scholarly journals Atypical Brain Asymmetry in Human Situs Inversus: Gut Feeling or Real Evidence?

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 695
Author(s):  
Guy Vingerhoets ◽  
Robin Gerrits ◽  
Helena Verhelst
Keyword(s):  
Situs Inversus ◽  
Brain Asymmetry ◽  
General Mechanism ◽  
Vertebrate Species ◽  
Present Evidence ◽  
Brain Laterality ◽  
Morphological Asymmetry ◽  
Functional Laterality ◽  
Population Bias ◽  
The Brain

The alignment of visceral and brain asymmetry observed in some vertebrate species raises the question of whether this association also exists in humans. While the visceral and brain systems may have developed asymmetry for different reasons, basic visceral left–right differentiation mechanisms could have been duplicated to establish brain asymmetry. We describe the main phenotypical anomalies and the general mechanism of left–right differentiation of vertebrate visceral and brain laterality. Next, we systematically review the available human studies that explored the prevalence of atypical behavioral and brain asymmetry in visceral situs anomalies, which almost exclusively involved participants with the mirrored visceral organization (situs inversus). The data show no direct link between human visceral and brain functional laterality as most participants with situs inversus show the typical population bias for handedness and brain functional asymmetry, although an increased prevalence of functional crowding may be present. At the same time, several independent studies present evidence for a possible relation between situs inversus and the gross morphological asymmetry of the brain torque with potential differences between subtypes of situs inversus with ciliary and non-ciliary etiologies.

Neuroendocrine modulation of the “menopause”: insights into the aging brain

1999 ◽  
Vol 277 (6) ◽  
pp. E965-E970 ◽  
Author(s):  
Phyllis M. Wise
Keyword(s):  
Animal Models ◽  
Ovarian Follicles ◽  
Physiological Change ◽  
Menopausal Transition ◽  
Aging Brain ◽  
Neural Signals ◽  
Present Evidence ◽  
The Brain

The menopause marks the permanent end of fertility in women. It was once thought that this dramatic physiological change could be explained simply by the exhaustion of the reservoir of ovarian follicles. New data from studies performed in women and animal models make us reassess this assumption. An increasing body of evidence suggests that there are multiple pacemakers that contribute to the transition to irregular cycles, decreasing fertility, and the timing of the menopause. We will present evidence that lends credence to the possibility that a dampening and desynchronization of the precisely orchestrated neural signals lead to miscommunication between the brain and the pituitary-ovarian axis, and that this constellation of hypothalamic-pituitary-ovarian events leads to the deterioration of regular cyclicity and heralds menopausal transition.

scholarly journals Effects of ozone on sickness and depressive-like behavioral and biochemical phenotypes and their relations to serum amyloid A and kynurenine in blood

2021 ◽  
Author(s):  
Kristen K Baumann ◽  
Wei-Shan Sandy Liang ◽  
Daniel V Quaranta ◽  
Miranda L Wilson ◽  
Helina S Asrat ◽  
...  
Keyword(s):  
Serum Amyloid A ◽  
Pulmonary Inflammation ◽  
Kynurenine Pathway ◽  
Air Pollutant ◽  
Behavioral Changes ◽  
Serum Amyloid ◽  
Present Evidence ◽  
Dose Time ◽  
Amyloid A ◽  
The Brain

