U Büttner

Ludwig-Maximilian-University of Munich, München, Bavaria, Germany

Are you U Büttner?

Claim your profile

Publications (140)441.02 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Lesion studies argue for an involvement of cortical area dorsal medial superior temporal area (MSTd) in the control of optokinetic response (OKR) eye movements to planar visual stimulation. Neural recordings during OKR suggested that MSTd neurons directly encode stimulus velocity. On the other hand, studies using radial visual flow together with voluntary smooth pursuit eye movements showed that visual motion responses were modulated by eye movement-related signals. Here, we investigated neural responses in MSTd during continuous optokinetic stimulation using an information-theoretic approach for characterizing neural tuning with high resolution. We show that the majority of MSTd neurons exhibit gain-field-like tuning functions rather than directly encoding one variable. Neural responses showed a large diversity of tuning to combinations of retinal and extraretinal input. Eye velocity-related activity was observed prior to the actual eye movements, reflecting an efference copy. The observed tuning functions resembled those emerging in a network model trained to perform summation of 2 population-coded signals. Together, our findings support the hypothesis that MSTd implements the visuomotor transformation from retinal to head-centered stimulus velocity signals for the control of OKR.
    Cerebral Cortex 02/2014; · 8.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Human head movement can be looked at, as a rotational dynamics on the space SO(3) with constraints that have to do with the axis of rotation. Typically the axis vector, after a suitable scaling, is assumed to lie in a surface called Donders’ surface. Various descriptions of Donders’ surface are in the literature and in this paper we assume that the surface is described by a quadratic form. We propose a Tait–Bryan parametrization of SO(3), that is new in the head movement literature, and describe Donders’ constraint in these parameters. Assuming that the head is a perfect sphere with its mass distributed uniformly and rotating about its own center, head movement models are constructed using classical mechanics. A new potential control method is described to regulate the head to a desired final orientation. Optimal head movement trajectories are constructed using a pseudospectral method, where the goal is to minimize a quadratic cost function on the energy of the applied control torques. The model trajectories are compared with measured trajectories of human head movement.
    Automatica. 01/2014;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cerebellar dysfunction results in ataxia including postural deficits. Evidence from animal experiments suggests convergence of vestibular and neck-position related inputs in cerebellar midline structures. We investigated 20 ambulatory patients with cerebellar disease for disturbed postural control using posturography during static lateral head turns. Binaural bipolar sine-wave galvanic vestibular stimulation (GVS) was used to evoke specific body movements. The Klockgether clinical score was used to assess the severity of cerebellar dysfunction (4-17 of maximal 35 points). In 12 healthy controls and seven lightly affected patients (score <8), GVS elicited physiologic alternating body sway in the head-frontal plane in seven head-on-trunk positions (0°; 30°, 45° and 60° left and right). Body sway turning with head excursion was progressively attenuated or abolished in more severely affected patients (scores 9-17; r = 0.57, p = 0.008). With most severe impairment, body sway was always in the body-frontal plane irrespective of head turn. A simple clinical test with walking under maximal head turn and closed eyes correlated with posturography data (r = 0.87, p < 0.001) and with Klockgether scores (r = 0.71, p < 0.001). Thus in cerebellar disease, head on trunk position can have a pronounced effect on postural control.
    Journal of Neurology 10/2012; · 3.58 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Neurons in macaque cortical area MSTd are driven by visual motion and eye movement related signals. This multimodal characteristic makes MSTd an ideal system for studying the dependence of neuronal activity on different variables. Here, we analyzed the temporal structure of spiking patterns during visual motion stimulation using 2 distinct behavioral paradigms: fixation (FIX) and optokinetic response. For the FIX condition, inter- and intra-trial variability of spiking activity decreased with increasing stimulus strength, complying with a recent neurophysiological study reporting stimulus-related decline of neuronal variability. In contrast, for the optokinetic condition variability increased together with increasing eye velocity while retinal image velocity remained low. Analysis of stimulus signal variability revealed a correlation between the normalized variance of image velocity and neuronal variability, but no correlation with normalized eye velocity variance. We further show that the observed difference in neuronal variability allows classifying spike trains according to the paradigm used, even when mean firing rates (FRs) were similar. The stimulus-dependence of neuronal variability may result from the local network structure and/or the variability characteristics of the input signals, but may also reflect additional timing-based mechanisms independent of the neuron's mean FR and related to the modality driving the neuron.
