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  • Cerebellum  (9)
  • Cortical field potential  (5)
  • Audio-initiated hand movement  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 46 (1982), S. 29-36 
    ISSN: 1432-1106
    Keywords: Premovement cortical potential ; Visually initiated movement ; Cerebellum ; Monkey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cortical field potentials preceding hand movements initiated by a visual stimulus were recorded with chronically implanted electrodes in premotor, motor and somatosensory cortices of monkeys, and the influences of cerebellar hemispherectomy on cortical potentials as well as reaction time of movements were examined. As reported previously, early surface-positive, depth-negative (2.5–3 mm depth from the cortical surface) premovement potentials emerged at about 40 ms latency after onset of the light stimulus bilaterally in premotor and forelimb motor areas. Early potentials in the forelimb motor area contralateral to the moving hand were followed at about 120 ms latency by surface-negative, depth-positive late premovement potentials which are considered to be mainly composed of superficial thalamo-cortical (T-C) responses. Unilateral hemispherectomy of the cerebellum contralateral to the motor area immediately eliminated the surface-negative, depth-positive potentials. Reaction time from onset of the light stimulus to the hand movement was prolonged by 90–250 ms after cerebellar hemispherectomy. If the dentate and interpositus nuclei were also lesioned, disappearance of the late potentials and delay of the movement continued for many months. However, if the interpositus was spared, there was earlier recovery of reaction time with simultaneous reappearance of the late premovement potentials in the motor cortex. The conclusion is drawn that the cerebellar hemisphere (neocerebellum) activates the motor cortex via superficial T-C projections and participates directly in the initiation of reaction movements in response to an external stimulus.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 65 (1987), S. 649-657 
    ISSN: 1432-1106
    Keywords: Audio-initiated hand movement ; Cortical field potential ; Cerebellar hemispherectomy ; Monkey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Monkeys were trained to respond to auditory stimulus by lifting a lever (audio-initiated hand movement), and field potentials were recorded. from various cortical areas with electrodes implanted on the surface and at a depth of 2.0–3.0mm, depending on the area. Tones of 500, 1000 and 2000 Hz were given to the monkey for about 500 or 10 ms, as auditory stimuli. In association with the movement, potentials of different configurations were recorded respectively in the primary auditory, auditory association, prefrontal, premotor, motor and somatosensory cortices. Initial surface-positive (s-P), depthnegative (d-N) potentials appeared in the primary auditory and auditory association cortices about 20 ms after the onset of the auditory stimulus, and they were often followed by s-N, d-P potentials. In the forelimb area of the motor cortex contralateral to the moving hand, s-N, d-P potentials appeared at a latency of about 100 ms. Following cerebellar hemispherectomy ipsilateral to the moving hand, the s-N, d-P potentials in the forelimb motor cortex were eliminated and reaction times prolonged. The same monkeys were also trained to perform a visuoinitiated movement, and results were compared with each other. Primary sensory and sensory association areas activated during such movements were certainly different, and the prefrontal association cortex appeared to participate much less predominantly in the audio- than in the visuo-initiated movement. Reaction times were generally longer and more variable for the audio- than for the visuo-initiated movement. Nevertheless the cerebello-thalamomotor cortical projection was found to be recruited in the same manner prior to both movements.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 55 (1984), S. 26-32 
    ISSN: 1432-1106
    Keywords: Cortical field potential ; Visually initiated movement ; Motor learning ; Monkey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A monkey was trained to lift a lever by wrist extension in response to a light stimulus. During the learning process of the task over several months, field potentials related not only to the task performance but also to substitution and stimulation experiments were recorded with chronically implanted electrodes on the surface and at a depth of 2.5–3.0 mm in the prefrontal, premotor, motor and prestriate cortices. In the substitution experiment, an examiner lifted a lever for the monkey so that it was watching the light and rewarded without the hand movement. In the stimulation experiment, the same light stimulus was simply delivered to the monkey. In a naive monkey which lifted the lever independently of the stimulus, stimulus-locked potentials were evoked by the task experiment in those cortices except the motor cortex, but none was elicited by the substitution or stimulation experiment. In a welltrained monkey, the substitution and stimulation experiments induced almost the same potentials as those prior to the task movement in respective cortices except the motor cortex, in which the component of cerebellar-induced premovement potential was not observed during the substitution and stimulation experiments. At an intermediate stage of learning, the situation was intermediate between the naive and well-trained stages and most premovement potentials except those in the motor cortex were elicited by the substitution experiment in reduced sizes, but nothing by the stimulation experiment. The present study suggests that the neuronal circuits for the operantly conditioned movement are functionally organized and gradually consolidated in the learning process, and that the consolidation is made earlier for the circuit involving association and premotor cortices than the circuit including the motor cortex in the process. The circuit to the motor cortex via the cerebro-cerebellar interconnection is recruited only on the execution of movement.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 70 (1988), S. 43-49 
    ISSN: 1432-1106
