Minimal and normal-flow general anesthesia in patients undergoing surgery in prone position: impact on hemodynamics and regional cerebral oxygenation

Purpose: In this study, the aim to assess the combined effects of prone-positioning (PP) and minimal-flow (MF) general anesthesia on regional cerebral oxygenation (RCO) and systemic hemodynamics. Methods: This is a randomized prospective study aiming to evaluate changes in cerebral oxygenation and hemodynamic parameters in MF systemic anesthesia in patients undergoing surgery in PP. Patients were randomized to MF or normal-flow (NF) anesthesia. In the operating room, pulse rate, mean arterial pressure (MAP), peripheral hemoglobin oxygen saturation (spO2), and right- and left-side RCO (assessed by nearinfrared spectroscopy, NIRS) were measured perioperatively. Results: Overall, 46 patients were included (24 in the MF group and 22 in the NF group). The amount of anesthetic gas consumption was significantly lower in the low-flow (LF) group. In both groups, the mean pulse rate showed a decrease after PP. Before induction, RCO was significantly higher both at the right- and left-sides in the LF group compared to the NF group. This difference continued throughout the operation on the left-side and disappeared 10 min after intubation on the right-side. On the left side, mean RCO decreased after PP in both groups. Conclusion: MF anesthesia in PP did not reduce cerebral oxygenation compared to NF and was safe in terms of systemic hemodynamics and cerebral oxygenation.

Comparative study of the distribution and expression of Neuroglobin and Hypoxia-inducible factor-1α in the adult and young Yak Brain / Estudo comparativo da distribuição e expressão de neuroglobina e fator-1α indutível por hipóxia em adultos e jovens iaques (Yak Brain)

Background: The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. Aim: The study examined the expression of Neuroglobin (Ngb) and Hypoxia-inducible factor-1α (Hif-1α) in adult and young yak brain tissues, and provided researchers with meaningful insight into the anatomy, physiology, and biochemistry of this mammal. Method: The study employed immunohistochemistry (IHC), quantitative real-time PCR (qRT-PCR), and Western blot (WB) to obtain the results. Results: Ngb and Hif-1α were significantly (P<0.05) expressed in the cerebellar cortex, piriform lobe, medulla, and corpus callosum of the adult yak while in the young yak brain tissues, the protein expressions were significantly found in the white matter of the cerebellum, pineal gland, corpus callosum, and cerebellar cortex. The Ngb and Hif-1α expression showed similarities and differences. This may have resulted from similar animal species, source of nutrition, age factors, brain size, emotional activities, and communication. The findings documented that Ngb and Hif-1α are commonly expressed in various adult and young yak brain tissues. Multiple roles in the brain tissues of the adult and young yaks are involved in the expression and distribution and are proposed to play a significant role in the adaptation of the yak to the high altitude environment. Conclusion: This study provides meaningful data to understand the adaptive mechanism to hypoxia and recommended researchers to expand on the adaptive mechanism and brain tissues that are not recorded.

Contexto: O cérebro é um órgão que funciona como o centro do sistema nervoso em todos os animais vertebrados e na maioria dos invertebrados. Objetivo: O estudo examinou a expressão de neuroglobina (Ngb) e fator-1α indutível por hipóxia (Hif-1α) em tecidos cerebrais de iaques adultos e jovens e forneceu aos pesquisadores uma visão significativa da anatomia, fisiologia e bioquímica desse mamífero. Método: O estudo utilizou imuno-histoquímica (IHC), PCR quantitativo em tempo real (qRT-PCR) e western blot (WB) para a obtenção dos resultados. Resultados: Ngb e Hif-1α foram significativamente (P < 0,05) expressos no córtex cerebelar, lobo piriforme, medula e corpo caloso do iaque adulto, enquanto nos tecidos cerebrais do iaque jovem as expressões proteicas foram encontradas significativamente na substância branca do cerebelo, glândula pineal, corpo caloso e córtex cerebelar. A expressão de Ngb e Hif-1α apresentou semelhanças e diferenças. Isso pode ter resultado de espécies animais semelhantes, fonte de nutrição, fatores de idade, tamanho do cérebro, atividades emocionais e comunicação. Os resultados documentaram que o Ngb e o Hif-1α são comumente expressos em vários tecidos cerebrais de iaques adultos e jovens. Múltiplos papéis nos tecidos cerebrais de iaques adultos e jovens estão envolvidos na expressão e distribuição e são propostos para desempenhar um papel significativo na adaptação do iaque ao ambiente de alta altitude. Conclusão: Este estudo fornece dados significativos para compreender o mecanismo adaptativo à hipóxia e recomendou que os pesquisadores expandissem o mecanismo adaptativo e os tecidos cerebrais que não foram registrados.