    Cerebral Cortex 07/2012; · 8.31 Impact Factor
  • Annals of the New York Academy of Sciences 09/2011; 1233(1):ix-xi. · 4.38 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The rostral midbrain, especially the rostral interstitial nucleus of the medial longitudinal fasciculus (RIMLF) and the interstitial nucleus of Cajal (INC), plays an important role in the control of eye movements. Although the effect of midbrain lesions on eye movements is well investigated, little is known about its effect on head movements. In this study, we measured eye and head (gaze) movements in five patients with unilateral, acute midbrain lesions and nine healthy controls. In all patients, vertical eye velocity was reduced as a result of the lesion compared to healthy subjects, whereas peak head velocity was not affected. Further, most patients displayed an increased contralesional torsion in peripheral head positions, independently of whether they presented a head tilt in the straight-ahead position or not. Our results indicate that midbrain lesions affect the control of eye and head differently and independently.
    Annals of the New York Academy of Sciences 09/2011; 1233:71-7. · 4.38 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We introduce a novel approach for evaluation of neuronal tuning functions, which can be expressed by the conditional probability of observing a spike given any combination of independent variables. This probability can be estimated out of experimentally available data. By maximizing the mutual information between the probability distribution of the spike occurrence and that of the variables, the dependence of the spike on the input variables is maximized as well. We used this method to analyze the dependence of neuronal activity in cortical area MSTd on signals related to movement of the eye and retinal image movement.
    03/2011;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Neuronal tuning functions can be expressed by the conditional probability of observing a spike given any combination of explanatory variables. However, accurately determining such probabilistic tuning functions from experimental data poses several challenges such as finding the right combination of explanatory variables and determining their proper neuronal latencies. Here we present a novel approach of estimating and evaluating such probabilistic tuning functions, which offers a solution for these problems. By maximizing the mutual information between the probability distributions of spike occurrence and the variables, their neuronal latency can be estimated, and the dependence of neuronal activity on different combinations of variables can be measured. This method was used to analyze neuronal activity in cortical area MSTd in terms of dependence on signals related to eye and retinal image movement. Comparison with conventional feature detection and regression analysis techniques shows that our method offers distinct advantages, if the dependence does not match the regression model.
    Frontiers in Computational Neuroscience 01/2011; 5:15. · 2.48 Impact Factor
  • Clinical neurology and neurosurgery 10/2010; 113(2):150-2. · 1.30 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: When primates maintain their gaze directed toward a visual target (visual fixation), their eyes display a combination of miniature fast and slow movements. An involvement of the cerebellum in visual fixation is indicated by the severe gaze instabilities observed in patients suffering from cerebellar lesions. Recent studies in non-human primates have identified a cerebellar structure, the fastigial oculomotor region (FOR), as a major cerebellar output nucleus with projections toward oculomotor regions in the brain stem. Unilateral inactivation of the FOR leads to dysmetric visually guided saccades and to an offset in gaze direction when the animal fixates a visual target. However, the nature of this fixation offset is not fully understood. In the present work, we analyze the inactivation-induced effects on fixation. A novel technique is adopted to describe the generation of saccades when a target is being fixated (fixational saccades). We show that the offset is the result of a combination of impaired saccade accuracy and an altered encoding of the foveal target position. Because they are independent, we propose that these two impairments are mediated by the different projections of the FOR to the brain stem, in particular to the deep superior colliculus and the pontomedullary reticular formation. Our study demonstrates that the oculomotor cerebellum, through the activity in the FOR, regulates both the amplitude of fixational saccades and the position toward which the eyes must be directed, suggesting an involvement in the acquisition of visual information from the fovea.
    Journal of Neurophysiology 04/2010; 103(4):1988-2001. · 3.30 Impact Factor
