scholarly journals The Detailed Organization of the Human Cerebellum Estimated by Intrinsic Functional Connectivity Within the Individual

Author(s):  
Aihuiping Xue ◽  
Ru Kong ◽  
Qing Yang ◽  
Mark C. Eldaief ◽  
Peter Angeli ◽  
...  

Distinct regions of the cerebellum connect to separate regions of the cerebral cortex forming a complex topography. While cerebellar organization has been examined in group-averaged data, study of individuals provides an opportunity to discover features that emerge at a higher spatial resolution. Here functional connectivity MRI was used to examine the cerebellum of two intensively-sampled individuals (each scanned 31 times). Connectivity to somatomotor cortex showed the expected crossed laterality and topography of the body maps. A surprising discovery was connectivity to the primary visual cortex along the vermis with evidence for representation of the central field. Within the hemispheres, each individual displayed a hierarchical progression from the inverted anterior lobe somatomotor map through to higher-order association zones. The hierarchy ended at Crus I/II and then progressed in reverse order through to the upright somatomotor map in the posterior lobe. Evidence for a third set of networks was found in the most posterior extent of the cerebellum. Detailed analysis of the higher-order association networks revealed robust representations of two distinct networks linked to the default network, multiple networks linked to cognitive control, as well as a separate representation of a language network. While idiosyncratic spatial details emerged between subjects, each network could be detected in both individuals, and seed regions placed within the cerebellum recapitulated the full extent of the spatially-specific cerebral networks. The observation of multiple networks in juxtaposed regions at the Crus I/II apex confirms the importance of this zone to higher-order cognitive function and reveals new organizational details.

Author(s):  
Aihuiping Xue ◽  
Ru Kong ◽  
Qing Yang ◽  
Mark C. Eldaief ◽  
Peter Angeli ◽  
...  

Distinct regions of the cerebellum connect to separate regions of the cerebral cortex forming a complex topography. While key properties of cerebellar organization have been revealed in group-averaged data, in-depth study of individuals provides an opportunity to discover functional-anatomical features that emerge at a higher spatial resolution. Here functional connectivity MRI was used to examine the cerebellum of two intensively-sampled individuals (each scanned across 31 MRI sessions). Connectivity to somatomotor cortex showed the expected crossed laterality and inversion of the body maps between the anterior and posterior lobes. A surprising discovery was connectivity to the primary visual cortex along the vermis with evidence for representation of the central field. Within the hemispheres, each individual displayed a hierarchical progression from the inverted anterior lobe somatomotor map through to higher-order association zones. The hierarchy ended near Crus I/II and then progressed in reverse order through to the upright somatomotor map in the posterior lobe. Evidence for a third set of networks was found in the most posterior extent of the cerebellum. Detailed analysis of the higher-order association networks around the Crus I/II apex revealed robust representations of two distinct networks linked to the default network, multiple networks linked to cognitive control, as well as a separate representation of a language network. While idiosyncratic spatial details emerged between subjects, each of these networks could be detected in both individuals, and small seed regions placed within the cerebellum recapitulated the full extent of the spatially-specific cerebral networks. The observation of multiple networks in juxtaposed regions at the Crus I/II apex confirms the importance of this zone to higher-order cognitive function and reveals new organizational details.


2011 ◽  
Vol 106 (5) ◽  
pp. 2322-2345 ◽  
Author(s):  
Randy L. Buckner ◽  
Fenna M. Krienen ◽  
Angela Castellanos ◽  
Julio C. Diaz ◽  
B. T. Thomas Yeo

