ObjectiveTo investigate the instant impact of hemodialysis on the cerebral morphological measurements of patients with end-stage renal disease.Materials and methodsTwenty-five patients undergoing maintenance HD and twenty-eight age-, sex-, and education-matched healthy control were included. The HD group and HC group had 3D high-resolution structural magnetic resonance imaging scans twice and once, respectively. Both groups underwent neuropsychologic tests. The morphological measurements of structural MRI were measured using CAT12 and these measures were compared among three groups. The relationship between morphological measures and (...) clinical parameters and neuropsychological tests were investigated through multiple regression analysis.ResultsCompared to the HC group, the cortical thickness before HD significantly decreased in the bilateral temporal lobe and significantly decreased in the left superior temporal gyrus after HD. The cortical thickness significantly increased in the bilateral temporal lobe, frontal lobe and occipital lobe after HD compared to before HD. The sulcus depth in the bilateral insula, frontal lobe, and parietal lobe after HD significantly increased compared to before HD. No significant differences in sulcus depth between HD and HC were detected. After HD, the cortical thickness of the right parsopercularis was positively correlated with the number connection test-A. Cortical thickness in multiple regions were positively correlated with blood flow velocity and cortical thickness in the left parahippocampal gyrus was negatively correlated with ultrafiltration volume. Patients showed better performance in the digit symbol test and line tracing test after HD compared to before HD, but there were no significant differences in the comparison of neuropsychologic tests between patients and HC.ConclusionThe instant morphological changes were captured during a single hemodialysis in HD patients. There was an association between these instant changes in the brain and clinical parameters and neuropsychologic tests. This work implied the instant impact of a single hemodialysis impact on the brain in HD patients. (shrink)

Neuroimaging is critical in the diagnosis and treatment of brain cancers; however, the first detection of tumors is a challenge. Detection techniques like image segmentation are heavily reliant on the segmented image’s resolution. Magnetic resonance imaging tumor segmentation has emerged as a new study area in the medical imaging field. This spongy and delicate mass of tissue is the brain. Stable conditions allow for patterns to enter and interact with each other. To put it simply, a tumor is (...) a mass of tissue that has grown unchecked by the natural mechanisms that keep it under control. When cells divide uncontrollably, they create a cancerous tumor. Brain tumors can be detected and segmented using a variety of methods. A new method for detecting brain tumors using MRI images is presented in this research. An innovative Woelfel filter is used for enhancement, and morphological segmentation approaches combined with anisotropic diffusion are used for segmentation. Segmentation of brain tumors can be accomplished using thresholding and morphological techniques, which are both effective. The tumor will be located and identified using morphological image processing. Image denoising refers to the process of removing artefacts such as noise and aliasing from digital images. Here MATLAB programming language is utilised as it incorporates all the toolboxes required for the application involved in the work. (shrink)

The blood‐brain barrier (BBB) is a complex structure formed by vascular endothelial cells, which serve to stabilize the homeostasic processes that are essential for neural functioning. The barrier relies on tight junctions between neighboring endothelial cells and a highly restricted passage of blood‐borne components through the endothelial lining. Selective transport mechanisms guarantee the essential import and export of metabolites through the BBB into and out of the neural microenvironment. The dual functions of barrier and carrier depend on distinct proteins, (...) some of which have been characterized in detail. (shrink)

The contribution of the body to cognition and control in natural and artificial agents is increasingly described as “off-loading computation from the brain to the body”, where the body is said to perform “morphological computation”. Our investigation of four characteristic cases of morphological computation in animals and robots shows that the ‘off-loading’ perspective is misleading. Actually, the contribution of body morphology to cognition and control is rarely computational, in any useful sense of the word. We thus distinguish (1) (...) morphology that facilitates control, (2) morphology that facilitates perception and the rare cases of (3) morphological computation proper, such as ‘reservoir computing.’ where the body is actually used for computation. This result contributes to the understanding of the relation between embodiment and computation: The question for robot design and cognitive science is not whether computation is offloaded to the body, but to what extent the body facilitates cognition and control – how it contributes to the overall ‘orchestration’ of intelligent behaviour. (shrink)

