Testing hypotheses of the evolution of encephalization in the Canidae (Carnivora, Mammalia)

Paleobiology ◽  
2008 ◽  
Vol 34 (1) ◽  
pp. 35-45 ◽  
Author(s):  
John A. Finarelli
Keyword(s):  
Brain Volume ◽  
Gradual Increase ◽  
Information Criterion ◽  
Allometric Relationships ◽  
Likelihood Ratios ◽  
Abrupt Increase ◽  
Complex Social Behavior ◽  
Volume Estimates ◽  
Endocranial Volume ◽  
The Brain

Evolutionary trends observed over large clades have the potential to mask underlying trends that occur within their constituent subclades. A recent study of encephalization in the Caniformia (Carnivora, Mammalia) found evidence for an abrupt increase in median log-encephalization quotients (logEQs), indicating higher brain volume relative to body mass, at the end-Miocene, but gradual increase in the variance of logEQs. In this study, new endocranial volume estimates for fossil taxa in the well-sampled caniform subclade Canidae are reported. Using the encephalization data for the Canidae, hypotheses of evolution in encephalization allometries were tested with respect to canid phylogeny. The Akaike Information Criterion and likelihood ratios recovered support for a preferred hypothesis of the evolution of canid encephalization, which proposed two distinct allometric relationships: (1) a plesiomorphic grade of encephalization in the subfamilies Hesperocyoninae and Borophaginae and the paraphyletic canine genus Leptocyon, and (2) an apomorphic grade in the crown radiation of Caninae. This defines a shift in to higher encephalization, but without an associated change in the variance around the allometry. Increased canid encephalization coincides with a reorganization of the brain and the observed trend may reflect the evolution of complex social behavior in this clade.

On the anatomic relation of choroid plexus to brain: a comparative study

1980 ◽  
Vol 238 (1) ◽  
pp. R76-R81 ◽  
Author(s):  
H. F. Cserr ◽  
M. Bundgaard ◽  
J. K. Ashby ◽  
M. Murray
Keyword(s):  
Choroid Plexus ◽  
Brain Volume ◽  
Brain Size ◽  
Ventricular Volume ◽  
Brain Weight ◽  
Air Breathing ◽  
Original Proposal ◽  
Adaptive Value ◽  
Choroid Plexuses ◽  
The Brain

The size of choroid plexuses and cerebral ventricles relative to brain varies widely among vertebrates. The functional significance of this variability has attracted little attention since Herrick's original proposal that large choroid plexuses might enhance oxygen delivery to the brain and therefore be of adaptive value in the transition of vertebrates from water to air breathing. We compared choroid plexus and brain weight or ventricular and brain volume in 40 species from nine vertebrate groups. Both choroid plexus weight and ventricular volume were unrelated to brain size. Plexus weight ranged from 0 to 5.2% of brain weight and ventricular volume from 0.9 to 132% of brain volume. Amid this diversity the dipnoans, chondrosteans, holosteans, amphibians, and crossopterygian examined in this study are exceptional in uniformly having large plexuses. The adaptive significance of large choroid plexuses may lie in the presence of specific homeostatic mechanisms and their role in the response to the increases in PCO2 that accompany the transition to air breathing.

scholarly journals The Effect of Intraventricular Hemorrhage on Brain Development in Premature Infants: A Synthetic MRI Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Chunxiang Zhang ◽  
Xin Zhao ◽  
Meiying Cheng ◽  
Kaiyu Wang ◽  
Xiaoan Zhang
Keyword(s):  
Relaxation Time ◽  
Premature Infants ◽  
Intraventricular Hemorrhage ◽  
Brain Volume ◽  
Relaxation Times ◽  
T2 Relaxation Time ◽  
T2 Relaxation ◽  
T1 And T2 ◽  
The Brain ◽  
Synthetic Mri

