Relationship of inferior olive-climbing fibers to p,p′-DDT-induced myoclonus in rats

1981 ◽  
Vol 24 (1) ◽  
pp. 103-108 ◽  
Author(s):  
E. Chung Hwang ◽  
A. Plaitakis ◽  
I. Magnussen ◽  
M.H. Van Woert
Keyword(s):  
Inferior Olive ◽  
Climbing Fibers ◽  
Relationship Of

Motor Coding in Floccular Climbing Fibers

2006 ◽  
Vol 95 (4) ◽  
pp. 2342-2351 ◽  
Author(s):  
Beerend Winkelman ◽  
Maarten Frens
Keyword(s):  
Visual Motion ◽  
Inferior Olive ◽  
Motor Behavior ◽  
Climbing Fibers ◽  
Retinal Slip ◽  
Motor Component ◽  
Prepositus Hypoglossi ◽  
Sensorimotor Information ◽  
Sensory Encoding ◽  
Oculomotor Learning

The climbing fibers (CFs) that project from the dorsal cap of the inferior olive (IO) to the flocculus of the cerebellar cortex have been reported to be purely sensory, encoding “retinal slip.” However, a clear oculomotor projection from the nucleus prepositus hypoglossi (NPH) to the IO has been shown. We therefore studied the sensorimotor information that is present in the CF signal. We presented rabbits with visual motion noise stimuli to break up the tight relation between instantaneous retinal slip and eye movement. Strikingly, the information about the motor behavior in the CF signal more than doubled that of the sensory component and was time-locked more tightly. The contribution of oculomotor signals was independently confirmed by analysis of spontaneous eye movements in the absence of visual input. The motor component of the CF code is essential to distinguish unexpected slip from self-generated slip, which is a prerequisite for proper oculomotor learning.

A Functionally Important Feature of the Distribution of the Olivo–Cerebellar Climbing Fibers

1974 ◽  
Vol 52 (6) ◽  
pp. 1212-1217 ◽  
Author(s):  
J. Courville ◽  
F. Faraco-Cantin ◽  
N. Diakiw
Keyword(s):  
Cerebellar Cortex ◽  
Central Region ◽  
Inferior Olive ◽  
Molecular Layer ◽  
Climbing Fibers ◽  
Striking Feature ◽  
Contralateral Projection

The olivo–cerebellar projection has been demonstrated by injections of small volumes of tritiated l-leucine in the inferior olive. A strictly contralateral projection to the cerebellar cortex has been found. Labelling of terminal fibers in the molecular layer is restricted to the paravermian and lateral regions of cortex after an injection of the central region of the olive. The distribution presents a very striking feature: the label is distributed along sagittal bands about 0.4 mm wide interrupted by empty spaces of the same width. It is suggested that an extra-olivary source provides the climbing fibers distributed in these spaces.

Developmental Changes in Evoked Purkinje Cell Complex Spike Responses

2003 ◽  
Vol 90 (4) ◽  
pp. 2349-2357 ◽  
Author(s):  
Daniel A. Nicholson ◽  
John H. Freeman
Keyword(s):  
Motor Learning ◽  
Purkinje Cell ◽  
Inferior Olive ◽  
Cell Complex ◽  
Climbing Fibers ◽  
Somatosensory Stimulation ◽  
Complex Spike ◽  
Long Latency ◽  
Inhibitory Feedback ◽  
Complex Spikes