Uncovering a 'sensitive window' of multisensory and motor neuroplasticity in the cerebrum and cerebellum of male and female starlings.

Traditionally, research unraveling seasonal neuroplasticity in songbirds has focused on the male song control system and testosterone. We longitudinally monitored the song behavior and neuroplasticity in male and female starlings during multiple photoperiods using Diffusion Tensor and Fixel-Based techniques. These exploratory data-driven whole-brain methods resulted in a population-based tractogram confirming microstructural sexual dimorphisms in the song control system. Furthermore, male brains showed hemispheric asymmetries in the pallium, whereas females had higher interhemispheric connectivity, which could not be attributed to brain size differences. Only females with large brains sing but differ from males in their song behavior by showing involvement of the hippocampus. Both sexes experienced multisensory neuroplasticity in the song control, auditory and visual system, and cerebellum, mainly during the photosensitive period. This period with low gonadal hormone levels might represent a 'sensitive window' during which different sensory and motor systems in the cerebrum and cerebellum can be seasonally re-shaped in both sexes.

Curbing action potential generation or ATP-synthase leads to a decrease in in-cell pyruvate dehydrogenase activity in rat cerebrum slices.

Direct and real-time monitoring of cerebral metabolism exploiting the drastic increase in sensitivity of hyperpolarized 13C-labeled metabolites holds the potential to report on neural activity via in-cell metabolic indicators. Here, we followed the metabolic consequences of curbing action potential generation and ATP-synthase in rat cerebrum slices, induced by tetrodotoxin and oligomycin, respectively. The results suggest that pyruvate dehydrogenase (PDH) activity in the cerebrum is 4.4-fold higher when neuronal firing is unperturbed. The PDH activity was 7.4-fold reduced in the presence of oligomycin, and served as a pharmacological control for testing the ability to determine changes to PDH activity in viable cerebrum slices. These findings may open a path towards utilization of PDH activity, observed by magnetic resonance of hyperpolarized 13C-labeled pyruvate, as a reporter of neural activity.

Funciones ejecutivas: una revisión de su fundamentación teórica / Executive functions: a review of their theoretical basis

El presente artículo busca establecer los fundamentos de las funciones ejecutivas (FE) a nivel conceptual, para lo cual se plantea el seguimiento de los siguientes elementos: a) definición de las funciones cerebrales inferiores y superiores; b) relación entre FE y estructura anatomo-funcional; y c) confluencia final de las FE en un modelo integrador. a) Las funciones cerebrales inferiores están ligadas a los procesos más primitivos del ser humano. Permiten la satisfacción de necesidades básicas para la supervivencia; por tanto, se refieren a las capacidades adquiridas genéticamente sin que para su ejecución medie ningún proceso de aprendizaje. Por su parte, las funciones cerebrales superio-res se emparentan con los procesos neuropsicológicos bajo los cuales se sustenta la capacidad de modificar el ambiente y las circunstancias. Lo anterior ocurre gracias a: memoria, atención, lenguaje, razonamiento abstracto, actos gestuales y funciones ejecutivas (Rodríguez et al., 2006). Estas funciones cerebrales son el fundamento de las FE. b) Frente a su localización anatómica y funcional, Goldberg (2001) determina los lóbulos frontales como principal sustrato, por cuanto representan el centro ejecutivo del cerebro y la porción cerebral con mayor evolución de la corteza. Estos son los en-cargados de recibir la información de los estímulos y de la totalidad de las modalidades sensoriales. c) La anterior conceptualización permite definir las FE como un conjunto de capacidades referidas a la formulación de metas, planificación para el logro de dichas metas y la ejecución de la conducta de manera eficaz (Lezak, 1982).