  • Neurology 11/2009; 73(18):e92-3. · 8.30 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Several regions of the brain are involved in smooth-pursuit eye movement (SPEM) control, including the cortical areas MST (medial superior temporal) and FEF (frontal eye field). It has been shown that the eye-movement responses to a brief perturbation of the visual target during ongoing pursuit increases with higher pursuit velocities. To further investigate the underlying neuronal mechanism of this nonlinear dynamic gain control and the contributions of different cortical areas to it, we recorded from MSTd (dorsal division of the MST area) neurons in behaving monkeys (Macaca mulatta) during step-ramp SPEM (5-20 degrees /s) with and without superimposed target perturbation (one cycle, 5 Hz, +/-10 degrees /s). Smooth-pursuit-related MSTd neurons started to increase their activity on average 127 ms after eye-movement onset. Target perturbation consistently led to larger eye-movement responses and decreasing latencies with increasing ramp velocities, as predicted by dynamic gain control. For 36% of the smooth-pursuit-related MSTd neurons the eye-movement perturbation was accompanied by detectable changes in neuronal activity with a latency of 102 ms, with respect to the eye-movement response. The remaining smooth-pursuit-related MSTd neurons (64%) did not reflect the eye-movement perturbation. For the large majority of cases this finding could be predicted by the dynamic properties of the step-ramp responses. Almost all these MSTd neurons had large visual receptive fields responding to motion in preferred directions opposite to the optimal SPEM stimulus. Based on these findings it is unlikely that MSTd plays a major role for dynamic gain control and initiation of the perturbation response. However, neurons in MSTd could still participate in SPEM maintenance. Due to their visual field properties they could also play a role in other functions such as self-motion perception.
    Journal of Neurophysiology 11/2009; 103(1):519-30. · 3.30 Impact Factor
  • Ch. Helmchen, U. Büttner
    [Show abstract] [Hide abstract]
    ABSTRACT: Acquired forms of gaze-holding nystagmus usually produce centrifugal nystagmus. The authors report about a 63-year-old-patient with a rapidly deteriorating syndrome of cerebellar signs, dementia and myoclonus suggesting Creutzfeldt-Jakob disease (CJD), who developed the unusual sign of bilateral horizontal and vertical centripetal nystagmus with sustained eccentric fixation early in the disease. To our knowledge, this is the first report of centripetal nystagmus in CJD.
    07/2009; 15(4):187-192.
  • Kai Bötzel, Klaus Rottach, Ulrich Büttner
    [Show abstract] [Hide abstract]
    ABSTRACT: Dynamic overshoot (DO) of saccades was investigated in 17 normal subjects and 24 patients with central nervous lesions affecting the cerebellum and its connecting pathways, in order to detect and to define a pathological pattern of DO. Eye movements were recorded binocu-larly with the infrared reflection method. Normal subjects showed a high incidence of DO (average: 86% of all saccades) with an average amplitude of 0.16 deg (range of individual averages 0.08 to 0.41 deg). In 52% of all saccades DO occurred in both eyes and in 34% in one eye only. As in normals, the incidence of DO was too variable in patients to be used as a diagnostic tool. Six patients (out of 24) were considered to have pathological DO: their DO amplitudes (range of averages 0.57-0.99 deg) and/or left-right asymmetries exceeded the range of normal subjects. Three had multiple sclerosis, one a hereditary ataxia, one Friedreich's ataxia and one Wallenberg's syndrome. DO is considered to result from an alteration in the saccade braking (deceleration) pulse of immediate premotor structures in the brainstem. Recent experimental evidence suggests that the deceleration of saccades is also under the influence of the cerebellum (more specifically the fastigial nucleus and vermis). A comparison of saccadic dysmetria, often a pathological feature in cerebellar patients, with DO shows that they are not specifically interrelated to saccadic dysmetria. We suggest that pathological DO is probably not related to cerebellar dysfunction.
    Neuro-Ophthalmology 07/2009; 13(3):125-133. · 0.18 Impact Factor
  • Andreas Straube, Ulrich Büttner
    [Show abstract] [Hide abstract]
    ABSTRACT: Saccadic lateropulsion is a typical sign in Wallenberg's syndrome and midline lesions of the caudal cerebellum (oculomotor vermis, nucl. fastigii). There are only two reports on saccadic contrapulsion (contraversive to the side of the lesion) after a rostral cerebellar lesion. The authors describe a patient with an infarction in the area of the right medial branch of the superior cerebellar artery affecting the medio-lateral rostral cerebellum which showed a saccadic contrapulsion with hypermetric saccades to the left and hypermetric saccades to the right. Based on recent experimental neuro-physiological, anatomical and lesion studies, which demonstrate that the caudal fastigial nucleus is essential for accurate saccades, it is proposed that a lesion of the efferent pathways from the caudal fastigial nucleus to the direct premotor structures for saccades in the brainstem which cross within the cerebellum, causes the contrapulsion seen in the patient.
    07/2009; 14(1):3-7.
  • U. Büttner, Th. Brandt, Ch. Helmchen
    [Show abstract] [Hide abstract]
