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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 57 (1979), S. 1303-1304 
    ISSN: 1432-1440
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 17 (1973), S. 50-62 
    ISSN: 1432-1106
    Keywords: Cerebellum ; Barbiturates ; Unitary activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In precollicular decerebrate cats, limb nerves have been stimulated and field potentials and unitary activity recorded from the cerebellar cortex. Doses of pentothal up to 8 mg/kg affect neither the activity evoked in the fast mossy fibre pathways, nor the size of the postsynaptic potentials in granule cells, but the axon discharge in these latter cells is clearly affected. With 4–8 mg/kg the axon discharge of granule cells is abolished and as a consequence Purkinje cells do not respond to the peripheral stimulation via the mossy fibres. In contrast the activity evoked through the climbing fibres is enhanced. This effect takes place at precerebellar level. Both the effects on the mossy fibre and climbing fibre pathways show a recovery in 15–60 min depending on the dose.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 31 (1978), S. 387-401 
    ISSN: 1432-1106
    Keywords: Passive movement ; Cerebellar cortex ; Mossy and climbing fiber input ; Granular cells ; Purkinje cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The responses of mossy fibers (MF), granular cells (GrC) and Purkinje cells (PC) were recorded in the cerebellum of the decerebrate cat during a passive movement about the forepaw wrist joint. Three main discharge patterns containing information about all the static and dynamic parameters of the movement were found. Simultaneous recording of complex spikes (CS) and simple spikes (SS) showed that the activity of PC can be modulated through either MF or CF input channels alone or both together. In the latter case SS and CS discharge most commonly showed an opposite behavior, in which the increase of the frequency of one type of spike was accompanied by a decrease of the frequency of the other type. Both inputs displayed tonic and phasic characteristics and all the qualitative discharge patterns observed. Therefore it was concluded that aside from differences in the discharge frequency, both inputs are able to directly signal peripheral events.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 38 (1980), S. 363-373 
    ISSN: 1432-1106
    Keywords: Passive movements ; Cerebellar cortex ; Climbing fiber input ; Purkinje cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Discharges of Purkinje cells (PCs) with simple (SS) and complex spikes (CS) in the c1zone of lobule Vc of the anterior lobe of the cerebellar cortex were analyzed in the decerebrate cat during a passive movement of the cat forepaw. The CS of the PC responded differentially and/or proportionally to the position of the extremity, amplitude of the movement, velocity and acceleration. Inphase and outphase responses of the climbing fiber (CF) system to sinusoidal movements could depend on the position of the extremity within the operational range. From these results we deduce that peripheral events can be signalled by the CF system. The possible function of the interaction between the two inputs at the PC level is discussed.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 68 (1987), S. 219-233 
    ISSN: 1432-1106
    Keywords: Cerebellar cortex ; Comparative analysis ; Passive movement ; Decerebrate cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1) The present experiments were undertaken to study how information about the parameters of a passive movement is processed at different neuronal levels of the cat cerebellar cortex. The analysis has been performed by recording extracellularly in the intermediate part of the cerebellar anterior lobe from presumed mossy fibres, presumed granule cells, and Purkinje cells with simple spikes and complex spikes. 2) The discharge patterns obtained during passive movements of the cat's forepaw were characterized by components which could be related to dynamic or static parameters of the movement. With respect to the occurrence of dynamic responses, patterns were classified according to a statistically derived measure in three different types. By using the same statistical measure, discharge patterns were additionally classified into two subgroups according to their response components reflecting static parameters. Within the patterns a clearcut relationship between dynamic and static components was observed. The corresponding distributions are shown and discussed. 3) A very interesting result of the classification of cerebellar discharge patterns is that the distribution of the different types depended on the level of integration within the cerebellar cortex. Patterns of the low scale integrated cerebellar input (mossy fibre-system), as well as those of granule cells (the first cerebellar computational niveau), reflected both static and dynamic movement parameters. At the Purkinje cell level (a level with a high degree of convergence) the discharge patterns are characterized predominantly by dynamic responses. 4) The interrelationship between complex- and simple spikes of Purkinje cells was tested by different methods: a) By analyzing the paired values of the mean complex-(CS) and simple spike (SS) discharge probabilities of 110 Purkinje cells a scatter was obtained, indicating an underlying hyperbolic relation (prob(CS) = a/(prob(SS))b). Thus, a high CS discharge probability is accompanied by a low SS probability and vice versa, b) The timelocked complex- and simple spike responses were studied by comparing the similarity of their responses. All combinations of complex- and simple spike patterns were observed, ranging from a sign correct similarity to a mirror image similarity. The distribution of the measure for similarity shows that the mirror image predominated, c) The individual simple spike discharge probability is characterized by a pause evoked by the occurrence of a complex spike event. The simple spike discharge probabilities during an interval preceeding and following a complex spike event were compared. A post climbing pause coefficient was defined as a measure for the effectiveness of the complex spike event. No relationship between these coefficients and the above mentioned measure for similarity was found. Hence, for the Purkinje cell discharging with the simple spikes independent spike generating processes have to be assumed. 5) From these results it can be derived that cerebellar discharge patterns can be classified with respect to responses to static and dynamic parameters of passive limb movements. Based on this classification it appears that the distribution of responses to static and dynamic parameters depends on the computational level within the cerebellar cortex. If both static and dynamic parameters are conveyed by a single unit, a clear relationship between the response components could be observed. However, this effect was independently found at all cerebellar cortical computational levels indicating a functional principle of processing a pair of movement parameters. The interrelation of complex- and simple spike responses to passive movement was further studied. Since transients of complex- and simple spike patterns were observed ranging from two almost identical patterns to mirror image like patterns, it is assumed that under physiological conditions one of the tasks of the climbing fibre system consists of tuning the simple spike discharge according to the peripheral requirements.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 68 (1987), S. 234-248 
