Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-1106
    Keywords: Adaptation ; Vestibular ; Ocular ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Adaptability of the horizontal vestibulo-ocular reflex (HVOR) and the optokinetic response (OKR) was examined in alert albino rabbits during sustained runs lasting 5–12 h under four different stimulus conditions. (1) Sinusoidal rotation of the rabbit in darkness by 5 ° at 1/10 Hz, or (2) sinusoidal movement of a vertical slit light by 2.5 ° or 5 ° at 1/10 Hz around the optical axis of the stationary rabbit, affected the gain of neither the HVOR nor the OKR. (3) Combination of the stimulus as in (1) with the stationary slit light increased the gain of the HVOR gradually. A plateau at about 140% of the initial control was reached in 5 h. (4) Combination of the stimulus as in (1) with the slit light movement by 10 ° in phase with the turntable decreased the HVOR gain gradually, a plateau being obtained at about 70 % of the initial control in 5 h. Changes of the HVOR gain induced in conditions (3) and (4) were not frequency-specific and accompanied by no significant modification of either the gain or phase of the OKR or the linear property of HVOR-OKR interaction. A small but significant change of the HVOR phase was also detected under the condition (3) but not (4).
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 7 (1969), S. 214-230 
    ISSN: 1432-1106
    Keywords: Deiters ; Vestibular nerve ; EPSP ; Monosynaptic ; Disynaptic ; IPSP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Stimulation of the vestibular nerve induced EPSPs monosynaptically in 29% of cat's Deiters neurones sampled on the ipsilateral side. These EPSPs started with latencies of 0.6–1.0 msec, rose sharply with a summit time of 0.5 msec and decayed exponentially with a time constant of 0.9–1.7 msec. Then amplitudes were graded finely according to the intensity of the vestibular nerve stimulation, the maximal size being 5–10 mV. The unitary EPSPs, evoked by vestibular nerve stimulation at juxta-threshold intensity or appearing spontaneously, were as small as 0.2–0.3 mV in amplitude. Those neurones monosynaptically activated by vestibular nerve volleys were located in the ventral portion of the nucleus of Deiters, in agreement with histological data. The vestibular nerve impulses also produced delayed EPSPs with latencies of 1.0–1.8 msec, presumably disynaptically. They occurred in many Deiters neurones located not only ventrally but also dorsally. Even later EPSPs often were superposed on the monosynaptic EPSPs with latencies of 1.9–2.2 msec. There is evidence that they were caused by repetitive discharges in the vestibular nerve fibres which occur in response to single shock stimulation of the vestibular nerve. IPSPs were produced only polysynaptically in some Deiters neurones in association with the monosynaptic EPSPs.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 6 (1968), S. 247-264 
    ISSN: 1432-1106
    Keywords: Deiters neurones ; Disinhibition ; Cerebellum ; Cats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Following the stimulation of cerebellar cortex, a slow depolarization developed in the neurones which were impaled with microelectrodes in the dorsal portion of the nucleus of Deiters. Characteristically, it was produced bilaterally from a wide area of the culmen and, with double shock stimulation at brief intervals, showed a marked potentiation, often in association with a later depression. After repetitive stimulation of the cerebellar cortex the slow depolarization was prolonged for a period of many seconds. Even stimulation of the spinal cord caused similar depolarization. By intracellular injection of currents and ions, the depolarization was shown to be disinhibition, i. e., removal of background inhibition. Accordingly, it was confirmed that there was a steady production of IPSPs in dorsal Deiters neurones, which diminished during the phase of disinhibition. As the possible source of these background IPSPs, the Purkinje cell axons within the nucleus of Deiters were found to be discharging rhythmically at a rate of 20–90/sec, and in fact they were depressed very effectively after cerebellar stimulation. At the same time, volleys along Purkinje cell axons produced by a testing cerebellar stimulation also were diminished, indicating a depression in the excitability of Purkinje cells.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 12 (1971), S. 223-237 
    ISSN: 1432-1106
    Keywords: Deiters ; Purkinje Cell ; Mossy fibre ; Granule Cell ; IPSP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In anaesthetized cats, electric pulse stimuli were applied at various lateralities to the anterior lobe of the cerebellum. In dorsal Deiters neurones delayed IPSPs with latencies of 3–6 msec were evoked from the entire area of the culmen including the paravermis bilaterally. The delayed IPSPs had a summit time of about 2 msec and a duration of about 7 msec. They showed a marked temporal facilitation and subsequent depression with double shock stimulation. Corticovestibular fibers were penetrated within the nucleus of Deiters and showed delayed, labile responses to cortical stimulation, corresponding to the delayed IPSPs in Deiters neurones. During stimulation of the anterior lobe at any laterality, field potentials recorded in the cerebellar cortex further revealed that there was activation, presumably through axon collaterals of mossy fibers, of granule cells and subsequently of Purkinje cells in the vermal cortex. Cortical events exhibited a prominent temporal facilitation and subsequent depression, in parallel with that observed for the delayed IPSPs in Deiters neurones. The delayed IPSPs in Deiters neurones arising from a wide area of the cerebellar cortex thus were attributed to activation through mossy fiber-granule cell pathway of Purkinje cells of the corticovestibular projection.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 4 (1968), S. 310-320 