Elucidating distinct morphological atrophy patterns of Alzheimer’s disease and its prodromal stage, namely, mild cognitive impairment helps to improve early diagnosis and medical intervention of AD. On that account, we aimed to obtain distinct patterns of voxel-wise morphological atrophy and its further perturbation on structural covariance network in AD and MCI compared with healthy controls. T1-weighted anatomical images of matched AD, MCI, and HCs were included in this study. Gray matter volume was obtained using voxel-based morphometry and compared among three (...) groups. In addition, structural covariance network of identified brain regions exhibiting morphological difference was constructed and compared between pairs of three groups. Thus, patients with AD have a reduced hippocampal volume and an increased rate of atrophy compared with MCI and HCs. MCI exhibited a decreased trend in bilateral hippocampal volume compared with HCs and the accelerated right hippocampal atrophy rate than HCs. In AD, the hippocampus further exhibited increased structural covariance connected to reward related brain regions, including the anterior cingulate cortex, the putamen, the caudate, and the insula compared with HCs. In addition, the patients with AD exhibited increased structural covariance of left hippocampus with the bilateral insula, the inferior frontal gyrus, the superior temporal gyrus, and the cerebellum than MCI. These results reveal distinct patterns of morphological atrophy in AD and MCI, providing new insights into pathology of AD. (shrink)

ObjectiveThis study aimed to investigate the morphometric alterations in the cortical and subcortical structures in multiple system atrophy patients with mild cognitive impairment, and to explore the association with cognitive deficits.MethodsA total of 45 MSA patients and 29 healthy controls were recruited. FreeSurfer software was used to analyze cortical thickness, and voxel-based morphometry was used to analyze the gray matter volumes. Cortical thickness and gray matter volume changes were correlated with cognitive scores.ResultsCompared to healthy controls, both MSA subgroups exhibited widespread (...) morphology alterations of brain structures in the fronto-temporal regions. Direct comparison of MSA-MCI and MSA-only patients showed volume reduction in the left superior and middle temporal gyrus, while cortical thinning was found in the left middle and inferior temporal gyrus in MSA-MCI patients. Cortical thinning in the left middle temporal gyrus correlated with cognitive assessment and disease duration.ConclusionStructural changes in the brain occur in MSA-MCI patients. The alteration of brain structure in the left temporal regions might be a biomarker of cognitive decline in MSA-MCI patients. (shrink)

Registration of a series of the two-dimensional electron microscope images of the brain tissue into volumetric form is an important technique that can be used for neuronal circuit reconstruction. However, complex appearance changes of neuronal morphology in adjacent sections bring difficulty in finding correct correspondences, making serial section neural image registration challenging. To solve this problem, we consider whether there are such stable "markers" in the neural images to alleviate registration difficulty. In this paper, we employ the spherical (...) deformation model to simulate the local neuron structure and analyze the relationship between registration accuracy and neuronal structure shapes in two adjacent sections. The relevant analysis proves that regular circular structures in the section images are instrumental in seeking robust corresponding relationships. Then, we design a new serial section image registration framework driven by this neuronal morphological model, fully utilizing the characteristics of the anatomical structure of nerve tissue and obtaining more reasonable corresponding relationships. Specifically, we leverage a deep membrane segmentation network and neural morphological physical selection model to select the stable rounded regions in neural images. Then, we combine feature extraction and global optimization of correspondence position to obtain the deformation field of multiple images. Experiments on real and synthetic serial EM section neural image datasets have demonstrated that our proposed method could achieve more reasonable and reliable registration results, outperforming the state-of-the-art approaches in qualitative and quantitative analysis. (shrink)

This paper reports on the investigation of the effects of neuronal shape, at both individual cell and network level, on the behavior of neuronal systems. More specifically, two-dimensional biologically realistic neuronal networks are obtained that take explicity into account the position and morphology of neuronal cells, with the respective behavior for associative recall being simulated through a diluted version of Hopfield's model. While a specific probability density function is used for the placement of the cell bodies, images of real (...) neuronal cells (namely alpha and beta ganglion cells from the cat retina) are used to obtain biologically realistic models. Several morphological measures – including fractal dimension, the excluded volume, and integral geometry functionals–are estimated for the considered cells, and their values are correlated with the potential of the network for associative recall, which is quantified in terms of the overlap between distorted version of the trained patterns and their original version. Such an approach allows the quantitative and objective characterization of the relationship between neuronal shape and function, an important issue in neuroscience. The obtained results substantiate interesting relationships between the neural morphology and function as determined by the performance of the network. (shrink)