Objectives: Synthetic MRI can obtain multiple parameters in one scan, including T1 and T2 relaxation time, proton density (PD), brain volume, etc. This study aimed to investigate the parameter values T1 and T2 relaxation time, PD, and volume characteristics of intraventricular hemorrhage (IVH) newborn brain, and the ability of synthetic MRI parameters T1 and T2 relaxation time and PD to diagnose IVH.Materials and methods: The study included 50 premature babies scanned with conventional and synthetic MRI. Premature infants were allocated to the case group (n = 15) and NON IVH (n = 35). The T1, T2, PD values, and brain volume were obtained by synthetic MRI. Then we assessed the impact of IVH on these parameters.Results: In the posterior limbs of the internal capsule (PLIC), genu of the corpus callosum (GCC), central white matter (CWM), frontal white matter (FWM), and cerebellum (each p < 0.05), the T1 and T2 relaxation times of the IVH group were significantly prolonged. There were significant differences also in PD. The brain volume in many parts were also significantly reduced, which was best illustrated in gray matter (GM), cerebrospinal fluid and intracranial volume, and brain parenchymal fraction (BPF) (each p < 0.001, t = −5.232 to 4.596). The differential diagnosis ability of these quantitative values was found to be excellent in PLIC, CWM, and cerebellum (AUC 0.700–0.837, p < 0.05).Conclusion: The quantitative parameters of synthetic MRI show well the brain tissue characteristic values and brain volume changes of IVH premature infants. T1 and T2 relaxation times and PD contribute to the diagnosis and evaluation of IVH.

scholarly journals BrainFD: Measuring the Intracranial Brain Volume With Fractal Dimension

2021 ◽  
Vol 13 ◽  
Author(s):  
Ghulam Md Ashraf ◽  
Stylianos Chatzichronis ◽  
Athanasios Alexiou ◽  
Nikolaos Kyriakopoulos ◽  
Badrah Saeed Ali Alghamdi ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Brain Volume ◽  
Heterogeneous Data ◽  
Imaging Biomarker ◽  
Volume Loss ◽  
Imaging Data ◽  
Clinical Dementia Rating ◽  
Brain Volume Loss ◽  
Brain White Matter ◽  
The Brain

A few methods and tools are available for the quantitative measurement of the brain volume targeting mainly brain volume loss. However, several factors, such as the clinical conditions, the time of the day, the type of MRI machine, the brain volume artifacts, the pseudoatrophy, and the variations among the protocols, produce extreme variations leading to misdiagnosis of brain atrophy. While brain white matter loss is a characteristic lesion during neurodegeneration, the main objective of this study was to create a computational tool for high precision measuring structural brain changes using the fractal dimension (FD) definition. The validation of the BrainFD software is based on T1-weighted MRI images from the Open Access Series of Imaging Studies (OASIS)-3 brain database, where each participant has multiple MRI scan sessions. The software is based on the Python and JAVA programming languages with the main functionality of the FD calculation using the box-counting algorithm, for different subjects on the same brain regions, with high accuracy and resolution, offering the ability to compare brain data regions from different subjects and on multiple sessions, creating different imaging profiles based on the Clinical Dementia Rating (CDR) scores of the participants. Two experiments were executed. The first was a cross-sectional study where the data were separated into two CDR classes. In the second experiment, a model on multiple heterogeneous data was trained, and the FD calculation for each participant of the OASIS-3 database through multiple sessions was evaluated. The results suggest that the FD variation efficiently describes the structural complexity of the brain and the related cognitive decline. Additionally, the FD efficiently discriminates the two classes achieving 100% accuracy. It is shown that this classification outperforms the currently existing methods in terms of accuracy and the size of the dataset. Therefore, the FD calculation for identifying intracranial brain volume loss could be applied as a potential low-cost personalized imaging biomarker. Furthermore, the possibilities measuring different brain areas and subregions could give robust evidence of the slightest variations to imaging data obtained from repetitive measurements to Physicians and Radiologists.

scholarly journals Sleep apnoea in the asymptomatic elderly: a real issue for the brain?

