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Functional connectivity between cortical areas may appear as correlated time behavior of neural activity. It has been suggested that merging of separate features into a single percept ("binding") is associated with coherent gamma band activity across the cortical areas involved. Therefore, it would be of utmost interest to image cortico-cortical coherence(More)
Magnetoencephalographic (MEG) and electromyographic (EMG) signals were recorded from six subjects during isometric contraction of four different muscles. Cortical sources were located from the MEG signal which was averaged time-locked to the onset of motor unit potentials. A spatial filtering algorithm was used to estimate the source activity. Sources were(More)
The basic question of whether the human brain controls continuous movements intermittently is still under debate. Here we show that 6- to 9-Hz pulsatile velocity changes of slow finger movements are directly correlated to oscillatory activity in the motor cortex, which is sustained by cerebellar drive through thalamus and premotor cortex. Our findings(More)
The neural mechanisms subserving uni- and bimanual control of movements are not well understood. Nevertheless, recent studies indicate a functional role of oscillatory activity in movement control and point towards a hemispheric asymmetry in motor control. This study specifically addresses the issues of (i) task-relatedness, (ii) hemispheric symmetry, and(More)
ing from this point of view, one could say that we have built and tested a crude membrane model in which such a phenomenon might be observed, and that thus far the binding energies agree satisfactorily with those calculated from in vivo experiments only when the model contains lipid. In so far as we understand the behavior of the model, it does not permit(More)
We have investigated the long-term effects of 15-16 min or 19-20 min of perinatal asphyxia on D1, D2, and D3 receptors (analyzed by quantitative autoradiography) in the mesotelencephalic dopamine systems of the 4-week-old rat. Perinatal asphyxia reduced D1 antagonist binding ([3H]SCH 23390 in the presence of ketanserine) in the accumbens nucleus, the(More)
Perinatal asphyxia (15-22 min) was induced to male Sprague-Dawley rat pups during the last day of gestation and the surviving pups were sacrificed at 4 weeks of age. Brain sections were stained for tyrosine hydroxylase immunoreactivity and Cresyl violet. With increasing duration of perinatal asphyxia a reduction in the number of tyrosine hydroxylase(More)
Oxidative damage accumulation in macromolecules has been considered as a cause of cellular damage and pathology. Rarely, the oxidative stress parameters in healthy humans related to the individual age have been reported. The purpose of this study was to examine the redox status in plasma and erythrocytes of healthy individuals and determine correlations(More)
The authors investigated 12 patients with cirrhosis who had hepatic encephalopathy (HE): six with continuous mini-asterixis and six with subclinical HE without asterixis. They studied the coupling between hand-muscle electromyography (EMG) recordings and brain activity recorded by magnetoencephalography. On forearm elevation, patients with tremor developed(More)
Recently, it was shown that a slowed motor cortical drive in hepatic encephalopathy (HE) results in mini-asterixis (MA). During forearm elevation, the authors have now investigated the coupling between motor cortex and thalamic activity using magnetoencephalography in six cirrhotic patients with HE and MA and in six control subjects. HE patients showed(More)