Ozone (O3) is an air pollutant which primarily damages the lungs, but growing evidence supports that O3 exposure can also affect the brain. Serum amyloid A (SAA) and kynurenine have been identified as circulating factors that are upregulated by O3, and both can contribute to depressive-like behaviors in mice. However, little is known about the relations of O3 exposure to sickness and depressive-like behaviors in experimental settings. In this study, we evaluated O3 dose-, time- and sex- dependent changes in circulating SAA in context of pulmonary inflammation and damage, sickness and depressive-like behavioral changes, and systemic changes in kynurenine and indoleamine 2,3-dioxygenase (IDO), an enzyme that regulates kynurenine production and contributes to inflammation-induced depressive-like behaviors. Our results in Balb/c and CD-1 mice showed that 3ppm O3, but not 2 or 1ppm O3, caused elevations in serum SAA and pulmonary neutrophils, and these responses resolved by 48 hours. Sickness and depressive-like behaviors were observed at all O3 doses (1-3ppm), although the detection of certain behavioral changes varied by dose. We also found that Ido1 mRNA expression was increased in the brain and spleen 24 hours after 3ppm O3, and that kynurenine was increased in blood. Together, these findings indicate that acute O3 exposure induces transient symptoms of sickness and depressive-like behaviors which may occur in the presence or absence of overt pulmonary neutrophilia and systemic increases of SAA. We also present evidence that the IDO/kynurenine pathway is upregulated systemically following an acute exposure to O3 in mice.

scholarly journals Patterns of brain asymmetry associated with polygenic risks for autism and schizophrenia implicate language and executive functions but not brain masculinization

2021 ◽  
Author(s):  
Zhiqiang Sha ◽  
Dick Schijven ◽  
Clyde Francks
Keyword(s):  
Sex Differences ◽  
Executive Functions ◽  
Autism Spectrum ◽  
Brain Asymmetry ◽  
Risk Scores ◽  
Imaging Data ◽  
Polygenic Risk ◽  
Left Right Asymmetry ◽  
The Uk ◽  
The Brain

AbstractAutism spectrum disorder (ASD) and schizophrenia have been conceived as partly opposing disorders in terms of systemizing versus empathizing cognitive styles, with resemblances to male versus female average sex differences. Left-right asymmetry of the brain is an important aspect of its organization that shows average differences between the sexes, and can be altered in both ASD and schizophrenia. Here we mapped multivariate associations of polygenic risk scores (PRS) for ASD and schizophrenia with asymmetries of regional cerebral cortical surface area, thickness and subcortical volume measures in 32,256 participants from the UK Biobank. PRS for the two disorders were positively correlated (r=0.08, p=7.13×10−50), and both were higher in females compared to males, consistent with biased participation against higher-risk males. Each PRS was associated with multivariate brain asymmetry after adjusting for sex, ASD PRS r=0.03, p=2.17×10−9, schizophrenia PRS r=0.04, p=2.61×10−11, but the multivariate patterns were mostly distinct for the two PRS, and neither resembled average sex differences. Annotation based on meta-analyzed functional imaging data showed that both PRS were associated with asymmetries of regions important for language and executive functions, consistent with behavioural associations that arose in phenome-wide association analysis. Overall, the results indicate that distinct patterns of subtly altered brain asymmetry may be functionally relevant manifestations of polygenic risk for ASD and schizophrenia, but do not support brain masculinization or feminization in their etiologies.

Role of spinal neurons in the maintenance of elevated sympathetic activity: a novel therapeutic target?

2020 ◽  
Vol 319 (3) ◽  
pp. R282-R287
Author(s):  
Maycon I. O. Milanez ◽  
Erika E. Nishi ◽  
Cássia T. Bergamaschi ◽  
Ruy R. Campos
Keyword(s):  
Cardiovascular Diseases ◽  
Therapeutic Target ◽  
Sympathetic Activity ◽  
Spinal Neurons ◽  
Potential Therapeutic Target ◽  
Present Evidence ◽  
Extensive Range ◽  
Vasomotor Activity ◽  
The Brain

The control of sympathetic vasomotor activity involves a complex network within the brain and spinal circuits. An extensive range of studies has indicated that sympathoexcitation is a common feature in several cardiovascular diseases and that strategies to reduce sympathetic vasomotor overactivity in such conditions can be beneficial. In the present mini-review, we present evidence supporting the spinal cord as a potential therapeutic target to mitigate sympathetic vasomotor overactivity in cardiovascular diseases, focusing mainly on the actions of spinal angiotensin II on the control of sympathetic preganglionic neuronal activity.