The cerebral cortex communicates with the cerebellum via polysynaptic circuits. Separate regions of the cerebellum are connected to distinct cerebral areas, forming a complex topography. In this study we explored the organization of cerebrocerebellar circuits in the human using resting-state functional connectivity MRI (fcMRI). Data from 1,000 subjects were registered using nonlinear deformation of the cerebellum in combination with surface-based alignment of the cerebral cortex. The foot, hand, and tongue representations were localized in subjects performing movements. fcMRI maps derived from seed regions placed in different parts of the motor body representation yielded the expected inverted map of somatomotor topography in the anterior lobe and the upright map in the posterior lobe. Next, we mapped the complete topography of the cerebellum by estimating the principal cerebral target for each point in the cerebellum in a discovery sample of 500 subjects and replicated the topography in 500 independent subjects. The majority of the human cerebellum maps to association areas. Quantitative analysis of 17 distinct cerebral networks revealed that the extent of the cerebellum dedicated to each network is proportional to the network's extent in the cerebrum with a few exceptions, including primary visual cortex, which is not represented in the cerebellum. Like somatomotor representations, cerebellar regions linked to association cortex have separate anterior and posterior representations that are oriented as mirror images of one another. The orderly topography of the representations suggests that the cerebellum possesses at least two large, homotopic maps of the full cerebrum and possibly a smaller third map.


2010 ◽  
Vol 23 (1-2) ◽  
pp. 65-79 ◽  
Author(s):  
Catherine J. Stoodley ◽  
Eve M. Valera ◽  
Jeremy D. Schmahmann

Neuroimaging studies report cerebellar activation during both motor and non-motor paradigms, and suggest a functional topography within the cerebellum. Sensorimotor tasks activate the anterior lobe, parts of lobule VI, and lobule VIII, whereas higher-level tasks activate lobules VI and VII in the posterior lobe. To determine whether these activation patterns are evident at a single-subject level, we conducted functional magnetic resonance imaging (fMRI) during five tasks investigating sensorimotor (finger tapping), language (verb generation), spatial (mental rotation), working memory (N-back), and emotional processing (viewing images from the International Affective Picture System). Finger tapping activated the ipsilateral anterior lobe (lobules IV-V) as well as lobules VI and VIII. Activation during verb generation was found in right lobules VII and VIIIA. Mental rotation activated left-lateralized clusters in lobules VII-VIIIA, VI-Crus I, and midline VIIAt. The N-back task showed bilateral activation in right lobules VI-Crus I and left lobules VIIB-VIIIA. Cerebellar activation was evident bilaterally in lobule VI while viewing arousing vs. neutral images. This fMRI study provides the first proof of principle demonstration that there is topographic organization of motor execution vs. cognitive/emotional domains within the cerebellum of a single individual, likely reflecting the anatomical specificity of cerebro-cerebellar circuits underlying different task domains. Inter-subject variability of motor and non-motor topography remains to be determined.


2003 ◽  
Vol 90 (3) ◽  
pp. 1877-1886 ◽  
Author(s):  
A. Dimitrova ◽  
F. P. Kolb ◽  
H.-G. Elles ◽  
M. Maschke ◽  
M. Forsting ◽  
...  

The aim of the present study was to examine nociceptive leg withdrawal reflex–related areas in the human cerebellum using event-related functional brain imaging (fMRI). Knowledge about cerebellar areas involved in unconditioned limb withdrawal reflex control has some relevance in understanding data of limb withdrawal reflex conditioning studies. Sixteen healthy adult subjects participated. Nociceptive leg withdrawal reflexes were evoked by electrical stimulation of the left tibial nerve behind the medial malleolus. An event-related fMRI paradigm was applied with a total of 30 stimuli being delivered pseudorandomly during 500 consecutive MR scans. Surface electromyographic (EMG) recordings were performed from the left anterior tibial muscle. Only trials with significant reflex EMG activity were used as active events in fMRI statistical analysis. The specified contrasts compared the active event condition with rest. Leg withdrawal reflex–related areas were located within the vermis, paravermis, and lateral posterior cerebellar hemispheres bilaterally. Vermal and paravermal areas in lobules III/IV in the anterior lobe and in lobule VIII in the posterior lobe agree with the cerebellar representation of climbing and mossy fiber hindlimb afferents and voluntary leg movements. They are likely related to efferent modulation of the leg withdrawal reflex and/or sensory processing of afferent inputs from the reflex and/or the noxious stimulus. Additional activation within vermal lobule VI and hemispheral lobules VI/Crus I may be related to other pain-related processes (e.g., facial grimacing, fear, and startlelike reactions).