This article seeks to establish the foundations of executive functions (EF) at a conceptual level, for which the following elements are proposed: a) definition of lower and higher brain functions; b) relationship between EF and anatomical-functional structure; and c) final confluence of EF in an integrative model. a) Lower brain functions are linked to the most primitive processes of the human being. They allow the satisfaction of basic needs for survival; therefore, they refer to genetically acquired capacities without any learning process for their execution. On the other hand, higher brain functions are related to the neuropsychological processes under which the capacity to modify the environment and circumstances is sustained. This occurs thanks to: memory, attention, language, abstract reasoning, gestural acts and executive functions (Rodriguez et al., 2006). These brain functions are the foundation of EF. b) Regarding its anatomical and functional location, Goldberg (2001) determines the frontal lobes as the main substrate, since they represent the executive center of the brain and the cerebral portion with the highest evolution of the cortex. These are responsible for receiving information from stimuli and from the totality of sensory modalities. c) The above conceptualization allows defining EF as a set of capacities referred to the formulation of goals, planning for the achievement of these goals and the execution of behavior in an effective manner (Lezak, 1982).

Cortical Brain Functions ­ The Brodmann Legacy in the 21st Century

In 1909, Korbinian Brodmann described 52 functional brain areas, 43 of them found in the human brain. More than a century later, his devoted functional map was incremented by Glasser et al in 2016, using functional nuclear magnetic resonance imaging techniques to propose the existence of 180 functional areas in each hemisphere, based on their cortical thickness, degree of myelination (cortical myelin content), neuronal interconnection, topographic organization, multitask answers, and assessment in their resting state. This opens a huge possibility, through functional neuroanatomy, to understand a little more about normal brain function and its functional impairment in the presence of a disease.

Mecanismos Neurocognitivos de la motivación en el entrenamiento físico / Neurocognitive mechanisms of motivation in physical training

La inactividad física y el sedentarismo son en la actualidad un problema de salud global que preocupa por su crecimiento sistemático. Provoca consecuencias sanita-rias en los adultos y, con un incremento alarmante, en la población más joven. Por el contrario, la realización periódica de actividad física ha demostrado beneficios a la salud física, neurológica y mental. A pesar de los incontrovertibles datos sobre sus efectos positivos, menos de la mitad de la población mundial se ejercita regularmen-te. El objetivo de este trabajo es realizar una breve descripción sobre los mecanismos neurocognitivos que se encuentran implicados en los procesos de motivación, en es-pecial los que se vinculan a la actividad física, con la finalidad de presentar una serie de recomendaciones pragmáticas para aumentar la adherencia a programas de en-trenamiento físico, basados en técnicas de la psicología cognitiva y analizados desde la perspectiva neurocognitiva.

Physical inactivity and sedentary lifestyle are currently a global health problem that concerns because of its systematic growth, the health consequences it causes for adults and, in alarming escalation, also for the younger population. On the contrary, regu-lar physical activity has shown benefits to physical, neurological and mental health. Despite the incontrovertible information about its positive effects, less than half of the world's population excercises regularly. This work's objective is to make a brief description of the neurocognitive mechanisms that are involved in the motivational processes, especially those linked to physical activity, in order to present pragmatic recommendations that increase adherence to physical training programs, based on techniques of cognitive psychology and analyzed from a neurocognitive perspective.