The fallacy of biphasic growth allometry for the vertebrate brain

2019 ◽  
Vol 128 (4) ◽  
pp. 1057-1067 ◽  
Author(s):  
Gary C Packard
Keyword(s):  
Analytical Study ◽  
Size Range ◽  
Single Equation ◽  
Vertebrate Species ◽  
Exponential Functions ◽  
Relative Growth ◽  
Brain Mass ◽  
Graphical Displays ◽  
Vertebrate Brain ◽  
The Brain

Abstract The concept of biphasic, loglinear growth of the vertebrate brain is based on graphical displays of logarithmic transformations of the original measurements. Such displays commonly give the appearance of two distinct mathematical distributions – one set of observations following a steep trajectory at the low end of the size range and another set following a shallow trajectory at the high end. However, the appearance of two distributions is an artefact resulting from the logarithmic transformations. Observations of brain mass vs. body mass in each of the eight vertebrate species examined in the current investigation conform to a single mathematical distribution that is well described by a single equation fitted to the original, untransformed data by non-linear regression. Data for carp, chickens, kangaroos and rabbits are described by three-parameter power equations whereas those for dolphins and primates are described by exponential functions that rise rapidly to a maximum. The brain continues to grow throughout life in carp, chickens, kangaroos and rabbits but not in dolphins and primates. Future investigations of relative growth of the brain should be based on graphical and analytical study of observations expressed on the native mathematical scale.

The Many Sides of Hemispheric Asymmetry: A Selective Review and Outlook

2017 ◽  
Vol 23 (9-10) ◽  
pp. 710-718 ◽  
Author(s):  
Michael C. Corballis ◽  
Isabelle S. Häberling
Keyword(s):  
Human Brain ◽  
Social Life ◽  
Hemispheric Asymmetry ◽  
Brain Asymmetry ◽  
Dual System ◽  
Animal Kingdom ◽  
Internal Organs ◽  
The Many ◽  
Two Sides ◽  
The Brain

AbstractHemispheric asymmetry is commonly viewed as a dual system, unique to humans, with the two sides of the human brain in complementary roles. To the contrary, modern research shows that cerebral and behavioral asymmetries are widespread in the animal kingdom, and that the concept of duality is an oversimplification. The brain has many networks serving different functions; these are differentially lateralized, and involve many genes. Unlike the asymmetries of the internal organs, brain asymmetry is variable, with a significant minority of the population showing reversed asymmetries or the absence of asymmetry. This variability may underlie the divisions of labor and the specializations that sustain social life. (JINS, 2017, 23, 710–718)

scholarly journals Rare variants in dynein heavy chain genes in two individuals with situs inversus and developmental dyslexia

2020 ◽  
Author(s):  
Andrea Bieder ◽  
Elisabet Einarsdottir ◽  
Hans Matsson ◽  
Harriet E. Nilsson ◽  
Jesper Eisfeldt ◽  
...  
Keyword(s):  
Heavy Chain ◽  
Developmental Dyslexia ◽  
Situs Inversus ◽  
Rare Variants ◽  
Autosomal Recessive Disorder ◽  
Copy Number Variations ◽  
Single Nucleotide Variants ◽  
Dynein Arms ◽  
Left Right Asymmetry ◽  
The Brain