    ISSN: 1432-1106
    Keywords: Deiters neurones ; Cerebellum ; Inhibitory zone ; Cats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary By recording intracellularly from Deiters neurones of cats, there was a survey of those cerebellar areas that, when stimulated, produced inhibitory postsynaptic potentials (IPSPs) monosynaptically in Deiters neurones. The monosynaptic inhibitory area expanded longitudinally mainly along the ipsilateral vermal cortex of the anterior lobe. The ipsilateral cortex of the posterior lobe was also effective in inhibiting Deiters neurones though less prominently than the anterior lobe. The inhibitory fibers could be stimulated in the white matter of the cerebellum, predominantly in the ipsilateral side at rostral regions of nuclei fastigii and interpositus. It was further shown that the monosynaptic inhibition from the anterior and posterior lobes occurs chiefly in the dorsal portion of Deiters nucleus. Since in both the cerebellum and Deiters nucleus the spatial pattern of distribution of the inhibitory fibers conforms to that of the corticovestibular fibers as histologically defined, the experimental findings are in accord with the hypothesis that the cerebellar Purkinje cells are inhibitory in nature.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-1106
    Keywords: Axon reflex ; Deiters neurones ; Cerebellar afferents ; Cats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary When recording intracellularly from cat's Deiters neurones, stimulation of the anterior lobe of the cerebellar cortex produced excitatory postsynaptic potentials (EPSPs) monosynaptically, in addition to the inhibitory ones (IPSPs) that were identified previously as being produced via Purkinje cell axons. The EPSPs were induced bilaterally from a wide area of the anterior and posterior lobes of the cerebellum, in contrast to the IPSPs that were evoked only ipsilaterally, mainly from the vermal cortex. The latency of the EPSPs was slightly, but significantly, shorter than that of the IPSPs. The presynaptic impulses responsible for these EPSPs were represented by the discrete field potentials and also by unit spikes of individual fibres. The pathway for these EPSPs and presynaptic impulses was pursued by testing their interference, in the manner of impulse collision and refractoriness, with those induced from various spots within or outside the cerebellum. It is found that the excitatory fibres for Deiters neurones extend transversely, and probably longitudinally too, over the culmen and pass out of the cerebellum through cerebellar peduncles. The major portion of them appears to originate from the medulla and a minority from the spinal cord. It is postulated that cerebellar afferents from these structures have synapses with Deiters neurones via their collateral branches, through which a kind of axon reflex occurs to Deiters neurones during stimulation of the cerebellar cortex.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 18 (1973), S. 446-463 
    ISSN: 1432-1106
    Keywords: Cerebellum ; Vestibular ; Spinocerebellar ; Purkinje ; Deiters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The organization of the cerebellar, vestibular and spinal inputs to the lateral and medial vestibulospinal tract (LVST and MVST) cells was studied in anaesthetized rabbits. Synaptic actions of these inputs were determined by recording postsynaptic potentials intracellularly and also unit spike discharges extracellularly from a number of LVST and MVST cells. As reported previously in cats, inhibition was evoked very frequently from the vermal cortex of the cerebellar anterior lobe and less frequently from that of the posterior lobe. However, no such inhibition was derived from the flocculus. The cerebellar inhibition was exerted upon both LVST and MVST cells, whether they received monosynaptic activation from the primary vestibular afferents (second-order) or not and whether they conducted impulses fast or slowly. However, the inhibition was frequently absent in “slow” “second-order” MVST cells. The vast majority of LVST and MVST cells received an excitatory input from the spinocerebellar afferents ascending the funiculus posterolateralis. This input was particularly prominent from the upper cervical cord. The spinal excitation thus obtained occurred in close connection with the cerebellar inhibition. Hence, it appears that the cerebellar vermis receives the spinal signals that drive LVST and MVST cells and in turn sends out inhibitory signals to adjust the reflex activity in these cells.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1614-7456
    Keywords: Quadrupedal locomotion ; Gait pattern ; Adaptation ; Periodic perturbation ; Coupled oscillators ; Limb dynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract Quadrupeds can acquire new gait patterns with respect to environmental changes. Yanagihara et al. have demonstrated this adaptability by experiments on a decerebrate cat. These experiments indicate that quadrupeds gradually adapt to their environment by repeating locomotion in a steady environment, and that the acquired gait pattern is persistently memorized after the locomotion. Our research aims at formulating a mathematical model of these cats' behavior and constructing a quadrupedal walking robot to realize such adaptive behavior. To date, we have proposed a mathematical description of adaptation at the level of gait pattern generation using neural oscillators. In this paper, we extend it to take into account limb dynamics. We study how to design the interaction of the oscillator and limb dynamics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...