp. 6773
Author(s):  
Yuze Wu ◽  
Guojun Wei ◽  
Ningning Zhao
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Small Intestine ◽  
Neurological Disorders ◽  
The Body ◽  
Future Studies ◽  
The Central Nervous System ◽  
Manganese Transport ◽  
The Brain ◽  
Insight Into

As a newly identified manganese transport protein, ZIP14 is highly expressed in the small intestine and liver, which are the two principal organs involved in regulating systemic manganese homeostasis. Loss of ZIP14 function leads to manganese overload in both humans and mice. Excess manganese in the body primarily affects the central nervous system, resulting in irreversible neurological disorders. Therefore, to prevent the onset of brain manganese accumulation becomes critical. In this study, we used Zip14−/− mice as a model for ZIP14 deficiency and discovered that these mice were born without manganese loading in the brain, but started to hyper-accumulate manganese within 3 weeks after birth. We demonstrated that decreasing manganese intake in Zip14−/− mice was effective in preventing manganese overload that typically occurs in these animals. Our results provide important insight into future studies that are targeted to reduce the onset of manganese accumulation associated with ZIP14 dysfunction in humans.

scholarly journals Hippocampal Cb2 receptors: an untold story

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Robin Visvanathar ◽  
Maria Papanikolaou ◽  
Diana Aline Nôga ◽  
Marina Pádua-Reis ◽  
Adriano Bretanha Lopes Tort ◽  
...  
Keyword(s):  
Cannabinoid Receptors ◽  
Endocannabinoid System ◽  
Wide Distribution ◽  
Significant Progress ◽  
Medical Cannabis ◽  
Functional Roles ◽  
The Central Nervous System ◽  
Cb2 Receptors ◽  
The Brain ◽  
Insight Into

Abstract The field of cannabinoid research has been receiving ever-growing interest. Ongoing debates worldwide about the legislation of medical cannabis further motivates research into cannabinoid function within the central nervous system (CNS). To date, two well-characterized cannabinoid receptors exist. While most research has investigated Cb1 receptors (Cb1Rs), Cb2 receptors (Cb2Rs) in the brain have started to attract considerable interest in recent years. With indisputable evidence showing the wide-distribution of Cb2Rs in the brain of different species, they are no longer considered just peripheral receptors. However, in contrast to Cb1Rs, the functionality of central Cb2Rs remains largely unexplored. Here we review recent studies on hippocampal Cb2Rs. While conflicting results about their function have been reported, we have made significant progress in understanding the involvement of Cb2Rs in modulating cellular properties and network excitability. Moreover, Cb2Rs have been shown to be expressed in different subregions of the hippocampus, challenging our prior understanding of the endocannabinoid system. Although more insight into their functional roles is necessary, we propose that targeting hippocampal Cb2Rs may offer novel therapies for diseases related to memory and adult neurogenesis deficits.

scholarly journals Identification and expression of the lamprey Pax6 gene: evolutionary origin of the segmented brain of vertebrates

Development ◽  
2001 ◽  
Vol 128 (18) ◽  
pp. 3521-3531 ◽  
Author(s):  
Yasunori Murakami ◽  
Michio Ogasawara ◽  
Fumiaki Sugahara ◽  
Shigeki Hirano ◽  
Nori Satoh ◽  
...  
Keyword(s):  
Regulatory Gene ◽  
Sister Group ◽  
Pax6 Gene ◽  
Vertebrate Brain ◽  
Evolutionary Changes ◽  
Oral Ectoderm ◽  
Local Restriction ◽  
The Central Nervous System ◽  
The Brain

