Library

X
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
    Electronic Resource
    Electronic Resource
    Presynaptic impulses in the abducens nucleus and their relation to postsynaptic potentials in motoneurons during vestibular nystagmus (1977)
    Springer
    Experimental brain research 27 (1977), S. 355-376 
    Details
    ISSN: 1432-1106
    Keywords: Vestibular nystagmus ; Abducens motoneuron ; Presynaptic impulse ; Vestibular neuron ; Burst neuron
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Unit spikes of axons projecting to the abducens nucleus and responding to horizontal rotation of the head were recorded within the cat abducens nucleus. Their discharge pattern related to vestibular nystagmus was investigated with reference to PSP changes of abducens motoneurons as monitored by the field potentials in the nucleus. There were four groups of presynaptic axons whose activity was tightly related to motoneuronal PSPs. 2. The first and second groups of axons were activated mono- and disynaptically from the contralateral labyrinth, respectively, and fired in phase with abducens nerve discharges. Their tonic activity during the slow excitatory phase of motoneurons was abruptly suppressed at the onset of positive field potential (motoneuronal hyperpolarization). The disynaptically activated axons exhibited burst-tonic discharges at the quick excitatory phase and steep increases in their discharge frequency were synchronous with the onset of negative field potential (motoneuronal depolarization). 3. The third group was activated monosynaptically from the ipsilateral labyrinth and fired in phase with the silent period of the abducens nerve. Their tonic activity during the slow inhibitory phase of motoneurons was abruptly silenced at the onset of negative field potential. At the quick inhibitory phase they tended to begin firing slightly later than the onset of positive field potential. 4. The fourth group exhibited high frequency burst discharges at the quick inhibitory phase of motoneurons. Steep increases in discharge frequency occurred synchronously with the onset of the positive field potential. These axons were silent during the slow inhibitory phase of motoneurons. 5. The characteristic time course of PSPs in abducens motoneurons during vestibular nystagmus was well explained by synaptic actions of these four groups of presynaptic axon on motoneurons. The origin of each group of axon was discussed in view of their responses to electric stimulation of the vestibular nerve.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235510
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Cervical effects on abducens motoneurons and their interaction with vestibulo-ocular reflex (1973)
    Springer
    Experimental brain research 18 (1973), S. 512-530 
    Details
    ISSN: 1432-1106
    Keywords: Cervical afferents ; Abducens motoneuron ; Interneuron ; Vestibular nuclei
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of neck afferents on abducens motoneurons and their interaction with the vestibulo-abducens reflex were examined in chloraloseanesthetized or unanesthetized, decerebrate cats. The test reflex elicited in the abducens nerve by stimulation of the contralateral vestibular nerve was inhibited by contralateral and facilitated by ipsilateral cervical dorsal root or neck joint stimulation. These reciprocal effects were obtained by stimulation at the level of C2 and C3, but not from C5 or lower. Contralateral and ipsilateral cervical stimulation induced IPSPs and EPSPs, respectively, in abducens motoneurons. The latencies were 2.8–6.0 msec for the IPSP and 2.8–5.3 msec for the EPSP after stimulation of the dorsal root. The labyrinthine-induced disynaptic IPSP or EPSP was facilitated by conditioning stimulation of the contralateral and ipsilateral cervical dorsal root, respectively. It is thus postulated that the cervico-abducens and vestibuloabducens reflex pathways converge upon common inhibitory or excitatory interneurons in the vestibular nuclie. Labyrinthine- and cervical-induced responses of the presumed interneurons in the vestibular nuclei or those of their axons recorded in the abducens nuclie were consistent with the above view. Lesion experiments in the brain stem indicated that afferent volleys from the neck joint ascend ipsilaterally in the spinal cord, cross to the contralateral side in the brain stem, and eventually project to the vestibular nuclei, thus interacting with the vestibulo-ocular reflex activity. A possible functional role of the cervical effects on the ocular motoneuron was briefly discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234135
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...