Evidence of a collateralized climbing fiber projection from the inferior olive to the flocculus and vestibular nuclei in rabbits

1981 ◽  
Vol 22 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Carey D. Balaban ◽  
Yasuo Kawaguchi ◽  
Eiju Watanabe
Keyword(s):  
Inferior Olive ◽  
Vestibular Nuclei ◽  
Climbing Fiber

scholarly journals Cerebellar and vestibular nuclear synapses in the inferior olive have distinct release kinetics and neurotransmitters

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Josef Turecek ◽  
Wade G Regehr
Keyword(s):  
Purkinje Cells ◽  
Inferior Olive ◽  
Release Kinetics ◽  
Vestibular Nuclei ◽  
Cerebellar Nuclei ◽  
Climbing Fiber ◽  
Inhibitory Input ◽  
Deep Cerebellar Nuclei

The inferior olive (IO) is composed of electrically-coupled neurons that make climbing fiber synapses onto Purkinje cells. Neurons in different IO subnuclei are inhibited by synapses with wide ranging release kinetics. Inhibition can be exclusively synchronous, asynchronous, or a mixture of both. Whether the same boutons, neurons or sources provide these kinetically distinct types of inhibition was not known. We find that in mice the deep cerebellar nuclei (DCN) and vestibular nuclei (VN) are two major sources of inhibition to the IO that are specialized to provide inhibitory input with distinct kinetics. DCN to IO synapses lack fast synaptotagmin isoforms, release neurotransmitter asynchronously, and are exclusively GABAergic. VN to IO synapses contain fast synaptotagmin isoforms, release neurotransmitter synchronously, and are mediated by combined GABAergic and glycinergic transmission. These findings indicate that VN and DCN inhibitory inputs to the IO are suited to control different aspects of IO activity.

scholarly journals Synaptic inputs to the inferior olive from cerebellar and vestibular nuclei have distinct release kinetics and neurotransmitters

2020 ◽  
Author(s):  
Josef Turecek ◽  
Wade G. Regehr
Keyword(s):  
Purkinje Cells ◽  
Inferior Olive ◽  
Release Kinetics ◽  
Vestibular Nuclei ◽  
Cerebellar Nuclei ◽  
Climbing Fiber ◽  
Inhibitory Input ◽  
Deep Cerebellar Nuclei ◽  
Synaptic Inputs

AbstractThe inferior olive (IO) is comprised of electrically-coupled neurons that make climbing fiber synapses onto Purkinje cells. Neurons in different IO subnuclei are inhibited by synapses with wide ranging release kinetics. Inhibition can be exclusively synchronous, asynchronous, or a mixture of both. Whether the same boutons, neurons or sources provide these kinetically distinct types of inhibition was not known. We find that the deep cerebellar nuclei (DCN) and vestibular nuclei (VN) are two major sources of inhibition to the IO that are specialized to provide inhibitory input with distinct kinetics. DCN to IO synapses lack fast synaptotagmin isoforms, release neurotransmitter asynchronously, and are exclusively GABAergic. VN to IO synapses contain fast synaptotagmin isoforms, release neurotransmitter synchronously, and are mediated by combined GABAergic and glycinergic transmission. These findings indicate that VN and DCN inhibitory inputs to the IO are suited to control different aspects of IO activity.

Vestibular Signals in the Parasolitary Nucleus

2000 ◽  
Vol 83 (6) ◽  
pp. 3559-3569 ◽  
Author(s):  
N. H. Barmack ◽  
V. Yakhnitsa
Keyword(s):  
Inferior Olive ◽  
Granule Cells ◽  
Vestibular Nucleus ◽  
Semicircular Canals ◽  
Longitudinal Axis ◽  
Vestibular Stimulation ◽  
Primary Afferents ◽  
Climbing Fiber ◽  
Large Sphere ◽  
Optimal Response

Vestibular primary afferents project to secondary vestibular neurons located in the vestibular complex. Vestibular primary afferents also project to the uvula-nodulus of the cerebellum where they terminate on granule cells. In this report we describe the physiological properties of neurons in a “new” vestibular nucleus, the parasolitary nucleus (Psol). This nucleus consists of 2,300 GABAergic neurons that project onto the ipsilateral inferior olive (β-nucleus and dorsomedial cell column) as well as the nucleus reticularis gigantocellularis. These olivary neurons are the exclusive source of vestibularly modulated climbing fiber inputs to the cerebellum. We recorded the activity of Psol neurons during natural vestibular stimulation in anesthetized rabbits. The rabbits were placed in a three-axis rate table at the center of a large sphere, permitting vestibular and optokinetic stimulation. We recorded from 74 neurons in the Psol and from 23 neurons in the regions bordering Psol. The activity of 72/74 Psol neurons and 4/23 non-Psol neurons was modulated by vestibular stimulation in either the pitch or roll planes but not the horizontal plane. Psol neurons responded in phase with ipsilateral side-down head position or velocity during sinusoidal stimulation. Approximately 80% of the recorded Psol neurons responded to static roll-tilt. The optimal response planes of evoked vestibular responses were inferred from measurement of null planes. Optimal response planes usually were aligned with the anatomical orientation of one of the two ipsilateral vertical semicircular canals. The frequency dependence of null plane measurements indicated a convergence of vestibular information from otoliths and semicircular canals. None of the recorded neurons evinced optokinetic sensitivity. These results are consistent with the view that Psol neurons provide the vestibular signals to the inferior olive that eventually reached the cerebellum in the form of modulated climbing fiber discharges. These signals provide information about spatial orientation about the longitudinal axis.

