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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 1 (1966), S. 1-16 
    ISSN: 1432-1106
    Keywords: Inhibitory interneurones ; Cerebellum ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Extracellular microelectrode recording has been employed to study the responses of three types of interneurones in the cat cerebellar cortex: basket cells, superficial stellate cells and Golgi cells. The large unitary spike potentials of single cells were sharply localized and presumably were generated by impulse discharges from the cell somata. The characteristics of their responses described below sharply distinguished them from Purkinje cells. 2. The parallel fibre volleys generated by surface stimulation of a folium evoked brief repetitive discharges that were graded in respect of frequency and number. Maximum responses had as many as 10 impulses at an initial frequency of 500/sec. 3. At brief test intervals there was facilitation of the response to a second parallel fibre volley; at about 50 msec it passed over to depression for over 500 msec. 4. Stimulation deep in the cerebellum in the region of the fastigial nucleus (juxta-fastigial, J.F.) evoked by synaptic action a single or double discharge, presumably by the mossy fibre-granule cell-parallel fibre path, but climbing fibre stimulation from the inferior olive also usually had a weak excitatory action evoking never more than one impulse. 5. J.F. stimulation also had an inhibitory action on the repetitive discharge evoked by a parallel fibre volley. Possibly this is due to the inhibitory action of impulses in Purkinje cell axon collaterals. 6. There was a slow (7–30/sec) and rather irregular background discharge from all interneurones. The inhibitory actions of parallel fibre and J.F. stimulation silenced this discharge for some hundreds of milliseconds, probably by Golgi cell inhibition of a background mossy fibre input into granule cells. 7. All these various features were displayed by cells at depths from 180 to 500 μ; hence it was concluded that superficial stellate, basket and Golgi cells have similar properties, discrimination being possible only by depth, the respective depth ranges being superficial to 250μ, 250μ to 400μ, and deeper than 400μ.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 1 (1966), S. 17-39 
    ISSN: 1432-1106
    Keywords: Parallel fibres ; Purkinje cells ; Cerebellum ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. When electrical stimuli were applied to the surface of a cerebellar folium by a local electrode (LOC), there was a propagated potential wave along the folium with a triphasic (positive-negative-positive) configuration. 2. Investigations by microelectrode recording established that this wave is produced by impulses propagating for at least 3 mm and at about 0.3 m/sec along a narrow superficial band or “beam” of parallel fibres. As expected from this interpretation, there was an absolutely refractory period of less than 1 msec and impulse annihilation by collision. 3. Complications occurred from the potential wave forms resulting from the excitation of mossy fibres by spreading of the applied LOC stimulus. These complications have been eliminated by chronically deafferenting the cerebellum. 4. When recording within the beam of excited parallel fibres there was a slow negative wave of about 20 msec duration, and deep and lateral thereto, there was a slow positive wave of approximately the same time course. 5. These potential fields were expressed in serial profile plots and in potential contour diagrams and shown to be explicable by the excitatory and inhibitory synaptic action on Purkinje cells: excitatory depolarizing synapses of parallel fibre impulses on the dendrites; and hyperpolarizing inhibitory synapses of stellate and basket cells respectively on the dendrites and somata. The active excitatory synapses would be strictly on the parallel fibre beam and the inhibitory concentrated deep and lateral thereto, which is in conformity with the axonal distributions of those basket and stellate cells that would be excited by the parallel fibre beam. 6. Complex problems were involved in interpretation of slow potentials produced by a second LOC stimulus at brief stimulus intervals and up to 50 msec: there was a potentiation of the slow negative wave, and often depression of the positive wave deep and lateral to the excited beam of parallel fibres. 7. Often the LOC stimulus evoked impulse discharge from the Purkinje cells, these discharges being inhibited by a preceding LOC stimulus.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 1 (1966), S. 82-101 
    ISSN: 1432-1106