    Keywords: Audio-initiated hand movement ; Cortical field potential ; Motor learning ; Monkey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Field potentials on the surface and at a depth of 2.0–3.0 mm in the cerebral cortex were recorded with chronically implanted electrodes in various areas of a monkey. The potentials associated with movements in response to auditory stimuli (audio-initiated hand movement) were observed during the learning process of the movement. The monkey had to lift a lever by wrist extension within the duration of the stimulus (tone of 1000 Hz) lasting for about 900, 700 or 500 ms depending on the stage of the learning process. On the first training day, potentials appeared in the primary auditory, auditory association, prefrontal and premotor cortices of a naive monkey. The potentials of the auditory association, prefrontal and premotor cortices became less marked on the next and following days. After a few weeks of training, the potential of the auditory association cortex started to increase again, while the monkey still lifted the lever randomly. When the potential of the auditory association cortex grew to a certain extent, the monkey began to respond to the stimulus with the movement, and potentials appeared in the motor cortex in response to the auditory stimulus. After this process, the potentials in the auditory association and motor cortices gradually increased with further training, and the movement became shorter and less variable in reaction time. The potential in the motor cortex was shown to be mediated by the neocerebellum and superficial thalamo-cortical projection. The changes of potentials associated with the learning processes of audio-initiated movements were respectively compared with those of the learning processes of the visuo-initiated movement, reported previously (Sasaki and Gemba 1982), and cortical and subcortical mechanisms related to the learning process were discussed.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 48 (1982), S. 429-437 
    ISSN: 1432-1106
    Keywords: Cortical field potential ; Visually initiated movement ; Motor learning ; Monkey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Field potentials on the surface and at 2.5–3.0 mm depth in the cerebral cortex were recorded in various areas with chronically implanted electrodes and the potentials which preceded hand movements in response to a light stimulus were observed during the process of learning the skilled conditioned movement. A naive monkey had to lift a lever by wrist extension within duration of the light stimulus lasting for 900, 700 or 510 ms depending on the stage of the learning process. In addition to some responses in the striate gyrus, significant short-latency responses to the light stimulus appeared bilaterally in certain areas of the prefrontal and prestriate cortices at an early stage of learning in which the monkey still lifted the lever randomly, and they became gradually larger as the monkey was trained further. Short-latency responses were also often noted in the bilateral premotor cortices during an early stage of learning. When the monkey started to respond to the stimulus by the appropriate movement, early surface-positive (s-P), depth-negative (d-N) premovement potentials appeared in the forelimb motor cortex, and the responses in the premotor cortex increased in size. As the movement became faster and more skillful, late s-N, d-P premovement potentials, that are known to be mediated by the neocerebellum and superficial thalamo-cortical projections, emerged after the early s-P, d-N potentials and became more marked, larger and steeper in the forelimb motor cortex contralateral to the moving hand. All the premovement potentials in the different cortical areas thus developed into steady and constant states and remained so for many months thus maintaining their established patterns. Such successive appearances of premovement field potentials in various cortical areas were related to learning processes of the movement and the implication of these findings was discussed.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-1106
    Keywords: Prefrontal cortex ; Cortical field potential ; Reaction time movement ; Colour discrimination ; Monkey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Monkeys were trained to perform hand movements in a reaction time task with discrimination between positive (go) and negative (no-go) light signals, and field potentials in various cortical areas were recorded and analysed with chronically implanted cortical electrodes. As previously reported, areas such as the prefrontal, premotor and motor cortices were active in association with simple visually-initiated, reaction-time hand movements. The caudal part of the dorsal bank of the principal sulcus was found to be activated specifically on no-go trials during discrimination, and revealed a relatively sharp surface-negative, depth-positive potential. The potential appeared at a latency of 110–150 ms, which was 150–210 ms earlier than the movement onset on go trials. With reversal of the go and no-go signals, this potential was found to be recorded only on no-go trials, irrespective of the colour used for the stimulus. It is suggested that the activity in the dorsal bank of the principal sulcus is related to the judgement not to execute the movement and/or the suppression of motor execution.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 16 (1972), S. 89-103 
    ISSN: 1432-1106
    Keywords: Cerebellum ; Thalamus ; Parietal Cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The cerebello-thalamo-cerebral projection system mediating the cerebellar-induced “superficial thalamo-cortical (T-C) response” (the basic type of the so-called recruiting response) to the anterior part of the middle suprasylvian gyrus was investigated electrophysiologically. Responses of thalamic neurones to stimulation of the cerebral cortex and the cerebellar nucleus (medial, interpositus and lateral) were recorded by microelectrodes. 2. In the anterior portions of the ventral thalamic nuclear complex, presumably in and/or around the ventral anterior (VA) nucleus, there were found neurones responding antidromically to stimulation of the suprasylvian cortex and orthodromically to that of the interpositus and the lateral nucleus of the cerebellum. They were called P neurones. The neurones responding antidromically to stimulation of the anterior sigmoid cortex and orthodromically to that of the cerebellar nuclei located mostly caudo ventrolateral to the place of P neurones, presumably in and/or around the ventral lateral (VL) nucleus. These were called F neurones. 3. The cerebellar excitation of P neurones was estimated on its latency to be monosynaptic and was usually followed by an inhibition lasting for more than 100 msec. Large unitary EPSPs were sometimes noted in P neurones on cerebellar stimulation as well as spontaneously. It was concluded that P neurones constitute the direct T-C projection system mediating the superficial T-C response (e. g., recruiting response) to the parietal cortex.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 16 (1972), S. 75-88 