scholarly journals In Search of the Identity of the Cerebellar Climbing Fiber Transmitter: Immunocytochemical Studies in Rats

1993 ◽  
Vol 20 (S3) ◽  
pp. S36-S42 ◽  
Author(s):  
Zhang Nianhui ◽  
P. Ottersen Ole
Keyword(s):  
Amino Acids ◽  
Excitatory Amino Acids ◽  
Inferior Olive ◽  
Cell Layer ◽  
Climbing Fiber ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Homocysteic Acid ◽  
Immunocytochemical Studies

ABSTRACT:Quantitative immunogold cytochemistry at the electron microscopic level was used to assess the endogenous contents of glutamate, aspartate, homocysteic acid, and glutamine (a precursor of glutamate) in the cerebellar climbing fiber terminals. Of the three excitatory amino acids, only glutamate appeared to be enriched in these terminals. The climbing fiber terminals also displayed immunoreactivity for glutamine. The level of aspartate immunoreactivity was far higher in the nerve cell bodies in the inferior olive than in their terminals in the cerebellar cortex. Homocysteic acid immunolabelling was concentrated in glial cells including the Golgi epithelial cells in the Purkinje cell layer. Our immunocytochemical data indicate that glutamate is a more likely climbing fiber transmitter than aspartate and homocysteic acid.

scholarly journals Specificity of Inferior Olive Response to Stimulus Timing

2008 ◽  
Vol 100 (3) ◽  
pp. 1557-1561 ◽  
Author(s):  
T. Liu ◽  
D. Xu ◽  
J. Ashe ◽  
K. Bushara
Keyword(s):  
Cognitive Processes ◽  
Animal Studies ◽  
Inferior Olive ◽  
Sole Source ◽  
Climbing Fiber ◽  
Perceptual Task ◽  
Fiber System ◽  
Stimulus Timing ◽  
Rhythmic Firing ◽  
Firing Properties

The inferior olive is the sole source of the climbing fiber system, one of the two major afferent systems of the cerebellum; however, its exact role remains unknown. A longstanding hypothesis is that the inferior olive with its unique intrinsic rhythmic firing properties mediates motor timing. However, direct evidence linking the inferior olive to timing behavior has been difficult to demonstrate in animal or human studies likely due to the inhibition of inferior olive responses by self-produced movement. Here we used event-related functional magnetic resonance imaging (fMRI) and a perceptual task that dissociates the temporal from nontemporal attributes of sensory input. Subjects were asked to attend to rhythmically occurring identical visual stimuli and to detect a change in their timing, spatial orientation, or color. Inferior olive activation was seen only when perceiving a change in stimulus timing. These results are consistent with animal studies demonstrating that the inferior olive is especially sensitive to “unexpected” sensory events and further provide evidence supporting the specificity of the inferior olive response to stimulus timing. The results are consistent with the view that the inferior olive and the climbing fiber system mediate the encoding of temporal information required for both motor and nonmotor cognitive processes.

Neurons of the medial terminal accessory optic nucleus of the rat are poorly collateralized

1989 ◽  
Vol 2 (3) ◽  
pp. 269-273 ◽  
Author(s):  
R. J. Clarke ◽  
R. A. Giolli ◽  
R. H. Blanks ◽  
Y. Torigoe ◽  
J. H. Fallon
Keyword(s):  
Optokinetic Nystagmus ◽  
Inferior Olive ◽  
Previous Analysis ◽  
Optic Tract ◽  
Vestibular Nuclei ◽  
The Other ◽  
Projection Neurons ◽  
Double Labeling ◽  
Cell Counts ◽  
Brainstem Nuclei

AbstractThe vast majority of neurons of the rat medial terminal nucleus (MTN) project to the nucleus of the optic tract (NOT), but the MTN also projects to a lesser degree upon a number of other brainstem nuclei controlling optokinetic nystagmus. Because of the diversity of targets of the MTN, it is possible that individual neurons have branched axons that project to two or more brainstem nuclei. The possibility that axons of MTN-NOT neurons collateralize to innervate other MTN targets is examined in the rat with the fluorescent, double-labeling, retrograde tracer technique. Fluoro-Gold was injected into the NOT while Fast Blue was simultaneously injected into each of five other known targets of the MTN: the supraoculomotor-periaqueductal gray; the dorsal cap of the inferior olive; the visual tegmental relay zone; the dorsolateral nucleus of the basal pons; and the superior/lateral vestibular nuclei. Brainstem sections were processed for fluorescence microscopy and the MTN was examined for single- and double-labeled neurons. Results show that virtually all neurons of the MTN (>97.5%), together with neurons in the visual tegmental relay zone immediately surrounding the MTNd, are single-labeled in all paired injections involving the NOT and the other target nuclei. It was found that about 69% of MTN neurons project exclusively to the NOT, 5–10% project to each one of the other nuclei, and 3% of MTN neurons project to more than one target. Based upon cell counts from the fluorescent material, and previous analysis of Nissl-stained serial sections, the findings show that virtually all MTN neurons are projection neurons. It was concluded that the MTN is comprised of independent projection systems, possibly involved in different aspects of generating optokinetic nystagmus.

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