1975 ◽  
Vol 66 (1) ◽  
pp. 85-91 ◽  
Author(s):  
A. CYRKOWICZ ◽  
W. Z. TRACZYK

SUMMARY The posterior pituitary lobe of male rats under urethane anaesthesia was incubated in situ. The pituitary gland was exposed by the transpharyngeal approach. The posterior lobe remained in neural and partial vascular connexion with the hypothalamus, whereas the anterior lobe was entirely removed. Incubation fluid was collected and its melanophore-stimulating activity was assayed in hypophysectomized frogs. No effect was observed after the i.v. injection of 1 ml 120 μm-NaCl with 60 μm-CaCl2 or isotonic NaCl solution. Hypertonic solutions of 5% NaCl and 25% glucose injected intravenously to the limit of 0·5% of the body weight, transiently enhanced the release of MSH from the posterior pituitary lobe by 66% (significant) and 15% (not significant) respectively. Intracarotid injection of 0·3 ml 5% NaCl solution resulted in the highest increase (95%) of MSH release.


2013 ◽  
Vol 109 (1) ◽  
pp. 46-57 ◽  
Author(s):  
Danhong Wang ◽  
Randy L. Buckner ◽  
Hesheng Liu

Asymmetry of the human cerebellum was investigated using intrinsic functional connectivity. Regions of functional asymmetry within the cerebellum were identified during resting-state functional MRI ( n = 500 subjects) and replicated in an independent cohort ( n = 500 subjects). The most strongly right lateralized cerebellar regions fell within the posterior lobe, including crus I and crus II, in regions estimated to link to the cerebral association cortex. The most strongly left lateralized cerebellar regions were located in lobules VI and VIII in regions linked to distinct cerebral association networks. Comparison of cerebellar asymmetry with independently estimated cerebral asymmetry revealed that the lateralized regions of the cerebellum belong to the same networks that are strongly lateralized in the cerebrum. The degree of functional asymmetry of the cerebellum across individuals was significantly correlated with cerebral asymmetry and varied with handedness. In addition, cerebellar asymmetry estimated at rest predicted cerebral lateralization during an active language task. These results demonstrate that functional lateralization is likely a unitary feature of large-scale cerebrocerebellar networks, consistent with the hypothesis that the cerebellum possesses a roughly homotopic map of the cerebral cortex including the prominent asymmetries of the association cortex.


2001 ◽  
Vol 40 (01) ◽  
pp. 31-37 ◽  
Author(s):  
U. Wellner ◽  
E. Voth ◽  
H. Schicha ◽  
K. Weber

Summary Aim: The influence of physiological and pharmacological amounts of iodine on the uptake of radioiodine in the thyroid was examined in a 4-compartment model. This model allows equations to be derived describing the distribution of tracer iodine as a function of time. The aim of the study was to compare the predictions of the model with experimental data. Methods: Five euthyroid persons received stable iodine (200 μg, 10 mg). 1-123-uptake into the thyroid was measured with the Nal (Tl)-detector of a body counter under physiological conditions and after application of each dose of additional iodine. Actual measurements and predicted values were compared, taking into account the individual iodine supply as estimated from the thyroid uptake under physiological conditions and data from the literature. Results: Thyroid iodine uptake decreased from 80% under physiological conditions to 50% in individuals with very low iodine supply (15 μg/d) (n = 2). The uptake calculated from the model was 36%. Iodine uptake into the thyroid did not decrease in individuals with typical iodine supply, i.e. for Cologne 65-85 μg/d (n = 3). After application of 10 mg of stable iodine, uptake into the thyroid decreased in all individuals to about 5%, in accordance with the model calculations. Conclusion: Comparison of theoretical predictions with the measured values demonstrated that the model tested is well suited for describing the time course of iodine distribution and uptake within the body. It can now be used to study aspects of iodine metabolism relevant to the pharmacological administration of iodine which cannot be investigated experimentally in humans for ethical and technical reasons.