    ISSN: 1432-1106
    Keywords: Cerebellum ; Thalamus ; Cerebral Cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Cerebello-cerebral projections were electrophysiologically investigated in cats under light Nembutal anaesthesia. Marked responses were produced by stimulation of the interpositus and the lateral nucleus of the cerebellum not only in the pericruciate but also in the suprasylvian cortical areas, both areas being contralateral to the cerebellar nuclei stimulated. Medial nucleus stimulation set up little or no response in the cerebral cortex. 2. The previous electrophysiological study on thalamo-cortical (T-C) projections showed two different kinds of responses in the cortex due presumably to two different T-C projection systems, i. e., deep and superficial T-C responses (see Sasaki et al., 1970). According to laminar field potential analysis, the response in the pericruciate area is characterized by a deep T-C response which is often followed by a superficial T-C response, whereas the response in the parietal cortex consists of a pure superficial T-C response. Intracellular potential changes in cortical neurones elicited by cerebellar nucleus stimulation were consistent with the results of laminar field potential analysis. 3. Comparison between laminar field potentials in the same cortex produced by thalamic and cerebellar nucleus stimulation suggests that the response in the pericruciate cortex is mediated by the ventral lateral nucleus and that the response in the parietal cortex is relayed by the ventral anterior nucleus of the thalamus.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 2 (1966), S. 18-34 
    ISSN: 1432-1106
    Keywords: Cerebellum ; Parallel fibres ; Basket cells ; Purkinje cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Stimulation through concentric electrodes on the surface of a wide cerebellar folium was employed to set up a parallel fibre volley or beam. Serial recording of the field potential was made over a range of depths along microelectrode tracks arranged in a transverse plane across the folium in order to discover the action on Purkinje cells, both those that were on-beam for the parallel fibre volley and those at various distances off-beam. A juxta-fastigial electrode was carefully placed so that an applied stimulus could excite the axons of Purkinje cells distributed across the folium under investigation, the antidromic propagation of impulses thus obtained being utilized to test the effect of parallel fibre volleys upon Purkinje cells. 2. The observations were in accord with the two actions that a parallel fibre volley would be expected to exert on Purkinje cells: a direct excitatory action by the synapses made by parallel fibres with the spines of the Purkinje cell dendrites; an inhibitory action mediated by the stellate and basket cells that themselves are directly excited by the parallel fibre volley. 3. The excitatory synaptic action would result in the two types of responses that were restricted to the narrow zone and superficial location of the parallel fibre volley: active sinks formed by this excitatory synaptic action on the superficial dendrites of Purkinje cells would account for the observed depth profile of extra-cellular slow potentials, a superficial negative wave reversing to a deeper positive wave formed by passive sources on deeper dendrites; superficial synaptic excitation would also account for the facilitation of the propagation of antidromic impulses into the superficial dendrites. 4. The inhibitory synaptic action would result in the two types of responses that were widely dispersed transversely and in depth, far beyond the traject of the parallel fibre volley: a slow positive potential wave with a maximum at a depth usually of 300–400 μ; an inhibitory action on the antidromic invasion of Purkinje cells. The transverse profiles of these two presumed indices of inhibitory action on Purkinje cells apparently revealed that a basket cell may give inhibitory synapses up to 1000 μ laterally from the location of its soma and dendrites. 5. A description is given of the variants in the transverse profiles of the deeper positive waves and of inhibitory actions of a parallel fibre volley that presumably are mediated by basket cells and also by the superficial stellate cells. These physiological findings are correlated with the histologically determined distribution of synapses from a basket cell onto Purkinje cells.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 3 (1967), S. 95-110 
    ISSN: 1432-1106
    Keywords: Mossy fibre pathways ; Cerebellum ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Field potentials in the vermal cerebellar cortex generated by a mossy fibre volley along reticulo-, cuneo- and spino-cerebellar tracts were recorded with microelectrodes and analysed by the same procedures as was done for the mossy fibre responses in the cortex by juxta-fastigial (J.F.) and trans-folial (T.F.) stimulations in the previous paper (Eccles, Sasaki and Strata 1967a). li 3. All these results corroborate the analyses and the interpretations of the field potentials in the cerebellar cortex produced by T.F.- and J.F.-evoked mossy fibre volleys in the previous paper. 4. There have not been found electrophysiologically significant differences, as Szentágothai (1964) has suggested, between the modes of mossy fibre terminations of the reticulo-cerebellar and the spino-cerebellar systems.
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