ObjectivePregnancy leads to long-lasting changes in brain structure for healthy women; however, little is known regarding alterations in the cortical features of pregnant women with malformed fetuses. Isolated clefts of the lip and/or palate (ICL/P) are the most common congenital anomaly in the craniofacial region, which is highly gene-associated. We speculated that pregnant women carrying fetuses with ICL/P may have associated risk genes and specific brain changes during pregnancy.MethodsIn this study, we investigated T1-weighted brain magnetic resonance imaging (...) data from 48 pregnant women: 24 women carrying fetuses with ICL/P (ICL/P group) and 24 women carrying normal fetuses (normal controls), then explored intergroup differences in gray matter volume (GMV), cortical thickness (CT) and cortical complexity (gyrification).ResultsCompared with controls, the ICL/P group had decreased total intracranial volume (TIV) than normal controls; besides, they exhibited increased GMV in the left cuneus, decreased GMV in the right superior temporal gyrus; increased CT in the left precuneus and left superior parietal gyrus, decreased CT involving parsopercularis, fusiform, middle temporal in the left hemisphere and supramarginal, precentral gyrus (PreCG) in the right hemisphere; increased gyrification in the left insula and PreCG, the left middle temporal, and the right supratemporal gyrus.ConclusionPregnant women with ICL/P fetuses had brain morphology changes involving language, auditory, vision, and sensory cortex, which may be their special brain changes compared to normal pregnant women. This study may provide clues for the early detection of fetuses with ICL/P, and be vital for preconception and prenatal counseling with non-invasive methods. (shrink)

This paper reports on the investigation of the effects of neuronal shape, at both individual cell and network level, on the behavior of neuronal systems. More specifically, two-dimensional biologically realistic neuronal networks are obtained that take explicity into account the position and morphology of neuronal cells, with the respective behavior for associative recall being simulated through a diluted version of Hopfield's model. While a specific probability density function is used for the placement of the cell bodies, images of real (...) neuronal cells (namely alpha and beta ganglion cells from the cat retina) are used to obtain biologically realistic models. Several morphological measures – including fractal dimension, the excluded volume, and integral geometry functionals–are estimated for the considered cells, and their values are correlated with the potential of the network for associative recall, which is quantified in terms of the overlap between distorted version of the trained patterns and their original version. Such an approach allows the quantitative and objective characterization of the relationship between neuronal shape and function, an important issue in neuroscience. The obtained results substantiate interesting relationships between the neural morphology and function as determined by the performance of the network. (shrink)

Cognition or higher brain activity is sometimes seen as a phenomenon greater than the sum of its parts. This viewpoint however is largely dependent on the state of the art of experimental techniques that endeavor to characterize morphology and its association to function. Retinal ganglion cells are readily accessible for this work and we discuss recent advances in computational techniques in identifying novel parameters that describe structural attributes possibly associated with specific function. These parameters are based on calculating (...) wavelet gradients from cell images followed by the extraction of meaningful measures including 2nd wavelet moment, entropy of orientation, and curvature. For the three cell types analyzed, the mean 2nd wavelet moment, which relates to the field of influence of the dendritic-tree segments was significantly different. cells had the highest mean 2nd wavelet moment, followed by the and cells (134 ± 22, 93 ± 19 and 63 ± 12, respectively). There was no significant difference between cells for entropy of orientation, indicating no class with a preferential orientation of their dendritic tree. Curvature provided similar results to the 2nd wavelet moment with cells having the highest curvature followed by and the cells (mean ± SD: 161 ± 15; 134 ± 22; 121 ± 15). Our feature space analysis also indicated a difference between these cell types. No difference was found between the and cell types and their physiological counterparts the Y and X cells based on wavelet analysis. Both the X and Y cells can be divided into two subtypes, the ON- and OFF-center cells based on the stratification level of the dendritic tree within the retina. Using 2nd wavelet moment, a difference in their morphological attributes, not reported previously, was noted for these subtypes. The 2nd wavelet moment and curvature are further discussed with respect to explaining regularity of spacing and coverage associated with retinal ganglion cell mosaics. (shrink)