The development of synaptic interconnections between the cerebellum and inferior olive, the sole source of climbing fibers, could contribute to the ontogeny of certain forms of motor learning (e.g., eyeblink conditioning). Purkinje cell complex spikes are produced exclusively by climbing fibers and exhibit short- and long-latency activity in response to somatosensory stimulation. Previous studies have demonstrated that evoked short- and long-latency complex spikes generally occur on separate trials and that this response segregation is regulated by inhibitory feedback to the inferior olive. The present experiment tested the hypothesis that complex spikes evoked by periorbital stimulation are regulated by inhibitory feedback from the cerebellum and that this feedback develops between postnatal days (PND) 17 and 24. Recordings from individual Purkinje cell complex spikes in urethan-anesthetized rats indicated that the segregation of short- and long-latency evoked complex spike activity emerges between PND17 and PND24. In addition, infusion of picrotoxin, a GABAA-receptor antagonist, into the inferior olive abolished the response pattern segregation in PND24 rats, producing evoked complex spike response patterns similar to those characteristic of younger rats. These data support the view that cerebellar feedback to the inferior olive, which is exclusively inhibitory, undergoes substantial changes in the same developmental time window in which certain forms of motor learning emerge.

Effects of microlesions of dorsal cap of inferior olive of rabbits on optokinetic and vestibuloocular reflexes

1980 ◽  
Vol 43 (1) ◽  
pp. 182-206 ◽  
Author(s):  
N. H. Barmack ◽  
J. I. Simpson
Keyword(s):  
Eye Movements ◽  
Inferior Olive ◽  
Field Potential ◽  
Climbing Fibers ◽  
Optokinetic Stimulation ◽  
Low Velocity ◽  
Retinal Slip ◽  
Electrolytic Lesions ◽  
Contralateral Eye ◽  
Velocity Bias

1. Discrete, unilateral, electrolytic lesions of the dorsal cap of the inferior olive were made in rabbits in an attempt to assess the effect on eye movements of removal of a visual climbing fiber input to the fluocculus. The position of the lesioning electrode within the dorsal cap was adjusted on the basis of the field potential evoked by flash stimulation of the contralateral eye. 2. Electrophysiological and anatomical evidence confirmed that the microlesions of the dorsal cap destroyed 10-80% of olivary cells, but cause only slight damage to the olivocerebellar pathway originating from the contralateral dorsal cap. 3. The immediate effect of the microlesions was a spontaneous, conjugate drift of the eyes to the side contralateral to the lesion. The effects of the microlesions on eye movements were further examined using reflexes evoked by vestibular and optokinetic stimulation. 4. Postoperatively, the vestibuloocular reflex (VOR) gain was not modified, but there was a marked VOR velocity bias to the contralateral side. This velocity bias was most pronounced at low stimulus frequencies (0.02-0.05 Hz, +/- 10 degrees) and was minimal at stimulus frequencies above 0.5 Hz. 5. Monocular, sinusoidal optokinetic stimulation with a large contrast-rich visual target evokes, in normal rabbits, a conjugate asymmetric following response with a higher eye velocity for target movement from posterior to anterior. Following damage to the dorsal cap, the asymmetry of this optokinetic reflex was reversed when the target was presented to the eye contralateral to the lesion. With monocular, constant-velocity optokinetic stimulation delivered to the contralateral eye, the optokinetic gain for movement in the posterior to anterior direction was decreased. 6. These data suggest that visual climbing fibers are part of a feedback loop that reduces retinal slip of low velocity. The relatively low discharge rate of climbing fibers would seem appropriate to ecode continuously retinal slip of low velocity and to influence low-velocity eye movements.

scholarly journals Time and Frequency Characteristics of Purkinje Cell Complex Spikes in the Awake Monkey Performing a Nonperiodic Task

2008 ◽  
Vol 100 (2) ◽  
pp. 1032-1040 ◽  
Author(s):  
Shahin Hakimian ◽  
Scott A. Norris ◽  
Bradley Greger ◽  
Jeffrey G. Keating ◽  
Charles H. Anderson ◽  
...  
Keyword(s):  
Purkinje Cell ◽  
Refractory Period ◽  
Inferior Olive ◽  
Frequency Characteristics ◽  
Climbing Fibers ◽  
Cerebellar Hemisphere ◽  
Direct Test ◽  
Relative Refractory Period ◽  
Periodic Signals ◽  
Complex Spikes

A number of studies have been interpreted to support the view that the inferior olive climbing fibers send periodic signals to the cerebellum to time and pace behavior. In a direct test of this hypothesis in macaques performing nonperiodic tasks, we analyzed continuous recordings of complex spikes from the lateral cerebellar hemisphere. We found no periodicity outside of a 100-ms relative refractory period.

