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Plasticity in the brain reaches far beyond a mere changing of synaptic strengths. Recent time-lapse imaging in the living brain reveals ongoing structural plasticity by forming or breaking of synapses, motile spines, and re-routing of axonal branches in the developing and adult brain. Some forms of structural plasticity do not follow Hebbian- or(More)
Despite the fact that essential tremor (ET) is the most prevalent movement disorder, the underlying pathological mechanisms are not fully understood. There is accumulating evidence that this specific type of tremor is mainly of central origin, in particular involving inferior olive, cerebellum, thalamus, and primary motor cortex. We studied 8 patients with(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)
Neuronal oscillations are assumed to play a pivotal role in the pathophysiology of Parkinson's disease (PD). Neurons in the subthalamic nucleus (STN) generate oscillations which are coupled to rhythmic population activity both in other basal ganglia nuclei and cortical areas. In order to localize these cortical areas, we recorded local field potentials(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)
We describe a strongly biologically motivated artificial neural network approach to model neurogenesis and synaptic turnover as it naturally occurs for example in the hippocampal dentate gyrus (DG) of the developing and adult mammalian and human brain. The results suggest that cell proliferation (CP) has not only a functional meaning for computational tasks(More)
Increasing evidence suggests that abnormal oscillatory activity in basal ganglia and cortex plays a pivotal role in the pathophysiology of Parkinson's disease. Recordings of local field potentials from subthalamic nucleus of patients undergoing deep brain stimulation have focused on oscillations occurring at frequencies below 100 Hz in the alpha, beta and(More)
Recently evidence has accumulated that many neural networks exhibit self-organized criticality. In this state, activity is similar across temporal scales and this is beneficial with respect to information flow. If subcritical, activity can die out, if supercritical epileptiform patterns may occur. Little is known about how developing networks will reach and(More)
Lasting alterations in sensory input trigger massive structural and functional adaptations in cortical networks. The principles governing these experience-dependent changes are, however, poorly understood. Here, we examine whether a simple rule based on the neurons' need for homeostasis in electrical activity may serve as driving force for cortical(More)
OBJECTIVE Hepatic encephalopathy (HE) is characterized by neuropsychological and motor deficits. The present study tested the hypothesis that worsening of motor and sensory symptoms of HE results from a common basic deficit in the cerebral oscillatory processing within the human motor and visual system. METHODS We investigated in 32 patients with liver(More)