“Morphological computation” is an increasingly important concept in robotics, artificial intelligence, and philosophy of the mind. It is used to understand how the body contributes to cognition and control of behavior. Its understanding in terms of "offloading" computation from the brain to the body has been criticized as misleading, and it has been suggested that the use of the concept conflates three classes of distinct processes. In fact, these criticisms implicitly hang on accepting a semantic definition of what constitutes (...) computation. Here, I argue that an alternative, mechanistic view on computation offers a significantly different understanding of what morphological computation is. These theoretical considerations are then used to analyze the existing research program in developmental biology, which understands morphogenesis, the process of development of shape in biological systems, as a computational process. This important line of research shows that cognition and intelligence can be found across all scales of life, as the proponents of the basal cognition research program propose. Hence, clarifying the connection between morphological computation and morphogenesis allows for strengthening the role of the former concept in this emerging research field. (shrink)

Objectives: Autism spectrum disorder (ASD) is a juvenile onset neurodevelopmental disorder with social impairment and stereotyped behavior as the main symptoms. Unaffected relatives may also exhibit similar ASD features due to genetic factors. Although previous studies have demonstrated atypical brain morphological features as well as task-state brain function abnormalities in unaffected parents with ASD children, it remains unclear the pattern of brain function in the resting state.Methods: A total of 42 unaffected parents of ASD children (pASD) and (...) 39 age-, sex-, and handedness-matched controls were enrolled. Multiple resting-state fMRI (rsfMRI) analyzing methods were applied, including amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), degree centrality (DC), and functional connectivity (FC), to reveal the functional abnormalities of unaffected parents in ASD-related brain regions. Spearman Rho correlation analysis between imaging metric values and the severity of ASD traits were evaluated as well.Results: ALFF, ReHo, and DC methods all revealed abnormal brain regions in the pASD group, such as the left medial orbitofrontal cortex (mOFC) and rectal gyrus (ROI-1), bilateral supplementary motor area (ROI-2), right caudate nucleus head and right amygdala/para-hippocampal gyrus (ROI-3). FC decreasing was observed between ROI-1 and right anterior cingulate cortex (ACC), ROI-2, and bilateral precuneus. FC enhancing was observed between ROI-3 and right anterior cerebellar lobe, left medial temporal gyrus, left superior temporal gyrus, left medial frontal gyrus, left precentral gyrus, right postcentral gyrus in pASD. In addition, ALFF values in ROI-1, DC values in ROI-3 were positively correlated with AQ scores in pASD (ρ1 = 0.298, P1 = 0.007; ρ2 = 0.220, P2 = 0.040), while FC values between ROI-1 and right ACC were negatively correlated with AQ scores (ρ3 = −0.334, P3 = 0.002).Conclusion: rsfMRI metrics could be used as biomarkers to reveal the underlying neurobiological feature of ASD for unaffected parents. (shrink)

Handaxe morphology is thought to be the first example of the imposition of arbitrary form. Handaxes may thus inform researchers about shared mental templates and evolving cognitive abilities. However, many factors, not related to changes in cognition (e.g., material type, function, resharpening processes), influence handaxe shape over time and space. Archaeologists must control for these factors before making inferences concerning cognition.

After a historical sketch of the dynamical hypothesis, we stress that it is a functionalist hypothesis. We then tackle the point of a dynamical approach to constituent structures and emphasize that dynamical modeling must be coupled with morphological analysis.