The Pax6 gene plays a developmental role in various metazoans as the master regulatory gene for eye patterning. Pax6 is also spatially regulated in particular regions of the neural tube. Because the amphioxus has no neuromeres, an understanding of Pax6 expression in the agnathans is crucial for an insight into the origin of neuromerism in the vertebrates. We have isolated a single cognate cDNA of the Pax6 gene, LjPax6, from a Lampetra japonica cDNA library and observed the pattern of its expression using in situ hybridization. Phylogenetic analysis revealed that LjPax6 occurs as an sister group of gnathostome Pax6. In lamprey embryos, LjPax6 is expressed in the eye, the nasohypophysial plate, the oral ectoderm and the brain. In the central nervous system, LjPax6 is expressed in clearly delineated domains in the hindbrain, midbrain and forebrain. We compared the pattern of LjPax6 expression with that of other brain-specific regulatory genes, including LjOtxA, LjPax2/5/8, LjDlx1/6, LjEmx and LjTTF1. Most of the gene expression domains showed conserved pattern, which reflects the situation in the gnathostomes, conforming partly to the neuromeric patterns proposed for the gnathostomes. We conclude that most of the segmented domains of the vertebrate brain were already established in the ancestor common to all vertebrates. Major evolutionary changes in the vertebrate brain may have involved local restriction of cell lineages, leading to the establishment of neuromeres.

scholarly journals Neuroanatomy of the nodosaurid Struthiosaurus austriacus (Dinosauria: Thyreophora) supports potential ecological differentiations within Ankylosauria

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Marco Schade ◽  
Sebastian Stumpf ◽  
Jürgen Kriwet ◽  
Christoph Kettler ◽  
Cathrin Pfaff
Keyword(s):  
Social Interactions ◽  
Semicircular Canals ◽  
Sister Group ◽  
Micro Ct ◽  
Lateral Semicircular Canal ◽  
Head Posture ◽  
Defensive Strategies ◽  
Horizontal Orientation ◽  
Ct Data ◽  
The Brain

AbstractNodosauridae is a group of thyreophoran dinosaurs characterized by a collar of prominent osteoderms. In comparison to its sister group, the often club-tailed ankylosaurids, a different lifestyle of nodosaurids could be assumed based on their neuroanatomy and weaponry, e.g., regarding applied defensive strategies. The holotype of the nodosaurid Struthiosaurus austriacus consists of a single partial braincase from the Late Cretaceous of Austria. Since neuroanatomy is considered to be associated with ecological tendencies, we created digital models of the braincase based on micro-CT data. The cranial endocast of S. austriacus generally resembles those of its relatives. A network of vascular canals surrounding the brain cavity further supports special thermoregulatory adaptations within Ankylosauria. The horizontal orientation of the lateral semicircular canal independently confirms previous appraisals of head posture for S. austriacus and, hence, strengthens the usage of the LSC as proxy for habitual head posture in fossil tetrapods. The short anterior and angular lateral semicircular canals, combined with the relatively shortest dinosaurian cochlear duct known so far and the lack of a floccular recess suggest a rather inert lifestyle without the necessity of sophisticated senses for equilibrium and hearing in S. austriacus. These observations agree with an animal that adapted to a comparatively inactive lifestyle with limited social interactions.

scholarly journals Organization of the Orexin/Hypocretin System in the Brain of Holostean Fishes: Assessment of Possible Relationships with Monoamines and Neuropeptide Y

2018 ◽  
Vol 91 (4) ◽  
pp. 228-251 ◽  
Author(s):  
Daniel Lozano ◽  
Agustín González ◽  
Jesús M. López
Keyword(s):  
Neuropeptide Y ◽  
Simultaneous Detection ◽  
Sister Group ◽  
Spotted Gar ◽  
Cell Groups ◽  
Actinopterygian Fishes ◽  
The Central Nervous System ◽  
Amia Calva ◽  
Lepisosteus Oculatus ◽  
The Brain