ABSTRACTBackgroundDevelopmental dyslexia (DD) is a neurodevelopmental learning disorder with high heritability. A number of candidate susceptibility genes have been identified, some of which are linked to the function of the cilium, an organelle regulating left-right asymmetry development in the embryo. Furthermore, it has been suggested that disrupted left-right asymmetry of the brain may play a role in neurodevelopmental disorders such as DD.MethodsHere, we studied two individuals with co-occurring situs inversus (SI) and DD using whole genome sequencing to identify single nucleotide variants or copy number variations of importance for DD and SI.ResultsIndividual 1 had primary ciliary dyskinesia (PCD), a rare, autosomal recessive disorder with oto-sino-pulmonary phenotype and SI. We identified two rare nonsynonymous variants in the dynein axonemal heavy chain 5 gene (DNAH5): c.7502G>C;p.(R2501P), a previously reported variant predicted to be damaging and c.12043T>G;p.(Y4015D), a novel variant predicted to be damaging. Ultrastructural analysis of the cilia revealed a lack of outer dynein arms and normal inner dynein arms. MRI of the brain revealed no significant abnormalities. Individual 2 had non-syndromic SI and DD. In individual 2, one rare variant (c.9110A>G;p.(H3037R)) in the dynein axonemal heavy chain 11 gene (DNAH11), coding for another component of the outer dynein arm, was identified.ConclusionsWe identified the likely genetic cause of SI and PCD in one individual, and a possibly significant heterozygosity in the other, both involving dynein genes. Given the present evidence, it is unclear if the identified variants also predispose to DD, but further studies into the association are warranted.

scholarly journals INTRACELLULAR BRAIN REGENERATION: A NEW VIEW

2012 ◽  
Vol 67 (8) ◽  
pp. 21-25 ◽  
Author(s):  
A. A. Kubatiev ◽  
A. A. Pal'tsyn
Keyword(s):  
Functional Capacity ◽  
Chromatin Structure ◽  
Reparative Regeneration ◽  
Present Evidence ◽  
Brain Regeneration ◽  
A Cell ◽  
Neuron Regeneration ◽  
The Brain ◽  
Neuron Nucleus ◽  
New View

Mechanism of neuron regeneration in the cortex was discovered. Heterokaryon, a cell with two distinct nuclei, is formed by the fusion of neuron with oligodendrocyte. We showed that oligodendrocyte nucleus in heterokaryons is exposed to neuron-specific reprogramming. Oligodendrocyte nucleus becomes similar to neuron nucleus and in result of reprogramming is undefined from it according to morphology (size, shape, chromatin structure). Reprogrammed oligodendrocyte nuclei begin to express the neural specific markers NeuN and MAP2. Rate of transcription in the oligodendrocyte nuclei increases as in neurons. After completion of neuron-specific reprogrammin, second nucleus appears in neuron which increases the functional capacity of the cell. We present evidence that this process is the basis of physiological and reparative regeneration of the brain. 

scholarly journals No evidence that footedness in pheasants influences cognitive performance in tasks assessing colour discrimination and spatial ability

2020 ◽  
Vol 48 (1) ◽  
pp. 84-95 ◽  
Author(s):  
Mark A. Whiteside ◽  
Mackenzie M. Bess ◽  
Elisa Frasnelli ◽  
Christine E. Beardsworth ◽  
Ellis J.G. Langley ◽  
...  
Keyword(s):  
Cognitive Ability ◽  
Cognitive Performance ◽  
Individual Performance ◽  
Phasianus Colchicus ◽  
Spatial Learning And Memory ◽  
Stabilizing Selection ◽  
Human Species ◽  
Wide Range ◽  
Population Bias ◽  
The Brain

ABSTRACTThe differential specialization of each side of the brain facilitates the parallel processing of information and has been documented in a wide range of animals. Animals that are more lateralized as indicated by consistent preferential limb use are commonly reported to exhibit superior cognitive ability as well as other behavioural advantages. We assayed the lateralization of 135 young pheasants (Phasianus colchicus), indicated by their footedness in a spontaneous stepping task, and related this measure to individual performance in either 3 assays of visual or spatial learning and memory. We found no evidence that pronounced footedness enhances cognitive ability in any of the tasks. We also found no evidence that an intermediate footedness relates to better cognitive performance. This lack of relationship is surprising because previous work revealed that pheasants have a slight population bias towards right footedness, and when released into the wild, individuals with higher degrees of footedness were more likely to die. One explanation for why extreme lateralization is constrained was that it led to poorer cognitive performance, or that optimal cognitive performance was associated with some intermediate level of lateralization. This stabilizing selection could explain the pattern of moderate lateralization that is seen in most non-human species that have been studied. However, we found no evidence in this study to support this explanation.

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