The nature of the relationship between mind and body is one of the greatest remaining mysteries. As such, the historical origin of the current dominant belief that mind is a function of the brain takes on especial significance. In this article I aim to explore and explain how and why this belief emerged in early 19th-century Britain. Between 1815 and 1819 two brain-based physiologies of mind were the subject of controversy and debate in Britain: the system of phrenology (...) devised by Franz Joseph Gall, and William Lawrence’s lectures at the Royal College of Surgeons. Both owed a profound intellectual debt to continental comparative anatomy. In the final quarter of the 18th-century, Johann Friedrich Blumenbach, Petrus Camper and Johann Gottfried von Herder had broken away from the traditional doctrine of the Great Chain of Being by allowing for a clear anatomical distinction between ‘man’ and beast based on the morphology of the skull. This reconceptualization of man as an anatomically distinct being gave Gall and Lawrence grounds to propose that the peculiarities of the human mind were dependent on mankind’s unique cerebral size and structure. (shrink)

The distinction between regular and irregular morphology is not clear-cut enough to suggest two distinct modular structures. Instead, regularity is tied directly to the type frequency of a pattern. Evidence from experiments as well as from naturally occurring sound change suggests that even regular forms have lexical storage. Finally, the development trajectory entailed by the dual-processing model is much more complex than that entailed by associative network models.

The shapes of neurons and glial cells dictate many important aspects of their functions. In olfactory systems, certain architectural features are characteristics of these two cell types across a wide variety of species. The accumulated evidence suggests that these common features may play fundamental roles in olfactoryinformation processing. For instance, the primary olfactory neuropil in most vertebrate and invertebrate olfactory systems is organized into discrete modules called glomeruli. Inside each glomerulus, sensory axons and CNS neurons branch and synapse in patterns (...) that are repeated across species. In many species, moreover, the glomeruli are enveloped by a thin and ordered layer of glial processes. Theglomerular arrangement reflects the processing of odor information in modules that encode the discrete molecular attributes of odorant stimuli being processed. Recent studies of the mechanisms that guide the development of olfactory neurons and glial cells have revealed complex reciprocal interactions between these two cell types, which may be necessary for the establishment of modular compartments. Collectively, the findings reviewed here suggest that specialized cellular architecture plays key functional roles in the detection, analysis, and discrimination of odors at early steps in olfactory processing. (shrink)

With the advancement of in vivo magnetic resonance imaging (MRI) technique, more detailed information about the human brain at high altitude (HA) has been revealed. The present review aimed to draw a conclusion regarding changes in the human brain in both unacclimatized and acclimatized states in a natural HA environment. Using multiple advanced analysis methods that based on MRI as well as electroencephalography, the modulations of brain gray and white matter morphology and the electrophysiological mechanisms underlying (...) processing of cognitive activity have been explored in certain extent. The visual, motor and insular cortices are brain regions seen to be consistently affected in both HA immigrants and natives. Current findings regarding cortical electrophysiological and blood dynamic signals may be related to cardiovascular and respiratory regulations, and may clarify the mechanisms underlying some behaviors at HA. In general, in the past 10 years, researches on the brain at HA have gone beyond cognitive tests. Due to the sample size is not large enough, the current findings in HA brain are not very reliable, and thus much more researches are needed. Moreover, the histological and genetic bases of brain structures at HA are also needed to be elucidated. (shrink)

A prefrontal control system that is less mature than the limbic reward system in adolescence is thought to impede self-regulatory abilities, which could contribute to poor dietary choices and obesity. We, therefore, aimed to examine whether structural morphology of the prefrontal cortex and the amygdala are associated with dietary decisions and obesity in children and adolescents. Seventy-one individuals between the ages of 8–22 years participated in this study; each participant completed a computer-based food choice task and a T1- and (...) T2-weighted structural brain scans. Two indices of obesity were assessed, including age- and sex-specific body mass index and waist-to-height ratio. The behavioral task included rating 60 food stimuli for tastiness, healthiness, and liking. Based on each participant’s self-ratings, 100 binary food choices were then made utilizing a computer mouse. Dietary “self-control” was calculated as the proportion of trials where the individual chose the healthier food item over the total number of trials. Cortical thickness and amygdala subnuclei volumes were quantified using FreeSurfer 6.0 and CIT168 atlas, respectively. We found that WHtR was negatively associated with the thickness of bilateral superior frontal, left superior temporal, right insula, and right inferior temporal regions. We also found WHtR to be positively associated with the volume of the central nucleus region of the amygdala, after adjusting for the hemisphere, age, sex, and intracranial volumes. A similar data pattern was observed when BMIz was used. Moreover, we found that across all participants, thinner right superior frontal cortex and larger left CEN volumes predicted lower dietary self-control. These results suggest that differential development of the PFC and amygdala relate to obesity and dietary self-control. Further longitudinal studies are merited to determine causal relationships among altered PFC to amygdala neural circuitry, dietary self-control, and obesity. (shrink)

The precise relationship between callosal morphology and specific connectivity is not yet known. Callosal axons are often presumed to be arranged according to their origin. In humans, this is true for the genu and the splenium, which convey axons from the prefrontal and occipital cortices, respectively, but not for the body, where axons from wide parts of the cortex are intermingled.