    ISSN: 1432-1106
    Keywords: Passive movements ; Cerebellar cortex ; Mossy fibre system ; Static movement parameters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1) Experiments were designed to detect how static parameters of natural, passive hand movements are encoded and integrated within the cerebellar cortex. For this purpose unit activity was recorded extracellularly from presumed mossy fibres (MF), presumed granule cells (GrC) and from Purkinje cells (PC) discharging with simple spikes (SS) and complex spikes (CS). With respect to the PC, our interest was focussed primarily on the SS activity. The recordings were performed in the intermediate part of the cerebellar anterior lobe of decerebrate cats. The animal's forepaw was passively moved around the wrist joint by an electronically controlled device. The movements were exactly reproducible so that peristimulus time histograms of the unit activity could be constructed. 2) At the input level (MF) and at the first level of integration within the cerebellar cortex (GrC), patterns with similar discharge characteristics were found. Such patterns could, to a limited extent, also be detected at the cerebellar output (SS of PC). However, in most cases of SS discharge, patterns were found with weak correlation between the tonic activity and static parameters of the movements. 3) Absolute paw position, amplitude, and duration of movements were found to be related over wide ranges to the activities of MF and GrC. Absolute position is directly encoded by tonic discharge during the low or high holding phases. Beside this, units were found without a correlation between the tonic discharge and the position of the nonmoving paw. However, in these units it was sometimes observed that the information about the momentary position or the information about the mean position was sometimes conveyed exclusively during the proceeding upward or downward movement. Thus, information about static parameters was transmitted only at times when a dynamic parameter (such as velocity) occurred. This type of position information encoding is termed “indirect mode of transmission”. 4) A specific relationship between SS unit activity of PC and the absolute position of the forepaw or amplitude of the movement could be found primarily by using multiple ramps instead of single ramp movements. This was observed even if both types of ramp movements had the same velocity, individual amplitude, and tested range. However, on multiple ramp movements the paw generally remained for a shorter period at a specific position level as compared to the single ramp movements. 5) Apart from this timing phenomenon, a late movement response was observed, which results in a specific type of position information encoding on multiple ramp functions. 6) These results indicate that static parameters of a passive limb movement are conveyed via the MF input to the cerebellar cortex. Patterns related to these parameters undergo a change within the MF-, GrC-, Parallel fibre-, PC-system. Different modes of encoding these parameters were observed depending primarily on the neuronal niveau within the cerebellar cortex. Tonic discharge related e.g. to limb position was found at MF and GrC level. Such patterns resemble, at least to a certain extent, those obtained from different peripheral receptors. The high tonic SS activity never showed such a strong relationship to static parameters as observed at the input level; static parameters could be resolved only within relatively short periods of time, especially during the dynamic phases of the movement or during short periods immediately following these phases. This implies that the function of this part of the cerebellum, which is to provide correction signals, should be considered as a more dynamic process characterized by evaluating predominantly information about the momentary ongoing movement.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 42 (1981), S. 249-259 
    ISSN: 1432-1106
    Keywords: Passive movement ; Cerebellar cortex ; Climbing fiber and mossy fiber system ; Granule cells ; Purkinje cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the decerebrate cat discharges of Purkinje cells with simple and complex spikes as well as granule cell discharges in the c1-zone of lobules Va, b and c of the cerebellar anterior lobe were analyzed during a passive movement of the cat's forepaw. Penetrations were made 50 μm apart along the mediolateral and parasagittal directions, the depth never exceeding 500 μm. The response of the Purkinje cells to the climbing fiber input was surprisingly constant, while simple spike responses of the same cells showed a great variability to the same input. The variability between granule cell discharges recorded at a 50 μm distance from each other was similar to that of the simple spikes of the Purkinje cell. It is assumed that because of a patchy distribution of excited granule cells, two neighbouring Purkinje cells may receive a different information via their parallel fiber inputs. This difference is considered to be responsible for the great variability of their responses to mossy fiber inputs.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 314 (1970), S. 68-85 
    ISSN: 1432-2013
    Keywords: Cerebellärer Cortex ; Faserentladungen ; Evoked Potentials ; Cerebellar Cortex ; Fiber Responses ; Evoked Potentials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary To investigate the relationship between the surface evoked potentials of the superficial radial nerve and the splanchnic nerve, and the fiber evoked responses of the cerebellum of the cat was the purpose of the present study. The discharges of the mossy fibers, climbing fibers and Purkinje cell axons were identified and their relationship with the surface-potentials established. The mossy fibers fire with train of spikes in different groups, which probably correspond to impulses transmitted through fibers of different conduction velocities and synchronously with the first positivity of the evoked potential. Climbing fibers respond synchronously with the development of the sharp negative deflection of the evoked potentials and were, for the first time, identified. Finally, the Purkinje cell axons exhibited the same firing pattern as the Purkinje cells. Cutaneous and visceral afferents use not only common elements of the cerebellar cortex but also common pathways, in spite of measurable differences between both afferents.
