2,479 research outputs found

    Neuroimaging evidence implicating cerebellum in support of sensory/cognitive processes associated with thirst.

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    Recent studies implicate the cerebellum, long considered strictly a motor control structure, in cognitive, sensory, and affective phenomenon. The cerebellum, a phylogenetically ancient structure, has reciprocal ancient connections to the hypothalamus, a structure important in vegetative functions. The present study investigated whether the cerebellum was involved in vegetative functions and the primal emotions engendered by them. Using positron emission tomography, we examined the effects on the cerebellum of the rise of plasma sodium concentration and the emergence of thirst in 10 healthy adults. The correlation of regional cerebral blood flow with subjects' ratings of thirst showed major activation in the vermal central lobule. During the development of thirst, the anterior and posterior quadrangular lobule, lingula, and the vermis were activated. At maximum thirst and then during irrigation of the mouth with water to alleviate dryness, the cerebellum was less activated. However, 3 min after drinking to satiation, the anterior quadrangular lobule and posterior cerebellum were highly activated. The increased cerebellar activity was not related to motor behavior as this did not occur. Instead, responses in ancient cerebellar regions (vermis, fastigal nucleus, archicerebellum) may be more directly related to vegetative and affective aspects of thirst experiences, whereas activity in neocerebellar (posterior) regions may be related to sensory and cognitive aspects. Moreover, the cerebellum is apparently not involved in the computation of thirst per se but rather is activated during changes in thirst/satiation state when the brain is "vigilant" and is monitoring its sensory systems. Some neocerebellar activity may also reflect an intentionality for gratification by drinking inherent in the consciousness of thirst

    Segregated Fronto-Cerebellar Circuits Revealed by Intrinsic Functional Connectivity

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    Multiple, segregated fronto-cerebellar circuits have been characterized in nonhuman primates using transneuronal tracing techniques including those that target prefrontal areas. Here, we used functional connectivity MRI (fcMRI) in humans (n = 40) to identify 4 topographically distinct fronto-cerebellar circuits that target 1) motor cortex, 2) dorsolateral prefrontal cortex, 3) medial prefrontal cortex, and 4) anterior prefrontal cortex. All 4 circuits were replicated and dissociated in an independent data set (n = 40). Direct comparison of right- and left-seeded frontal regions revealed contralateral lateralization in the cerebellum for each of the segregated circuits. The presence of circuits that involve prefrontal regions confirms that the cerebellum participates in networks important to cognition including a specific fronto-cerebellar circuit that interacts with the default network. Overall, the extent of the cerebellum associated with prefrontal cortex included a large portion of the posterior hemispheres consistent with a prominent role of the cerebellum in nonmotor functions. We conclude by providing a provisional map of the topography of the cerebellum based on functional correlations with the frontal cortex

    The Case Against Animal Rights

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    With a Broad Brush: The Federal Regulation of Sanctions against Burma (Myanmar)

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    On April 21, 1998, the Office of Foreign Assets Control of the U.S. Treasury Department issued regulations to implement the Executive Order that applied sanctions against Myanmar. With certain exceptions, the Regulations prohibit new investment by U.S. individuals or companies in Myanmar. This Essay explains and analyzes the reach of the Regulations and their potential ramifications

    Evidence of cerebellar involvement in the onset of a manic state

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    We described the cerebello-cerebral functional connectivity in a subject who developed a manic state after a cerebellar lesion. Whole brain investigation, performed by means of an advanced MRI examination, evidenced an isolated lesion involving the left lobules VI, VIIa (crus I), and IX and the posterior area of the vermis. The cerebello-cerebral functional connectivity analysis detected a pattern of altered connectivity in specific areas of the prefrontal-striatal-thalamic circuits that are typically altered in bipolar subjects during the manic state. Specifically, a pattern of hypo-connectivity was found between the cerebellum and cerebral regions known to be implicated in emotion modulation and social interaction. Conversely, a pattern of hyper-connectivity was found between the cerebellum and posterior cerebral cortical regions that are involved in sensorimotor functions. The present study represents the first evidence that dysregulation of cerebral networks consequent to a cerebellar lesion is at the root of bipolar disorder, at least the manic state, and provides a new framework for interpreting cerebellar modulation in the regulation of mood in specific psychiatric conditions