We agree with Frost that flexible letter-position coding is unlikely to be a universal property of word recognition across different orthographies. We argue that it is particularly unlikely in morphologically rich languages like Finnish. We also argue that dual-route models are not overly flexible and that they are well equipped to adapt to the linguistic environment at hand.

Analogy plays an important role in the production of irregular forms but the proposed Minimalist Morphology (MM) representations do not express this. Recent results also show that the regular forms of strong paradigms can have idiosyncratic properties that cannot be accounted for by MM. Methodological problems with an experiment are discussed and a plea for a processing explanation is made.

Müller's goal of bringing neuroscience to bear on controversies in linguistics is laudable. However, some of his specific proposals about innateness and autonomy are misguided. Recent studies on the neurobiology of regular and irregular inflectional morphology indicate that these two linguistic processes are subserved by anatomically and physiologically distinct neural subsystems, whose functional organization is likely to be under direct genetic control rather than assembled by strictly epigenetic factors.

Regular musical activity as a complex multimodal lifestyle activity is proposed to be protective against age-related cognitive decline and Alzheimer’s disease. This cross-sectional study investigated the association and interplay between musical instrument playing during life, multi-domain cognitive abilities and brain morphology in older adults from the DZNE-Longitudinal Cognitive Impairment and Dementia Study study. Participants reporting having played a musical instrument across three life periods were compared to controls without a history of musical instrument playing, well-matched for reserve proxies (...) of education, intelligence, socioeconomic status and physical activity. Participants with musical activity outperformed controls in global cognition, working memory, executive functions, language, and visuospatial abilities, with no effects seen for learning and memory. The musically active group had greater gray matter volume in the somatosensory area, but did not differ from controls in higher-order frontal, temporal, or hippocampal volumes. However, the association between gray matter volume in distributed frontal-to-temporal regions and cognitive abilities was enhanced in participants with musical activity compared to controls. We show that playing a musical instrument during life relates to better late-life cognitive abilities and greater brain capacities in OA. Musical activity may serve as a multimodal enrichment strategy that could help preserve cognitive and brain health in late life. Longitudinal and interventional studies are needed to support this notion. (shrink)

Robert Brain traces the origins of artistic modernism to specific technologies of perception developed in late-nineteenth-century laboratories. Brain argues that the thriving fin-de-siècle field of “physiological aesthetics,” which sought physiological explanations for the capacity to appreciate beauty and art, changed the way poets, artists, and musicians worked and brought a dramatic transformation to the idea of art itself.

We argue that although E-Z Reader does a good job in simulating many basic facts related to readers' eye movements, two phenomena appear to pose a challenge to the model. The first has to do with word length mediating the way compound words are identified; the second concerns the effects of initial fixation position in a word on eye behavior.

Frost's claim that universal models of reading require linguistically diverse data is relevant and justified. We support it with evidence demonstrating the extent of the bias towards some Indo-European languages and alphabetic scripts in scientific literature. However, some of his examples are incorrect, and he neglects the complex interaction of writing system and language structure with history and cultural environment.

Clahsen has added to the body of evidence that, on average, regular and irregular inflected words behave differently. However, the dual-mechanism account he supports predicts a crisp distinction; the empirical data instead suggest a fuzzy one, more in line with single-mechanism connectionist models.