Cerebro y procesos cognitivos bajo la influencia de la música de orquesta sinfónica / Brain and cognitive processes under the influence of symphonic orchestra music / Cérebro e processos cognitivos sob a influência da música da orquestra sinfônica

Esta investigación tuvo como objetivo determinar las características funcionales del cerebro de intérpretes y oyentes de música sinfónica. Para esto, se desarrolló una investigación cuantitativa con diseño comparativo-correlacional. Participaron 120 personas distribuidas en 3 grupos: intérpretes, oyentes y controles; siendo equiparables en edad, género y escolaridad. Los intérpretes presentaron déficit en fluidez verbal de tipo semántico y dificultades en planeación, sin embargo, tuvieron mayor desempeño en tareas de memoria visual, atención, y velocidad de procesamiento de la información, en comparación con quienes sólo oyeron la música y más aún con quienes no se expusieron a este tipo de música. Por su parte los oyentes presentaron compromiso en comprensión de la información y mejor memoria verbal, así como organización de tipo ejecutivo y fluidez fonológica. Así, la influencia de la música sinfónica sobre el funcionamiento de los procesos neurocognitivos varía y depende de la forma en que se exponga el individuo a ésta, lo que también determinará el efecto que se tendrá sobre sufuncionamiento cerebral, puesto que, para algunas funciones cerebrales, interpretar el instrumento musical aumenta y mejora el desempeño del proceso cognitivo, y para otras funciones, es el oír la música, y no el interpretar el instrumento, lo que favorece un mayor desempeño. Independientemente de esto, sedeterminó, que hay una ventaja en los resultados de la función cerebral en aquellas personas que se exponen a este tipo de música orquestal, ya sea como parte de la orquesta o como oyente de la melodía.

This research aimed to determine the functional characteristics of the brain of interpreters and people who listen to symphonic music. With this in mind, a quantitative research with comparative-correlational design was developed. 120 people participated in three different groups: interpreters, listeners and controls; being comparable in age, gender and schooling. The interpreters presented deficits in verbal fluency of semantic type and difficulties in planning, however, they have greater performance in tasks of visual memory, attention, and speed of information processing, in comparison with those who only listen to music and even more with those who are not exposed to this type of music. The listeners presented a commitment to understanding information and better verbal memory, as well as an organization of executive type and phonological fluency. Thus, the influence of symphonic music, on the functioning of neurocognitive processes, varies and depends on the way in which the individual is exposed to it, and this will determine the effect that will be had on their brain functioning, since, for some brain functions, interpreting the musical instrument increases and improves the performance of the cognitive process, and for other functions, it is to hear the music, and not to interpret the instrument, which favors a greater performance. Regardless of this, it was determined that there is an advantage in the results of brain function in those people who are exposed to this type of orchestral music, either as part of the orchestra or as a listener of the melody.

O objetivo desta pesquisa foi determinar as características funcionais do cérebro de intérpretes e ouvintes de música sinfônica. Para isso, foi desenvolvida uma pesquisa quantitativa de tipo comparativo-correlacional. 120 pessoas participaram e foram distribuídas em 3 grupos: intérpretes, ouvintes e controles; sendo iguais em idade, sexo e escolaridade. Os intérpretes apresentaram deficiência em fluência verbal semântica e dificuldades em planejamento de atividades, no entanto, têm maior desempenho em tarefas de memória visual, atenção e velocidade de processamento de informações, em comparação com aqueles que só ouvem a música e ainda mais com aqueles que não estão expostos a esse tipo de música. Por sua vez, os ouvintes apresentaram dificuldade em compreensão e melhor memória verbal, bem como uma organização do tipo executivo e fluência fonológica. Assim, a influência da música sinfónica sobre o funcionamento dos processos neurocognitivos varia e depende de como o indivíduo é exposto a ela, e isso vai determinar o efeito que terá sobre sua função cerebral, toda vez que, para algumas funções cerebrais interpretar os instrumentos musicais aumenta e melhora o desempenho do processamento cognitivo, e para outras funções, é ouvir a música, e não tocar o instrumento, o que favorece um melhor desempenho. Independentemente disso, determinou-se que há uma vantagem nos resultados da função cerebral naquelas pessoas que estão expostas a esse tipo de música orquestral, seja como parte da orquestra ou como ouvinte da melodia.