    Keywords: Cerebellum ; Mossy fibre input ; olgi cell inhibition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The glomerulus in the cerebellar granular layer is composed of the three elements; the mossy fibre terminal, the granule cell dendrites and the Golgi cell axons. The afferent input to the cerebellar cortex through the glomerulus, the mossy fibre-granule cell relay (M.G.R.), and its inhibitory control by the Golgi cells were studied by recording, a) extracellular field potentials in the granular and molecular layers, b) unitary spikes of granule cells, and c) intracellular postsynaptic potentials in Purkinje cells. 2. Mossy fibres were activated by juxta-fastigial, transfolial, lateral cuneate nucleus and radial nerve stimulation. Stimulation of an adjacent folium (transfolial stimulation) could excite branches of mossy fibres under the stimulating electrode which supply other branches also to the folium under the recording electrode. This technique was utilized to distinguish the response due to mossy fibre activation from those due to the climbing fibre and Purkinje cell axons. 3. These stimulations resulted in, through the M.G.R., a powerful activation of granule cells whose axons (parallel fibres) excited in turn the Purkinje cells and the inhibitory interneurones, including the Golgi cells, in the molecular layer. 4. Field potentials and unitary spikes due to granule cell activity elicited by the stimulation of mossy fibres were markedly depressed for hundreds of milliseconds after the direct stimulation of parallel fibres (LOC stimulation). The postsynaptic potential in Purkinje cells evoked by mossy fibre activation was also depressed by the conditioning LOC stimulation in the same manner. The “spontaneous” background activities recorded from granule cells as unitary spikes and from Purkinje cells as inhibitory synaptic noise were silenced for hundreds of milliseconds after the LOC stimulation. 5. These depressions indicate that the parallel fibre activation evokes an inhibitory action upon M.G.R. On anatomical grounds this inhibition can be mediated only by the Golgi cell, and it is postulated that the inhibitory action is postsynaptic upon the dendrites of granule cells. 6. It is concluded that the Golgi cell inhibition regulates the mossy fibre input to the cerebellar cortex at the M.G.R. by a form of negative feed-back.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 1 (1966), S. 161-183 
    ISSN: 1432-1106
    Keywords: Cerebellum ; Purkinje cells ; Intracellular recording ; Postsynaptic potentials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Intracellular recording from Purkinje cells has been employed in investigating the excitatory and inhibitory synaptic action that is exerted on these cells by the mossy fibre input into the cerebellum. 2. These synaptic actions are evoked not directly by the mossy fibres, but probably always through granule cells and their axons, the parallel fibres. The intracellular records conform with the anatomical evidence that the parallel fibres directly exert a powerful synaptic excitatory action on Purkinje cells, and that the inhibitory pathway occurs via an inhibitory interneurone — a basket cell or a stellate cell. Direct stimulation of parallel fibres gives intracellular potentials closely resembling those produced by deep stimulation of mossy fibres. 3. As would be expected, direct stimulation of parallel fibres produces an EPSP with a latency 1 to 2 msec briefer than the IPSP. The IPSP has a duration usually in excess of 100 msec. The EPSP appears to be briefer, though its superposition on the IPSP greatly reduces its apparent duration. Neutralization of the IPSP by appropriate membrane polarization or by intracellular chloride injection reveals an EPSP duration of up to 50 msec. 4. The IPSP is typically affected by polarizing currents; reduced and even inverted by hyperpolarizing currents, and increased by depolarizing currents. The IPSP is converted to a depolarizing response by excess of intracellular chloride. It must therefore be generated by an increased ionic permeability of the inhibitory subsynaptic membrane, chloride ions being importantly concerned. 5. Often small irregular IPSPs can be observed occurring spontaneously, and they react to polarizing currents and to chloride injections in a manner identical to the evoked IPSPs. It is concluded that they are generated by the spontaneous discharges of basket cells. 6. A brief account is given of various spontaneous rhythmic responses of impaled Purkinje cells, and of the effect of synaptic inhibitory action upon them. 7. There is a general discussion of these findings in relation to the various neural pathways and neural mechanisms that have been postulated in the light of the preceding investigations.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 3 (1967), S. 81-94 