Pericytes, like vascular smooth muscle cells, are perivascular cells closely associated with blood vessels throughout the body. Pericytes are necessary for vascular development and homeostasis, with particularly critical roles in the brain, where they are involved in regulating cerebral blood flow and establishing the blood-brain barrier. A role for pericytes during neurovascular disease pathogenesis is less clear—while some studies associate decreased pericyte coverage with select neurovascular diseases, others suggest increased pericyte infiltration in response to hypoxia or traumatic (...) class='Hi'>brain injury. Here, we used an endothelial loss-of-function Recombination signal binding protein for immunoglobulin kappa J region (Rbpj)/Notch mediated mouse model of brain arteriovenous malformation (AVM) to investigate effects on pericytes during neurovascular disease pathogenesis. We tested the hypothesis that pericyte expansion, via morphological changes, and Platelet-derived growth factor B/Platelet-derived growth factor receptor β (Pdgf-B/Pdgfrβ)-dependent endothelial cell-pericyte communication are affected, during the pathogenesis of Rbpj mediated brain AVM in mice. Our data show that pericyte coverage of vascular endothelium expanded pathologically, to maintain coverage of vascular abnormalities in brain and retina, following endothelial deletion of Rbpj. In Rbpj-mutant brain, pericyte expansion was likely attributed to cytoplasmic process extension and not to increased pericyte proliferation. Despite expanding overall area of vessel coverage, pericytes from Rbpj-mutant brains showed decreased expression of Pdgfrβ, Neural (N)-cadherin, and cluster of differentiation (CD)146, as compared to controls, which likely affected Pdgf-B/Pdgfrβ-dependent communication and appositional associations between endothelial cells and pericytes in Rbpj-mutant brain microvessels. By contrast, and perhaps by compensatory mechanism, endothelial cells showed increased expression of N-cadherin. Our data identify cellular and molecular effects on brain pericytes, following endothelial deletion of Rbpj, and suggest pericytes as potential therapeutic targets for Rbpj/Notch related brain AVM. (shrink)

Since the early 2000s, authoritarianism has risen as an increasingly powerful global phenomenon. This shift has not only social and political implications, but environmental implications too: authoritarian leaders seek to recast the relationship between society and the government in every aspect of public life, including environmental policy. When historians of technology or the environment have investigated the environmental consequences of authoritarian regimes, they have frequently argued that authoritarian regimes have been unable to produce positive environmental results or adjust successfully to (...) global structural change, if they have shown any concern for the environment at all. Put another way, the scholarly consensus holds that authoritarian regimes on both the left and the right generally have demonstrated an anti-environmentalist bias, and when opposed by environmentalist social movements, have succeeded in silencing those voices. This book explores the theme of environmental politics and authoritarian regimes on both the right and the left. The authors argue that in instances when environmentalist policies offer the possibility of bolstering a country's domestic (nationalist) appeal or its international prestige, authoritarian regimes can endorse and have endorsed environmental protective measures. The collection of essays analyse environmentalist initiatives pursued by authoritarian regimes, and provide explanations for both the successes and failures of such regimes. Looking at a range of case studies from a number of countries, including Brazil, China, Poland and Zimbabwe. (shrink)

This paper focuses on the make-up of different cultures in experimental neurology, neuroanatomy, and clinical psychiatry. These cultures served as important research bases for early regenerative concepts and projects in the area of neurology and psychiatry at the beginning of the 20th century. Nevertheless, the developments in brain research and clinical neurology cannot be regarded to be isolated from broader societal developments, as the discourses on social de- and regeneration, neurasthenia, nerve-weakness and experiences of the brain-injured after WWI (...) show. Societal and cultural developments directly influenced researchers’ conceptualisation, scientific ideas, and even their experimental and clinical orientation. They directly reflect which scientific problems the neuroscientists felt inclined to address and what areas they began to leave aside. Using the concept of socio-technical experiments, it is demonstrated that research methodologies in neuronal de- and regeneration studies were not simply a product of recent advances in the scientific differentiation of somatic neurology or brain-psychiatry. Moreover, they resulted in important interdisciplinary attempts which emerged from great collaborative work including neuroscientists from various areas of investigation in both basic and clinical contexts. (shrink)

Determining the brain properties that make people ‘brainier’ has moved well beyond early demonstrations that increasing intelligence correlates with increasing grey and white matter volumes. Both structural and functional in vivo neuroimaging techniques delineate a distributed network of brain regions, perhaps with a focus in the lateral prefrontal cortex, which varies in extent and connectivity with individual differences in intelligence. Longitudinal studies further show that the neuroanatomic correlates of intelligence are dynamic, changing most rapidly in early childhood. Several (...) promising candidate genes affecting neuronal development and neurotransmission have been proposed that might begin to explain the marked genetic overlap between cortical morphology and intelligence. A major future challenge is to determine the cellular events that underpin the neuroanatomic differences correlated with intelligence. BioEssays 29:962–973, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