Changes of Cerebral Blood Volume During Robot-Assisted Laparoscopic Radical Prostatectomy: Observational Prospective Study Using Near-Infrared Time-Resolved Spectroscopy.

Purpose: Robot-assisted laparoscopic radical prostatectomy (RARP) requires a steep head-down tilt and pneumoperitoneum, which may cause an increase in cerebral blood volume (CBV). With a new near-infrared time-resolved spectroscopy device, the tNIRS-1, we can measure the absolute value of the cerebral hemoglobin concentration and hence calculate CBV and cerebral oxygen saturation (rSO2). Using this device, we evaluated the time course of CBV during surgery and also evaluated the changes in rSO2 simultaneously. Materials and Methods: We performed a prospective observational study of 21 patients scheduled for RARP. We evaluated CBV and rSO2 by using the tNIRS-1 at 10 time points during surgery. Results: The CBV was 2.92 ± 0.38 mL ·100 g-1 after the end of anesthetic preparation. It significantly increased to 3.05 ± 0.44 mL ·100 g-1 after the head-down tilt and was around 3.1 mL ·100 g-1 until 120 minutes after the head-down tilt. However, just before the return to the horizontal position, it decreased to 2.93 ± 0.46 mL ·100 g-1 and then decreased more after the return to the horizontal position. Changes in rSO2 over time were within only 3%, and no significant differences from the control value were observed. Conclusions: The increase in CBV was <10% despite the steep head-down tilt and pneumoperitoneum, and it was compensated for at around the end of surgery. Clinically significant changes in rSO2 were not observed during the surgery.

As consequências da restrição de crescimento intrauterino na estrutura e fluxo sanguíneo cerebral: uma revisão da literatura / The consequences of fetal growth restriction on brain structure and blood flow: a review

A Restrição de Crescimento Fetal (RCF) é definida como uma incapacidade do feto em alcançar seu potencial de crescimento, afeta 5-10% das gestações e está associada à alta morbimortalidade fetal e neonatal, principalmente a danos neurológicos. O objetivo dessa revisão foi levantar os estudos sobre a alteração cerebral nos fetos com RCF que possam estar relacionados aos danos neurológicos pós-natais já estabelecidos. Nesses fetos, há um crescimento desigual das estruturas cerebrais e reconhece-se que, na dependência de hipoxemia crônica e privação de nutrientes provocados pela insuficiência placentária, o feto tende a preferenciar o fluxo sanguíneo para o cérebro em detrimento de outros órgãos. Os resultados dessa revisão sugerem que o efeito protetor do aumento da perfusão sanguínea cerebral é diferente em cada estágio de deterioração fetal, propondo uma ordem hierárquica na proteção das diferentes funções/áreas cerebrais, e quanto mais severo esse acometimento, maiores mudanças estruturais cerebrais o feto apresentará.(AU)

Fetal growth restriction is defined as an inability of the fetus to reach its growth potential, affects 5-10% of pregnancies and is associated with high fetal and neonatal morbidity and mortality, mainly neurological damage. The aim of this review was to investigate brain alterations in fetus with fetal growth restriction that may be related to the already established postnatal neurological damage. In these fetus there is an uneven growth of the brain structures and it is recognized that in dependence on chronic hypoxemia and nutrient deprivation caused by placental insufficiency, the fetus tends to prefer the blood flow to the brain in detriment of other organs. The results of this review suggest that the protective effect of increased cerebral blood perfusion is different at each stage of fetal deterioration, proposing a hierarchical order in the protection of the different brain functions / areas and more severe this involvement, bigger structural changes the fetus will present.(AU)

A Connectomic Atlas of the Human Cerebrum-Chapter 1: Introduction, Methods, and Significance.