    ABSTRACT: Head-positioning maneuvers can lead to paroxysmal nystagmus and vertigo, which are usually due to a peripheral vestibular disorder like, for example, benign paroxysmal positioning vertigo (BPPV). They are less commonly caused by a central lesion (central paroxysmal positioning nystagmus, cPPV). While many typical features do not permit differentiation between BPPV and cPPV, for example, latency, course, and duration of nystagmus and vertigo during an attack, the direction of nystagmus often does. The nystagmus in BPPV always beats in the direction aligned to the affected semicircular canal plane, i.e., horizontal for the horizontal canal and vertical-torsional for the vertical canals. Any other direction (paroxysmal torsional, upbeat, or downbeat nystagmus) indicates a central origin. Three cases of cPPV exhibiting nystagmus in the latter directions are presented. In one of the cases with paroxysmal downbeat nystagmus and vertigo, all other parts of the neurological examination and brain imaging initially showed no lesion in the posterior fossa. The direction of nystagmus was the only sign that indicated a central origin.
    07/2009; 21(2):97-104.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Saccadic eye movements are generated by immediate premotor excitatory (EBN) and inhibitory (IBN) medium-lead burst neurons, long-lead burst neurons (LBN), and omnipause neurons (OPN) in the brainstem. The histological identification of the functional neuron populations is essential for performing any neuropathological analysis of clinical cases with saccadic disorders. This paper describes the localization of some premotor saccadic neurons in human brain and their neurochemistry, based on monkey data. In humans, the EBNs for horizontal saccades (EBNH) lie in the paramedian pontine reticular formation in the nucleus reticularis pontis caudalis (nrpc) and form a compact group of medium-sized neurons. The medium-sized IBNs lie caudal to the nucleus abducens in the nucleus paragigantocellularis dorsalis (pgd). The EBNs for vertical saccades (EBNV) are medium-sized neurons in the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF) in the rostral mesencephalon. The OPNs are located at the midline of the pontine reticular formation, in the nucleus raphe interpositus, bordered by the EBN area rostrally and the IBN area caudally. The OPNs use glycine as an inhibitory transmitter. These cell groups (EBNH, EBNV, IBN, and OPN) were first identified experimentally in monkeys, and all were shown to express parvalbumin im-munoreactivity. The parvalbumin immunoreactivity was then used as a marker to help identify the homologous neurons in man.
    07/2009; 16(4):229-240.
  • Stefan Kammermeier, Justus Kleine, Ulrich Büttner
    [Show abstract] [Hide abstract]
    ABSTRACT: Vestibulospinal reflexes are important for upright stance and locomotor control. Information from both the vestibular and the proprioceptive system must be combined centrally to guarantee appropriate compensation for a physical disturbance. Recent single-unit recordings from the monkey demonstrated vestibulo-proprioceptive interaction in the fastigial nucleus (deep cerebellar nucleus). The present study investigated whether integration of vestibular and proprioceptive signals is compromised in humans with cerebellar degeneration. Control subjects and patients were exposed to binaural, sinusoidal galvanic vestibular stimulation at 0.16 Hz, while their static head-on-trunk position was systematically altered in the head-horizontal plane from 60 degrees left to 60 degrees right. Controls responded to different head-on-trunk positions with fully compensatory changes in the direction of galvanically induced body sway, keeping it aligned with the head-frontal plane. In patients, this compensatory change was lacking. Findings support the assumption that the cerebellum plays a central role in the integration of vestibular and proprioceptive signals in humans. This form of impaired sensory interaction is probably a clinically important component of cerebellar stance and gait ataxia.
    Annals of the New York Academy of Sciences 06/2009; 1164:394-9. · 4.38 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Downbeat nystagmus (DBN) is rarely caused by lesions in sites other than the cerebellar (para-)floccular lobe. We describe a case of DBN secondary to a hemorrhaged venous cavernoma at the pontomedullary junction. This case provides new insights into the neuro-anatomical substrate of DBN. We propose that DBN arises from lesions in a brainstem-cerebellar feedback loop, which comprises cells of the pontine paramedian tract (PMT).
    Journal of Neurology 06/2009; 256(9):1572-4. · 3.58 Impact Factor
  • Michael Strupp, Ulrich Büttner, Bernard Cohen
    Annals of the New York Academy of Sciences 06/2009; 1164:xi-xii. · 4.38 Impact Factor

Publication Stats

2k Citations
441.02 Total Impact Points

Institutions

  • 1991–2012
    • Ludwig-Maximilian-University of Munich
      • • Department of Neurology
      • • Institute of Clinical Neurosciences
      München, Bavaria, Germany
  • 2008–2009
    • Bernstein Center for Computational Neuroscience Berlin
      Berlín, Berlin, Germany
  • 1976–2008
    • University of Zurich
      • • Division of Neuropsychology
      • • The KEY Institute for Brain-Mind Research
      Zürich, ZH, Switzerland
  • 2003
    • Universität zu Lübeck
      Lübeck Hansestadt, Schleswig-Holstein, Germany
  • 2002
    • Academy of Sciences of the Czech Republic
      • Fyziologický ústav
      Praha, Hlavni mesto Praha, Czech Republic
  • 1983–1985
    • Heinrich-Heine-Universität Düsseldorf
      • • Neurologische Klinik
      • • Department of Urology
      Düsseldorf, North Rhine-Westphalia, Germany
  • 1977
    • Psychiatrische Universitätsklinik Zürich
      Zürich, Zurich, Switzerland