The heated debate over whether there is only a single mechanism or two mechanisms for morphology has diverted valuable research energy away from the more critical questions about the neural computations involved in the comprehension and production of morphologically complex forms. Cognitive neuroscience data implicate many brain areas. All extant models, whether they rely on a connectionist network or espouse two mechanisms, are too underspecified to explain why more than a few brain areas differ in their activity (...) during the processing of regular and irregular forms. No one doubts that the brain treats regular and irregular words differently, but brain data indicate that a simplistic account will not do. It is time for us to search for the critical factors free from theoretical blinders. (shrink)

Background: In prior reports, we described the design and initial performance of a fully implantable, bi-directional neural interface system for use in deep brain and other neurostimulation applications. Here we provide an update on the chronic, long-term neural sensing performance of the system using traditional 4-contact leads and extend those results to include directional 8-contact leads.Methods: Seven ovine subjects were implanted with deep brain stimulation leads at different nodes within the Circuit of Papez: four with unilateral leads in (...) the anterior nucleus of the thalamus and hippocampus; two with bilateral fornix leads, and one with bilateral hippocampal leads. The leads were connected to either an Activa PC+S® or Percept PC°ledR deep brain stimulation and recording device. Spontaneous local field potentials, evoked potentials, LFP response to stimulation, and electrode impedances were monitored chronically for periods of up to five years in these subjects.Results: The morphology, amplitude, and latencies of chronic hippocampal EPs evoked by thalamic stimulation remained stable over the duration of the study. Similarly, LFPs showed consistent spectral peaks with expected variation in absolute magnitude dependent upon behavioral state and other factors, but no systematic degradation of signal quality over time. Electrode impedances remained within expected ranges with little variation following an initial stabilization period. Coupled neural activity between the two nodes within the Papez circuit could be observed in synchronized recordings up to 5 years post-implant. The magnitude of passive LFP power recorded from directional electrode segments was indicative of the contacts that produced the greatest stimulation-induced changes in LFP power within the Papez network.Conclusion: The implanted device performed as designed, providing the ability to chronically stimulate and record neural activity within this network for up to 5 years of follow-up. (shrink)

To identify the common and specific structural basis of bipolar depression and unipolar depression is crucial for clinical diagnosis. In this study, a total of 85 participants, including 22 BD patients, 36 UD patients, and 27 healthy controls, were enrolled. A voxel-based morphology method was used to identify the common and specific changes of the gray matter volume to determine the structural basis. Significant differences in GMV were found among the three groups. Compared with healthy controls, UD patients showed (...) decreased GMV in the orbital part of the left inferior frontal gyrus, whereas BD patients showed decreased GMV in the orbital part of the left middle frontal gyrus. Compared with BD, UD patients have increased GMV in the left supramarginal gyrus and middle temporal gyrus. Our results revealed different structural changes in UD and BD patients suggesting BD and UD have different neurophysiological underpinnings. Our study contributes toward the biological determination of morphometric changes, which could help to discriminate between UD and BD. (shrink)

Although contemporary sociologists of science have sometimes claimed Max Weber as a methodological precursor, they have not examined Weber's own writings about science. Between 1908 and 1912 Weber published a series of critical studies of the extension of scientific authority into public life. The most notable of these concerned attempts to implement the experimental psychology or psycho-physics laboratory in factories and other real-world settings. Weber's critique centered on the problem of social measurement. He emphasized the discontinuities between the space of (...) the laboratory and that of the factory, showing how several qualitative and historically conditioned differences between the two settings rendered the transfer of instruments and methods between them highly problematic. Weber's critical arguments prepared the ground for his greatest foray into empirical sociology, a survey he directed for the Verein für Sozialpolitik investigating the conditions and attitudes affecting the lives and performance of industrial workers. Using a different measuring instrument — the questionnaire — Weber tried to implement a concept of social measurement which implied a different ontology, drawn not from natural sciences but from the historical sciences. (shrink)