    Notes: Zusammenfassung Der Zweck der vorliegenden Arbeit war die Beschreibung der Beziehung zwischen den Oberflächen-Evoked Potentials, ausgelöst durch Reizung des N. radialis superficialis und des N. splanchnicus und den evozierten Faserentladungen am Kleinhirn der Katze. Die Entladungen der Moosfasern, Kletterfasern und Axone der Purkinje-Zelle wurden identifiziert und ihre Beziehung zu den Oberflächenpotentialen festgestellt. Die Moosfasern feuern mit Spikesalven und in verschiedenen Gruppen. Diese entsprechen wahrscheinlich Impulsen, die von Fasern mit verschiedener Leitungsgeschwindigkeit fortgeleitet werden und die synchron mit der ersten Positivität der Evoked Potentials sind. Die Kletterfasern stehen in zeitlicher Beziehung zu der Entwicklung der scharfen negativen Ablenkung des EPs und werden zum ersten Male identifiziert. Schließlich weisen die Axone der Purkinje-Zelle dieselben Entladungsmuster auf wie die Purkinje-Zelle selbst. Cutane und viscerale Afferenzen benutzen nicht nur gemeinsame Elemente des cerebellären Cortex, sondern wahrscheinlich auch gemeinsame Leitungswege, obwohl es quantitative Differenzen zwischen beiden Afferenzen gibt.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-2013
    Keywords: Cerebellärer Cortex ; Instrumentelle Konditionierung ; Licht-Dunkelheit-Diskrimination ; Cerebellar Cortex ; Instrumental Conditioning ; Light-Dark-Discrimination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Eighteen cats were used as subjects in a study which investigated the effects of bilateral cortical cerebellar hemispheric ablations upon light-dark discrimination learning. From the operated control group (8 animals), 5 were tested two weeks and 3 three weeks postoperatively. From the experimental group (10 animals) 4 were tested two weeks and 6 three weeks postoperatively. The discrimination task consisted of an instrumentally conditioned bar-pressing response. The results showed that almost during the entire 23-day learning period, the experimental cats performed more poorly on the discrimination task than their controls. It is hypothesized that the difference between the two groups of animals derives from the disturbance (caused by the ablation) of the connections between the cerebellum and other structures involved in the habituation process.
    Notes: Zusammenfassung 18 Katzen wurden als Versuchstiere in einem Experiment benutzt, welches den Einfluß der bilateralen Entfernung des corticalen Teils der cerebellären Hemisphären auf das Erlernen einer Licht-Dunkelheit-Diskrimination untersuchte. Von der operierten Kontrollgruppe (8 Tiere) wurden 5 zwei Wochen und 3 drei Wochen nach der Operation getestet. Von der experimentellen Gruppe (10 Tiere) wurden 4 zwei Wochen und 6 drei Wochen nach der Operation getestet. Die Diskriminationsaufgabe bestand aus Hebeldrücken nach der Skinner-Methode. Die Ergebnisse zeigten, daß die experimentellen Tiere fast während der ganzen Lernperiode (23 Tage) weniger Diskriminationsvermögen aufweisen als die Kontrolltiere. Es wurde vermutet, daß dieser Unterschied zwischen den experimentellen Tieren und den Kontrolltieren darauf beruht, daß die Entfernung eines Teils des cerebellären Cortex die Verbindungen zu Strukturen, die bei dem Habituationsprozeß eine Rolle spielen, stört.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 284 (1965), S. 273-277 
    ISSN: 1432-2013
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A new method for intracerebral stimulation of unanesthetized and unrestrained cats has been described. This method permits one to change the target several times in the awake animal until the desired stimulation effect is obtained. The electrode socket contains a ball-joint which can be aimed at different targets according to a stereotaxic brain atlas.
    Type of Medium: Electronic Resource
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