Holosteans form a small group of actinopterygian fishes considered the sister group of teleosts. Despite this proximity to the biggest group of vertebrates, relatively few studies have been conducted to investigate the organization of the central nervous system of this group of fishes. In this study, the neuroanatomical distribution of orexin/hypocretin-like immunoreactive (OX-ir) cell bodies and fibers was analyzed in the brain of 3 representative species of the 2 orders of extant holosteans, the spotted gar Lepisosteus oculatus, the Florida gar Lepisosteus platyrhincus, and the bowfin Amia calva. Antibodies against orexin-A (OXA) and orexin-B (OXB) were used, which labeled the same cells and fibers throughout the brain. In addition, double immunohistofluorescence was performed for the simultaneous detection of OXA and OXB with tyrosine hydroxylase, serotonin, and neuropeptide Y (NPY), in an attempt to localize the orexinergic structures precisely and study the possible interactions between these neuroactive substances. The pattern of distribution of OX-ir cells in the 3 species was largely similar, showing labeled cells in the preoptic area (POA), and the tuberal and retrotuberal hypothalamic regions, with only subtle differences between species in the density of labeled cells. OX-ir fibers were found in all main brain subdivisions of the 3 species, mostly in the ventral subpallial areas, POA, hypothalamus, posterior tubercle, thalamus, and mesencephalic tectum. Different densities of orexinergic fibers were observed in relation to catecholaminergic and serotoninergic cell groups, as well as an absence of colocalization between orexins and NPY in the same hypothalamic neurons. The comparison of these results with those obtained in other vertebrates highlights a constant pattern of distribution of this system of neurotransmission among different groups of actinopterygian fishes, especially in teleosts. Conserved features shared by all vertebrates studied were also observed, such as the presence of OX-ir cells in the basal hypothalamus, reflecting the preserved functions of these neuropeptides over the course of evolution.

XRF Study of Mexican Iron Gall Inks: Historical and Geographical Overview of their Chemistry

2014 ◽  
Vol 1618 ◽  
pp. 31-41 ◽  
Author(s):  
Jocelyn Alcántara García ◽  
Jose Luis Ruvalcaba Sil ◽  
Marie Vander Meeren
Keyword(s):  
Statistical Processing ◽  
Common Elements ◽  
Data Set ◽  
X Ray ◽  
Common Features ◽  
Northern Areas ◽  
History Of ◽  
Iron Gall ◽  
General Concern ◽  
Insight Into

ABSTRACTOver 2000 micro-X-Ray Fluorescence (μ-XRF) measurements of iron gall inks were collected at the General Archive of the Nation in Mexico (Archivo General de la Nación, AGN). The portable X-Ray system SANDRA permitted detection of common elements present in all iron gall inks (e.g. Ca, Fe, S, etc.) as well as characteristic traces and impurities (e.g. Cu, Ni, Zn, Pb, etc). The documents in the data set originate from all over Mexico and are dated between the 16th and 19th centuries. All manuscripts were well preserved.Extensive statistical processing of the relative X-Ray intensities revealed common features in groups of documents with the same provenance. Among the findings, there is a progressive trend to complex mixtures from the beginning of the 16th century to the 17th. A reverse trend was observed for the following century. Zinc, lead and seldom arsenic, chromium and mercury seem characteristic for northern areas whereas manganese seems common to the vast majority of studied inks.As a general concern in conservation research, special attention was addressed to copper, as it is known to have additive effects to the degradation of cellulose. This metal seems fairly common to Mexican inks, especially during 18th century.To the best of our knowledge, this is the first examination taken to such a large number of inks. This study contributes to the more-focused development of suitable treatments that tailor specific needs, since they are to be based on of ink’s composition. It sets a precedent for the study of these inks in the Americas and allows conservators and historians to gain further insight into the history of their usage in Mexico.

Difference Fourier Analysis of Glucose Embedded and Frozen Hydrated Purple Membrane

1982 ◽  
Vol 40 ◽  
pp. 74-75
Author(s):  
Jules S. Jaffe ◽  
Robert M. Glaeser
Keyword(s):  
Purple Membrane ◽  
Data Set ◽  
High Resolution Data ◽  
X Ray ◽  
X Ray Crystallography ◽  
Fourier Techniques ◽  
Versus Protein ◽  
The Difference ◽  
Difference Fourier ◽  
Ideal Method

Although difference Fourier techniques are standard in X-ray crystallography it has only been very recently that electron crystallographers have been able to take advantage of this method. We have combined a high resolution data set for frozen glucose embedded Purple Membrane (PM) with a data set collected from PM prepared in the frozen hydrated state in order to visualize any differences in structure due to the different methods of preparation. The increased contrast between protein-ice versus protein-glucose may prove to be an advantage of the frozen hydrated technique for visualizing those parts of bacteriorhodopsin that are embedded in glucose. In addition, surface groups of the protein may be disordered in glucose and ordered in the frozen state. The sensitivity of the difference Fourier technique to small changes in structure provides an ideal method for testing this hypothesis.

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