BACKGROUND: As knowledge of the brain has increased, clinicians have learned that the cerebrum is composed of complex networks that interact to execute key functions. While neurosurgeons can typically predict and preserve primary cortical function through the primary visual and motor cortices, preservation of higher cognitive functions that are less well localized in regions previously deemed "silent" has proven more difficult. This suggests these silent cortical regions are more anatomically complex and redundant than our previous methods of inquiry can explain, and that progress in cerebral surgery will be made with an improved understanding of brain connectomics. Newly published parcellated cortex maps provide one avenue to study such connectomics in greater detail, and they provide a superior framework and nomenclature for studying cerebral function and anatomy. OBJECTIVE: To describe the structural and functional aspects of the 180 distinct areas that comprise the human cortex model previously published under the Human Connectome Project (HCP). METHODS: We divided the cerebrum into 8 macroregions: lateral frontal, motor/premotor, medial frontal, insular, temporal, lateral parietal, medial parietal, and occipital. These regions were further subdivided into their relevant parcellations based on the HCP cortical scheme. Connectome Workbench was used to localize parcellations anatomically and to demonstrate their functional connectivity. DSI studio was used to assess the structural connectivity for each parcellation. RESULTS: The anatomy, functional connectivity, and structural connectivity of all 180 cortical parcellations identified in the HCP are compiled into a single atlas. Within each section of the atlas, we integrate this information, along with what is known about parcellation function to summarize the implications of these data on network connectivity. CONCLUSION: This multipart supplement aims to build on the work of the HCP. We present this information in the hope that the complexity of cerebral connectomics will be conveyed in a more manageable format that will allow neurosurgeons and neuroscientists to accurately communicate and formulate hypotheses regarding cerebral anatomy and connectivity. We believe access to this information may provide a foundation for improving surgical outcomes by preserving lesser-known networks.

Right Hemisphere Cognitive Functions: From Clinical and Anatomical Bases to Brain Mapping During Awake Craniotomy. Part II: Neuropsychological Tasks and Brain Mapping.

The nondominant hemisphere (usually right) is determinant for main cognitive functions such as visuospatial and social cognitions. Awake surgery using direct electrical stimulation for right cerebral tumor removal remains challenging due to the complexity of the functional anatomy and the difficulties in adapting the classical bedside tasks for awake surgery conditions. An understanding of semiology, anatomical bases, and an analysis of the available cognitive tasks for visuospatial and social cognition per operative mapping will allow neurosurgeons to better appreciate the functional anatomy of the right hemisphere and its application to tumor surgery. In this second review of 2 parts, we discuss the pertinence of the neuropsychological tests available for the study of nondominant hemisphere functions for the surgery on right-sided tumors in awake surgery conditions. In conjunction with part I of the review, which focuses primarily on the anatomical, functional, and semiological basis of the right hemisphere function, this article provides a comprehensive review of current knowledge supporting the awake surgery in the right hemisphere.

Right Hemisphere Cognitive Functions: From Clinical and Anatomic Bases to Brain Mapping During Awake Craniotomy Part I: Clinical and Functional Anatomy.

The nondominant hemisphere (usually the right) is responsible for primary cognitive functions such as visuospatial and social cognition. Awake surgery using direct electric stimulation for right cerebral tumor removal remains challenging because of the complexity of the functional anatomy and difficulties in adapting standard bedside tasks to awake surgery conditions. An understanding of semiology and anatomic bases, along with an analysis of the available cognitive tasks for visuospatial and social cognition per operative mapping allow neurosurgeons to better appreciate the functional anatomy of the right hemisphere and its relevance to tumor surgery. In this article, the first of a 2-part review, we discuss the anatomic and functional basis of right hemisphere function. Whereas part II of the review focuses primarily on semiology and surgical management of right-sided tumors under awake conditions, this article provides a comprehensive review of knowledge underpinning awake surgery on the right hemisphere.