2018 ◽  
Vol 51 (6) ◽  
pp. 1702450 ◽  
Author(s):  
Sébastien Celle ◽  
Claire Boutet ◽  
Cédric Annweiler ◽  
Jean-Claude Barthélémy ◽  
Frédéric Roche
Keyword(s):  
Cortical Thickness ◽  
Brain Volume ◽  
Sleep Apnoea ◽  
Middle Temporal Gyrus ◽  
Elderly Subjects ◽  
Brain Volumes ◽  
Control Subjects ◽  
Surface Control ◽  
The Brain ◽  
Local Brain

The link between sleep apnoea and brain structure is unclear; although dysfunction of the hippocampus, middle temporal gyrus and brainstem/cerebellum have been observed previously. However, this link has been little explored in elderly subjects. The aim of this study was to explore the link between sleep apnoea and the brain in an elderly population.226 asymptomatic elderly subjects (age mean±sd 75.3±0.9 years, range 72.3–77.8 years) from the PROOF (Evaluation of Ageing, Autonomic Nervous System Activity and Cardiovascular Events) cohort study were explored using linear voxel-based or cortical thickness with apnoea/hypopnoea index (AHI; mean±sd 15.9±11.5 events·h−1, range 6–63.6 events·h−1) as a covariate of main interest. The brain volumes of 20 control subjects, 18 apnoeic (AHI >29 events·h−1) treated patients and 20 apnoeic untreated patients from this population were compared using voxel-based morphometry, cortical thickness or surface-based analyses.AHI was not associated with any change in local brain volume, cortical thickness or cortex surface. Control subjects, apnoeic treated and untreated patients were not different in terms of local brain volume, cortical thickness or surface.In a specific population of asymptomatic elderly healthy subjects, sleep apnoea does not seem to be associated with a change in local brain volume or in cortical thickness.

Brain size/body weight in the dingo (Canis dingo): comparisons with domestic and wild canids

2017 ◽  
Vol 65 (5) ◽  
pp. 292 ◽  
Author(s):  
Bradley P. Smith ◽  
Teghan A. Lucas ◽  
Rachel M. Norris ◽  
Maciej Henneberg
Keyword(s):  
Body Size ◽  
Brain Size ◽  
Cuon Alpinus ◽  
Size Relationship ◽  
Wild Canids ◽  
Free Ranging ◽  
The Impact ◽  
Endocranial Volume ◽  
The Brain

Endocranial volume was measured in a large sample (n = 128) of free-ranging dingoes (Canis dingo) where body size was known. The brain/body size relationship in the dingoes was compared with populations of wild (Family Canidae) and domestic canids (Canis familiaris). Despite a great deal of variation among wild and domestic canids, the brain/body size of dingoes forms a tight cluster within the variation of domestic dogs. Like dogs, free-ranging dingoes have paedomorphic crania; however, dingoes have a larger brain and are more encephalised than most domestic breeds of dog. The dingo’s brain/body size relationship was similar to those of other mesopredators (medium-sized predators that typically prey on smaller animals), including the dhole (Cuon alpinus) and the coyote (Canis latrans). These findings have implications for the antiquity and classification of the dingo, as well as the impact of feralisation on brain size. At the same time, it highlights the difficulty in using brain/body size to distinguish wild and domestic canids.

Novel Multi-Linear Quantitative Brain Volume Formula For Manual Radiological Evaluation Of Brain Atrophy

2020 ◽  
Author(s):  
Richard Erasto Sungura ◽  
Emmanuel Abraham Mpolya ◽  
JM Spitsbergen ◽  
Callen Kwamboka Onyambu ◽  
Elingarami Sauli ◽  
...  
Keyword(s):  
Brain Atrophy ◽  
Quantitative Methods ◽  
Brain Volume ◽  
Northern Tanzania ◽  
Alternative Formula ◽  
Evans Index ◽  
Radiological Measurements ◽  
Technical Simplicity ◽  
Radiological Methods ◽  
The Brain