2020 ◽  
Vol 11 (SPL1) ◽  
pp. 1477-1481
Author(s):  
Ishwari Gaikwad ◽  
Priyanka Shelotkar

The current world situation is both frightening and alarming due to the massive disruption caused by the Covid-19 pandemic. The next few days are censorious as we need to be very precautious in our daily regimen as well as dietary habits. Ayurveda offers knowledge about food based on certain reasoning. Indecent food custom is the chief cause for the rising development of health disorders in the current era. In classical texts of Ayurveda, the concept of diet explained well, ranging from their natural sources, properties and specific utility in pathological as well as physiological manner. In this work, the review of the relevant literature of Ahara (Diet) was carried out from Charak Samhita and other texts, newspapers, articles, web page related to the same.  Every human being is unique with respect to his Prakriti (Physical and mental temperament), Agni (Digestive capacity), Koshtha  (Nature of bowel) etc. For that reason, the specificity of the individual should be kept in mind. Ahara, when consumed in the appropriate amount at the right moment following all Niyamas (Guidelines) given in Ayurveda texts, gives immunity and keeps the body in a healthy state during pandemics such as Covid-19. Ultimately, this will help the human body to maintain its strength for life. This article reviews the concept of diet viz. combination of foods, their quantity and quality, methods of preparation and processing, which are to be followed during pandemics and are essential in maintenance and endorsement of health and preclusion of diseases.


2020 ◽  
Vol 5 (5) ◽  
pp. 386-393
Author(s):  
L. M. Gunina ◽  
◽  
Kazys Mylashyus ◽  
Voitenko V. L. ◽  
◽  
...  

Under high-intensity loads, the athlete's bodies take place a number of biochemical reactions and physiological processes that can lead to hyperbilirubinemia. The factors that can initiate the onset of this phenomenon include the syndrome of micro-damage muscle, violation of the integrity of erythrocyte membranes, decreased blood pH, malnutrition and increase oxygen demand of the body. Degree of expression of manifestations of physiological bilirubinemia depends on the level of adaptation of the athlete to the physical activities offered. Hyperbilirubinemia in athletes can be one of the components of the deterioration of the functional state, forming the symptoms of endogenous intoxication. The relevance of this problem in sport lies in the relatively low detection rate of hyperbilirubinemia due to the lack of regular screening studies. However, in drawing up a plan of nutritional- metabolic support for training and competitive activity and recovery measures, must not only the individual reaction of the athlete body to physical activity, but also the severity of shifts in the indicators of bilirubin metabolism and their ratio. The article describes the reasons for the increase in bilirubin levels, which can be caused by both the effect of physical activity and by the presence of pathological processes in athletes. The factors influencing the blood serum’s bilirubin content are also highlighted, which include the state of erythrocyte cell membranes and the rate of hemoglobin destruction, the functional state of the liver, the specifics of physical loads and the use of ergogenic pharmacological agents by athletes. Particular accent has been placed on the illumination of hereditary hyperbilirubinemias, which may have been detected at the stage of selection of athletes. The most common phenomenon is Gilbert's syndrome, which occurs in 2-5% of cases in the general population, is characterized in the clinic by a benign flow and is manifested by episodes of jaundice and an increase in total bilirubin content to moderate values due to indirect. The frequency of detection of hyperbilirubinemias in the population of athletes is 4.68%, among which Gilbert's disease accounts for almost half (48.7%). Conclusion. The work highlighted the pathogenesis and diagnostic algorithm of Gilbert's disease, and also emphasized that its drug prevention and correction in athletes to maintain functional and physical fitness should be carried out taking into account anti-doping rules, which requires upon diagnosis timely receipt of a therapeutic exclusion


2020 ◽  
Author(s):  
Maksim Rudnev

A theory of basic human values relies on the similarity of value structures across countries. It has been well established that the quasi-circumplex value structure as a whole is indeed universal. However, less attention has been paid to the associations between specific values. This study investigated associations between four higher-order values across age, education, and income groups. We analyzed the data from national representative samples collected in 29 countries as part of the fourth round of the European Social Survey with a series of multilevel regressions. Younger age, higher levels of education and income coincided with higher independence of the four adjacent higher-order values, whereas among older, less educated, and less wealthy groups, values tended to merge into a single dimension of Social versus Person Focus. These differences were slightly weaker in more economically developed countries. The group differences in value associations may follow from corresponding differences in the degree of societal and individual empowerment, cognitive abilities, and socialization experiences. Accounting for the individual differences in relations between values may bring deeper understanding and higher predictive power to the studies of links between values and various behaviors or attitudes. , value structure, value interactions, European Social Survey


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