[Effect of Stellate Ganglion Block on Bilateral Regional Cerebral Oxygen Saturation and Postoperative Cognitive Function].

The present study was to examine the effect of stellate ganglion block (SGB) on bilateral regional cerebral oxygen saturation (rSO2) and postoperative cognitive function. Eighty patients undergoing selective coronary artery bypass graft with cardiopulmonary bypass (CPB) were randomly and equally divided into two groups. The patients in group S were given right SGB with ropivacaine, while the patients in group C were injected with normal saline. We compared the bilateral rSO2 after SGB. Minimum Mental State Examination (MMSE), Visual Verbal Learning Test (VVLT), and Digital Span Test (DST) were applied to observe the effect on cognitive function. We found that the incidence of postoperative cognitive dysfunction (POCD) 7 days after surgery in group S was lower than that in group C. The level of blocked side rSO2 of S group were significantly higher before CPB time of rewarming than that before SGB (P < 0.05), much higher than corresponding non-blocked side rSO2 before CPB (P < 0.05), and much higher than rSO2 level in group C before CPB and after CPB (P < 0.05). The non-blocked side rSO2 in group S before anesthesia were much lower than basic levels and those in group C (P < 0.05). It could be concluded from the above results that there was significant increase in the blocked-side rSO2 compared to the non-blocked side and there was significant decrease in the incidence of POCD compared to the control group after SGB.

Single session imaging of cerebellum at 7 Tesla: obtaining structure and function of multiple motor subsystems in individual subjects.

The recent increase in the use of high field MR systems is accompanied by a demand for acquisition techniques and coil systems that can take advantage of increased power and accuracy without being susceptible to increased noise. Physical location and anatomical complexity of targeted regions must be considered when attempting to image deeper structures with small nuclei and/or complex cytoarchitechtonics (i.e. small microvasculature and deep nuclei), such as the brainstem and the cerebellum (Cb). Once these obstacles are overcome, the concomitant increase in signal strength at higher field strength should allow for faster acquisition of MR images. Here we show that it is technically feasible to quickly and accurately detect blood oxygen level dependent (BOLD) signal changes and obtain anatomical images of Cb at high spatial resolutions in individual subjects at 7 Tesla in a single one-hour session. Images were obtained using two high-density multi-element surface coils (32 channels in total) placed beneath the head at the level of Cb, two channel transmission, and three-dimensional sensitivity encoded (3D, SENSE) acquisitions to investigate sensorimotor activations in Cb. Two classic sensorimotor tasks were used to detect Cb activations. BOLD signal changes during motor activity resulted in concentrated clusters of activity within the Cb lobules associated with each task, observed consistently and independently in each subject: Oculomotor vermis (VI/VII) and CrusI/II for pro- and anti-saccades; ipsilateral hemispheres IV-VI for finger tapping; and topographical separation of eye- and hand- activations in hemispheres VI and VIIb/VIII. Though fast temporal resolution was not attempted here, these functional patches of highly specific BOLD signal changes may reflect small-scale shunting of blood in the microvasculature of Cb. The observed improvements in acquisition time and signal detection are ideal for individualized investigations such as differentiation of functional zones prior to surgery.

Measuring the effects of aging and sex on regional brain stiffness with MR elastography in healthy older adults.