Climbing fibers in mouse cerebellum co-cultured with inferior olive

1983 ◽  
Vol 271 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Nathan K. Blank ◽  
Fredrick J. Seil ◽  
Arnold L. Leiman
Keyword(s):  
Inferior Olive ◽  
Climbing Fibers ◽  
Mouse Cerebellum

Afferent sources to the inferior olive and distribution of the olivocerebellar climbing fibers in cyprinids

2008 ◽  
Vol 507 (3) ◽  
pp. 1409-1427 ◽  
Author(s):  
Hao-Gang Xue ◽  
Chun-Ying Yang ◽  
Naoyuki Yamamoto
Keyword(s):  
Inferior Olive ◽  
Climbing Fibers

scholarly journals Association Between Dendritic Lamellar Bodies and Complex Spike Synchrony in the Olivocerebellar System

1997 ◽  
Vol 77 (4) ◽  
pp. 1747-1758 ◽  
Author(s):  
C. I. De Zeeuw ◽  
S.K.E. Koekkoek ◽  
D.R.W. Wylie ◽  
J. I. Simpson
Keyword(s):  
Purkinje Cell ◽  
Gap Junctions ◽  
Purkinje Cells ◽  
Inferior Olive ◽  
Cerebellar Nuclei ◽  
Climbing Fibers ◽  
Lamellar Bodies ◽  
Spike Synchrony ◽  
Complex Spike ◽  
Simple Spike

De Zeeuw, C. I., S.K.E. Koekkoek, D.R.W. Wylie, and J. I. Simpson. Association between dendritic lamellar bodies and complex spike synchrony in the olivocerebellar system. J. Neurophysiol. 77: 1747–1758, 1997. Dendritic lamellar bodies have been reported to be associated with dendrodendritic gap junctions. In the present study we investigated this association at both the morphological and electrophysiological level in the olivocerebellar system. Because cerebellar GABAergic terminals are apposed to olivary dendrites coupled by gap junctions, and because lesions of cerebellar nuclei influence the coupling between neurons in the inferior olive, we postulated that if lamellar bodies and gap junctions are related, then the densities of both structures will change together when the cerebellar input is removed. Lesions of the cerebellar nuclei in rats and rabbits resulted in a reduction of the density of lamellar bodies, the number of lamellae per lamellar body, and the density of gap junctions in the inferior olive, whereas the number of olivary neurons was not significantly reduced. The association between lamellar bodies and electrotonic coupling was evaluated electrophysiologically in alert rabbits by comparing the occurrence of complex spike synchrony in different Purkinje cell zones of the flocculus that receive their climbing fibers from olivary subnuclei with different densities of lamellar bodies. The complex spike synchrony of Purkinje cell pairs, that receive their climbing fibers from an olivary subnucleus with a high density of lamellar bodies, was significantly higher than that of Purkinje cells, that receive their climbing fibers from a subnucleus with a low density of lamellar bodies. To investigate whether the complex spike synchrony is related to a possible synchrony between simple spikes, we recorded simultaneously the complex spike and simple spike responses of Purkinje cell pairs during natural visual stimulation. Synchronous simple spike responses did occur, and this synchrony tended to increase as the synchrony between the complex spikes increased. This relation raises the possibility that synchronously activated climbing fibers evoke their effects in part via the simple spike response of Purkinje cells. The present results indicate that dendritic lamellar bodies and dendrodendritic gap junctions can be downregulated concomitantly, and that the density of lamellar bodies in different olivary subdivisions is correlated with the degree of synchrony of their climbing fiber activity. Therefore these data support the hypothesis that dendritic lamellar bodies can be associated with dendrodendritic gap junctions. Considering that the density of dedritic lamellar bodies in the inferior olive is higher than in any other area of the brain, this conclusion implies that electrotonic coupling is important for the function of the olivocerebellar system.

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