    Manic Episode Associated with Mega Cisterna Magna

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    Mega cisterna magna is a part of "Dandy-Walker Complex" and it is characterized by the enlargement of the cisterna magna, morphologically intact vermis and cerebellar hemispheres. We report a case of manic attack in a 23-year-old man with mega cisterna magna. The patient was treated with quetiapine 1,000 mg/day and sodium valproate 1,500 mg/day and the symptoms were ameliorated within 2.5 months. In this case, mega cisterna magna and manic symptoms may be found together coincidentally or any cerebellar dysfunction due to mega cisterna magna may cause or contribute to the appearance of affective symptoms. To our knowledge, this is the first case reporting manic attack with psychotic symptoms associated with mega cisterna magna. This report suggests that any lesion in the cerebellum might contribute to the occurrences of some affective and psychotic symptoms seen in bipolar disorder

    Akinetic Mutism and Cognitive-Affective Syndrome Caused by Unilateral PICA Infarction

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    A 42-year-old man with left posterior inferior cerebellar artery (PICA) infarction presented with akinetic mutism and cognitive impairment. Initially he suffered from akinetic mutism and MRI-documented infarction in the distribution of the left PICA. Twelve days later he developed cognitive impairment. Neuropsychological tests were performed, with the results corrected for age and education being compared with published Korean norms. Impaired performances were evident on executive function testing, with difficulties in planning, abstract reasoning, set-shifting, and perseveration. Akinetic mutism and cognitive-affective syndrome may be a manifestation of unilateral PICA infarction

    Abnormal synchrony and effective connectivity in patients with schizophrenia and auditory hallucinations

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    [EN] Auditory hallucinations (AH) are the most frequent positive symptoms in patients with schizophrenia. Hallucinations have been related to emotional processing disturbances, altered functional connectivity and effective connectivity deficits. Previously, we observed that, compared to healthy controls, the limbic network responses of patients with auditory hallucinations differed when the subjects were listening to emotionally charged words. We aimed to compare the synchrony patterns and effective connectivity of task-related networks between schizophrenia patients with and without AH and healthy controls. Schizophrenia patients with AH (n = 27) and without AH (n = 14) were compared with healthy participants (n = 31). We examined functional connectivity by analyzing correlations and cross-correlations among previously detected independent component analysis time courses. Granger causality was used to infer the information flow direction in the brain regions. The results demonstrate that the patterns of cortico-cortical functional synchrony differentiated the patients with AH from the patients without AH and from the healthy participants. Additionally, Granger-causal relationships between the networks clearly differentiated the groups. In the patients with AH, the principal causal source was an occipital¿cerebellar component, versus a temporal component in the patients without AH and the healthy controls. These data indicate that an anomalous process of neural connectivity exists when patients with AH process emotional auditory stimuli. Additionally, a central role is suggested for the cerebellum in processing emotional stimuli in patients with persistent AH.Funding for this study was provided by Spanish grants from Ministry of Science and Innovation (ISCIII: FIS P.I.02/0018, P.I.05/2332.), Spanish Mental Health Network: CIBERSAM and Combiomed Network.De La Iglesia-Vaya, M.; Escartí Fabra, MJ.; Molina-Mateo, J.; Marti-Bonmati, L.; Gadea, M.; Castellanos, FX.; Aguilar Garcia-Iturrospe, EJ.... (2014). Abnormal synchrony and effective connectivity in patients with schizophrenia and auditory hallucinations. NeuroImage Clinical. 6:171-179. https://doi.org/10.1016/j.nicl.2014.08.027S171179

    Defining a sphere of influence: Karel Landman’s centenary monument

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    History and International Relation

    Development of a psychiatric disorder linked to cerebellar lesions

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    Cerebellar dysfunction plays a critical role in neurodevelopmental disorders with long-term behavioral and neuropsychiatric symptoms. A 43-year-old woman with a cerebellum arteriovenous malformation and history of behavioral dysregulation since childhood is described. After the rupture of the cerebellar malformation in adulthood, her behavior morphed into specific psychiatric symptoms and cognitive deficits occurred. The neuropsychological assessment evidenced impaired performance in attention, visuospatial, memory, and language domains. Moreover, psychiatric assessment indicated a borderline personality disorder. Brain MRI examination detected macroscopic abnormalities in the cerebellar posterior lobules VI, VIIa (Crus I), and IX, and in the posterior area of the vermis, regions usually involved in cognitive and emotional processing. The described patient suffered from cognitive and behavioral symptoms that are part of the cerebellar cognitive affective syndrome. This case supports the hypothesis of a cerebellar role in personality disorders emphasizing the importance of also examining the cerebellum in the presence of behavioral disturbances in children and adults
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