Changes in tissue composition and cellular architecture have been associated with neurological disease, and these in turn can affect biomechanical properties. Natural biological factors such as aging and an individual's sex also affect underlying tissue biomechanics in different brain regions. Understanding the normal changes is necessary before determining the efficacy of stiffness imaging for neurological disease diagnosis and therapy monitoring. The objective of this study was to evaluate global and regional changes in brain stiffness as a function of age and sex, using improved MRE acquisition and processing that have been shown to provide median stiffness values that are typically reproducible to within 1% in global measurements and within 2% for regional measurements. Furthermore, this is the first study to report the effects of age and sex over the entire cerebrum volume and over the full frontal, occipital, parietal, temporal, deep gray matter/white matter (insula, deep gray nuclei and white matter tracts), and cerebellum volumes. In 45 volunteers, we observed a significant linear correlation between age and brain stiffness in the cerebrum (P<.0001), frontal lobes (P<.0001), occipital lobes (P=.0005), parietal lobes (P=.0002), and the temporal lobes (P<.0001) of the brain. No significant linear correlation between brain stiffness and age was observed in the cerebellum (P=.74), and the sensory-motor regions (P=.32) of the brain, and a weak linear trend was observed in the deep gray matter/white matter (P=.075). A multiple linear regression model predicted an annual decline of 0.011 ± 0.002 kPa in cerebrum stiffness with a theoretical median age value (76 years old) of 2.56 ± 0.08 kPa. Sexual dimorphism was observed in the temporal (P=.03) and occipital (P=.001) lobes of the brain, but no significant difference was observed in any of the other brain regions (P>.20 for all other regions). The model predicted female occipital and temporal lobes to be 0.23 kPa and 0.09 kPa stiffer than males of the same age, respectively. This study confirms that as the brain ages, there is softening; however, the changes are dependent on region. In addition, stiffness effects due to sex exist in the occipital and temporal lobes.

Effects of acute electromagnetic fields exposure on the interhemispheric homotopic functional connectivity during resting state.

In this paper, we aimed to investigate the possible effects of acute radiofrequency electromagnetic fields (EMF) on the interhemispheric homotopic functional connectivity with resting state functional magnetic resonance imaging (fMRI) technique. We designed a controllable LTE-related EMF exposure environment at 2.573 GHz and performed the 30 min real/sham exposure experiments on human brain under the safety limits. The resting state fMRI signals were collected before and after EMF exposure. Then voxel-mirrored homotopic connectivity method was utilized to evaluate the acute effects of LTE EMF exposure on the homotopic functional connectivity between two human hemispheres. Based on our previous research, we further demonstrated that the 30 min short-term LTE EMF exposure would modulate the interhemispheric homotopic functional connectivity in resting state around the medial frontal gyrus and the paracentral lobule during the real exposure.

Adaptations of energy metabolism during cerebellar neurogenesis are co-opted in medulloblastoma.

Recent studies show that metabolic patterns typical of cancer cells, including aerobic glycolysis and increased lipogenesis, are not unique to malignancy, but rather originate in physiologic development. In the postnatal brain, where sufficient oxygen for energy metabolism is scrupulously maintained, neural progenitors nevertheless metabolize glucose to lactate and prioritize lipid synthesis over fatty acid oxidation. Medulloblastoma, a cancer of neural progenitors that is the most common malignant brain tumor in children, recapitulates the metabolic phenotype of brain progenitor cells. During the physiologic proliferation of neural progenitors, metabolic enzymes generally associated with malignancy, including Hexokinase 2 (Hk2) and Pyruvate kinase M2 (PkM2) configure energy metabolism to support growth. In these non-malignant cells, expression of Hk2 and PkM2 is driven by transcriptional regulators that are typically identified as oncogenes, including N-myc. Importantly, N-myc continues to drive Hk2 and PkM2 in medulloblastoma. Similarly E2F transcription factors and PPARγ function in both progenitors and medulloblastoma to optimize energy metabolism to support proliferation. These findings show that the "metabolic transformation" that is a hallmark of cancer is not specifically limited to cancer. Rather, metabolic transformation represents a co-opting of developmental programs integral to physiologic growth. Despite their physiologic origins, the molecular mechanisms that mediate metabolic transformation may nevertheless present ideal targets for novel anti-tumor therapy.