Abstract Background The brain is a dynamic organ that develops and involutes in volume. The process of volume loss known as brain atrophy commonly occurs in elderly. However, some conditions have been implicated to provoke this paradoxical process in childhood and making it important to have methods and techniques of quantifying brain volume. Automated quantitative methods are very important in brain atrophy assessment but these tools have limited availability in developing countries. The simplified linear radiological methods are poorly reproducible and hence there is a need to develop an alternative formula that is reproducible and applicable at all healthcare levels. Methods The multi-linear diagonal brain fraction formula (DBF) was designed from dimensions of brain relative to skull. To test a developed formula, a total of 347 subjects aged between 0 and 18 years who had brain CT scans performed at the health facilities in Northern Tanzania were recruited and subjected to a systematic measurement of their brains in a diagonal brain fashion. Results Out of 347 patients evaluated, 62 subjects (17.8%) were found to be cases of brain atrophy. The three radiological measurements which included sulcal width (SW), ventricular width (VW) and Evans Index (EI) were concurrently performed. SW and VW showed good age correlation while EI showed no significant correlation with age. Similar tests were extended to diagonal brain fraction (DBF) and skull vertical horizontal ratio (VHR) in which DBF showed significant correlation. Conclusions The DBF formula shows significant ability of differentiating changes of brain volume suggesting that it can be utilized as an alternative brain fraction quantification method bearing technical simplicity in assessing gross brain volume with the ability to classify degrees of brain atrophy into mild, moderate, severe and very severe stages.

scholarly journals Do Different Methods Yield Equivalent Estimations of Brain Size in Birds?

2020 ◽  
Vol 95 (2) ◽  
pp. 113-122
Author(s):  
Diego Ocampo ◽  
César Sánchez ◽  
Gilbert Barrantes
Keyword(s):  
Body Size ◽  
Brain Size ◽  
Brain Mass ◽  
Wide Range ◽  
Evolutionary Studies ◽  
Relative Brain Size ◽  
Using Data ◽  
Endocranial Volume ◽  
The Brain ◽  
Size Estimates

The ratio of brain size to body size (relative brain size) is often used as a measure of relative investment in the brain in ecological and evolutionary studies on a wide range of animal groups. In birds, a variety of methods have been used to measure the brain size part of this ratio, including endocranial volume, fixed brain mass, and fresh brain mass. It is still unclear, however, whether these methods yield the same results. Using data obtained from fresh corpses and from published sources, this study shows that endocranial volume, mass of fixed brain tissue, and fresh mass provide equivalent estimations of brain size for 48 bird families, in 19 orders. We found, however, that the various methods yield significantly different brain size estimates for hummingbirds (Trochilidae). For hummingbirds, fixed brain mass tends to underestimate brain size due to reduced tissue density, whereas endocranial volume overestimates brain size because it includes a larger volume than that occupied by the brain.

scholarly journals Long-Term Ultrasound Follow-Up of Thyroid Colloid Cysts

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Dong Wook Kim
Keyword(s):  
Gradual Increase ◽  
Acute Onset ◽  
Papillary Thyroid ◽  
Abrupt Increase ◽  
Interval Change ◽  
Thyroid Microcarcinoma ◽  
Colloid Cysts ◽  
Thyroid Colloid

Objective. This study aimed to assess the interval changes of thyroid colloid cysts (TCCs) by performing long-term ultrasound (US) follow-up examinations.Methods. From 2007 to 2008, 437 patients underwent a lobectomy for the treatment of papillary thyroid microcarcinoma. Among them, 268 patients underwent 4 or more postoperative US follow-ups after surgery. This study investigated the prevalence and interval changes of TCCs≥3 mm by using US follow-ups.Results. Among 268 patients, 35 (13.1%) had TCCs≥3 mm by a preoperative thyroid US, and 6 (2.2%) had newly detected TCCs at a US follow-up. Through long-term US follow-up, the interval changes for TCCs were classified as follows: no interval change (n=8), gradual increase (n=8), gradual decrease (n=5), positive fluctuation (n=3), negative fluctuation (n=6), disappearance (n=5), and new detection (n=6). None of the TCC cases had a TCC that was ≥10 mm at its largest diameter, and no patient complained of any relevant symptoms pertaining to the TCCs.Conclusions. In this study, TCCs demonstrated various interval changes, but no abrupt increase was found or acute onset of symptoms occurred.

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