    ISSN: 1432-1106
    Keywords: Cerebellar inhibition ; Golgi cells ; Basket cells ; Purkinje cells ; Granule cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. There has been a comparative study of two kinds of inhibition in the cerebellar cortex: basket cell inhibition of Purkinje cells; and Golgi cell inhibition of granule cells. These inhibitory actions were assayed by the degree of inhibition of the potential waves that juxta-fastigial (J.F.) stimulation evoked in the granular or molecular layers: basket cell inhibition by the N1 wave generated by antidromic invasion of Purkinje cells; and Golgi cell inhibition of the N3 or P2 waves evoked by the mossy fibre volley in the molecular and granular layers respectively. 2. The Golgi cell inhibition produced by a parallel fibre volley (LOC stimulation) extended transversely for no more than 200 μ on either side of the narrow beam of the excited parallel fibres, whereas the spread of basket cell inhibition was much larger — to as far as 1 mm. 3. When activated by the on-beam LOC stimulation, the Golgi cell and the basket cell inhibition showed much the same threshold of the stimulation. The off-beam LOC stimulation produced only the basket cell inhibition which is in conformity with the different transverse distributions described in (2) above. 4. When evoked by J. F. or trans-folial (T. F.) stimulation, the Golgi cell inhibition had a much lower threshold than the basket cell inhibition. It is suggested that in part at least this is attributable to the direct synaptic connection from mossy fibres to Golgi cells. 5. The Golgi cell inhibition elicited by the LOC stimulation showed a relatively short time course, the maximum being attained by about 10 msec, after which there was an approximately exponential decrease so that the total duration was only about 100 msec. On the other hand, the basket cell inhibition had a much slower time course, maximum being attained at a latency of 20 to 40 msec, the total duration being even in excess of 200 msec. Suggestions are made with respect to the factors responsible for the slow time course of the basket cell inhibition.
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  • 6
    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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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 3 (1967), S. 58-80 
    ISSN: 1432-1106
    Keywords: Mossy fibres ; Cerebellar cortex ; Golgi cells ; Granule cells ; Purkinje cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Potential fields and unitary spikes in the cat cerebellar cortex were generated specifically by mossy fibre volleys and recorded by means of microelectrodes. The mossy fibres were excited by trans-folial (T. F.) stimulation which was compared with juxtafastigial (J.F.) stimulation. Both were conditioned by local stimuli of parallel fibres. 2. In the granular layer, an incoming mossy fibre volley evoked a small diphasic potential (P1 N1) and about 0.4 msec later a second negative wave (N2) due to the excitatory synaptic current generated by synapses of mossy fibres with granule cells and Golgi cells. In the typical configuration the N2 wave usually had a superimposed double spike potential, which is due to impulses discharged first by Golgi cells and then, about 0.5 msec later, by granule cells. 3. The transmission of impulses along the perpendicular axons of the granule cells and thence along the parallel fibres gave the fairly sharp positive potential (P2) in the granular layer, and simultaneously the negative wave (N3) in the molecular layer. The parallel fibre impulses, in turn, synaptically excited and so evoked local responses and action potentials in the dendrites of Purkinje and other cells, which aided in the production of the latter part of the N3 wave. 4. The impulses in the Purkinje cell dendrites propagate into the granular layer via the Purkinje cell somata and axons so producing the negative wave (N4) in the Purkinje and the granular layer. 5. The late and prolonged positive wave (P3) may be attributable to the deep active sources produced by postsynaptic inhibition of Purkinje cells and of granule cells by basket and Golgi cells respectively. 6. There has been good correlation between the physiological findings and the anatomical structures of the various types of cells and the synaptic connections, even to the synapses of mossy fibres on Golgi cell dendrites that have been recently described by HÁmori and SzentÁgothai.
    Type of Medium: Electronic Resource
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  • 8
    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.
    Type of Medium: Electronic Resource
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