The cerebellar nucleo-olivary projection in the cat (original) (raw)
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Cerebellar cortical and nuclear afferents from the Edinger-Westphal nucleus in the cat
Anatomy and Embryology, 1988
The cerebellar projection from the Edinger-Westphal nucleus was studied in the cat by means of retrograde transport of the wheat germ agglutinin-horseradish peroxidase complex. The present findings give evidence that the focculus is the main terminal area. However, small tracer implants and injections into various parts of the cerebellar nuclei and cortex revealed projections also to the fastigial and interposed nuclei and to most parts of the anterior and posterior lobe cortices. The projecting neurons are small and located bilaterally throughout the Edinger-Westphal nucleus. No topical differences between the projections to different parts of the cerebellum were found.
Cerebellar nuclear afferents from the lateral reticular nucleus in the cat
Brain Research, 1983
Cerebellar afferent fibers were anterogradely stained throughout their length after injections of horseradish peroxidase labeled wheat germ agglutinin in the lateral reticular nucleus in cats. Most fibers ascended through the ipsilateral restiform body, but a few fibers ran on the contralateral side. Some anterogradely stained fibers crossed the midline in cerebellum. Terminal fibers were present in the granular layer and in the cerebellar nuclei. Plexuses of nuclear terminal fibers were found in the ipsilateral interposed and dentate nuclei and were dense in the former. A smaller number of presumably terminal fibers were observed in the ipsilateral fastigial nucleus and in the contralateral cerebellar nuclei. The findings give further evidence for the lateral reticular nucleus being an important source of cerebellar nuclear afferents.
Anatomy and Embryology, 1979
The cerebellar corticonuclear and nucleocortical connections of lobulus simplex, crus I and II in the cat were studied by means of anterograde and retrograde transport of HRP. Previous experimental studies give evidence that the cortex of the cerebellar hemisphere in a lateromedial direction can be subdivided into five longitudinal zones. These are recognized as zones D2, D1, C3, C2 and C1. Our observations indicate that each cortical zone has its own field of termination in the cerebellar nuclei, and that these nuclear fields are similar to those receiving afferents from the corresponding zones within the paramedian lobule (Dietrichs and Walberg, 1979). The Purkinje axons from each folium terminate from medial to lateral along a continuous band which loops through the cerebellar nuclei from the ventromedial part of nucleus interpositus posterior to the dorsolateral part of the same nucleus, from where it proceeds into the lateral part of nucleus interpositus anterior and the transition area between nucleus interpositus anterior and the dentate nucleus, to end within the latter. In addition to this arrangement there is a rostrocaudal organization within the hemispheral cortex so that the nuclear bands receiving Purkinje axons from the rostral folia (lobulus simplex) are situated slightly ventral to those receiving terminal fibres from the middle folia (crus I), which again are situated ventral to the terminal bands for the caudal folia (crus II). The nucleocortical projection shows largely the same zonal arrangement as the corticonuclear, but labelled nuclear neurons are in some cases found bilaterally within the fastigial nucleus. This nucleus does not receive Purkinje axons from lobulus simplex, crus I and crus II. Offprint requests to.
Anatomy and Embryology, 1979
The cerebellar projection from the lateral reticular nucleus (NRL) was studied in cats by means of retrograde axonal transport of horseradish peroxidase (the projection to the paramedian lobule was not included, see Brodal, 1975, for afferents to this cortical region). The entire cerebellar cortex and all cerebellar nuclei receive fibres from the NRL. The strongest connection is with the anterior lobe and lobulus VIIIB of the posterior lobe vermis. As concerns the anterior lobe the observations confirm the previous finding by Brodal (1975) that there is a clearcut topical pattern in the nuclear projection to this part of the cerebellum. The observations furthermore show that crus II is the only cerebellar region devoid of fibres from the subtrigeminal part of the NRL. The cerebellar projection from the NRL is bilateral with a heavy ipsilateral preponderance. The large majority of the labeled cells within the NRL are of the small category (< 25 ~tm in size). This and the other findings are discussed in relation to previous studies on ,the efferent and afferent connections of the nucleus.
European Journal of Neuroscience, 1995
The extent to which the cells of origin of the cerebellar nucleocortical pathway are immunopositive for y-aminobutyric acid (GABA) was investigated in four cats using retrograde labelling of nucleocortical neurons in combination with immunocytochemistry. Neurons were retrogradely labelled by injection of fluorescent (coumarin)-tagged latex microspheres into the c2 zone in the rostral part of the paramedian lobule. The zone was identified electrophysiologically by the characteristics of the climbing fibre responses evoked on the cerebellar surface by percutaneous stimulation applied to the left and right forepaws in pentobarbitoneanaesthetized animals. Sections of the cerebellum containing the retrogradely labelled neurons were processed for GABA immunocytochemistty using a fluorescent (rhodamine)-tagged immunoglobulin. When viewed with epifluorescence microscopy and appropriate filter blocks the retrogradely labelled nucleocortical neurons could be visualized in the same sections as the GABA-immunopositive neurons. Almost all of a total of 254 labelled nucleocortical neurons were located in nucleus interpositus posterior, where a total of 71 1 GABAergic neurons were also found. None of these cells contained coumarin-tagged beads and displayed immunoreactivity for GABA (i.e. none was double-labelled). When compared by area of their cell body, the nucleocortical and GABAimmunopositive neurons appeared to form two partially overlapping populations. The mean cell area of the nucleocortical neurons was 620 ? 233 pm2 (SD), whereas the GABA-immunopositive neurons were much smaller, with a mean cell area of 220 z 115 pm2. The results suggest that GABA does not play a major role in the nucleocortical pathway to the c2 zone of the rostral paramedian lobule of the cat cerebellum.
European Journal of Neuroscience, 1996
The projections of the lateral reticular nucleus (LRN) to the cerebellar nuclei were studied using the retrograde axonal transport of tetramethyl rhodamine dextran amine (10% solution in 0.01 M neutral phosphate buffer) in 19 adult Wistar strain rats. The cerebellar nuclei receive topographically organized projections from the LRN. The projections are bilateral with an ipsilateral predominance and they are symmetrical. The contralateral component is progressively larger for projections to the nuclei interpositalis, to the nucleus lateralis and to the nucleus medialis. The projections to the various cerebellar nuclei arise from rostrocaudally oriented columns of neurons located in different (partly overlapping) areas of the magnocellular division of the LRN. The nucleus lateralis receives terminals from the dorsomedial area (mainly from the rostra1 level of the LRN), the nuclei interpositalis from the dorsolateral area (mainly from the central level) and the nucleus medialis from the intermedioventral area (mainly from the caudal level). Afferent fibres from the small subtrigeminal division were traced to the three cerebellar nuclei and from the parvocellular division to the nuclei interpositalis and medialis. The density of the projections from the LRN to the nuclei interpositalis increases progressively with the shift of the terminal field from the rostrolateral to the caudomedial part of the nucleus. The projections to the nucleus lateralis reach principally the dorsolateral hump, whereas only a few neurons project to the other divisions (parvo-and magnocellular). The projections to the various regions of the nucleus medialis show different densities. The highest density was found for projections to the caudal part, in particular to the dorsolateral protuberance and to the ventrolateral area of the middle division. Conversely, a low density of projections was found for the other areas of the middle division. The regions of the magnocellular division of the LRN which project to the nuclei lateralis (and are thus related to the cerebral cortex), interpositalis (related to the red nucleus) and medialis (related to the spinal cord) also receive afferent terminals from the cerebral cortex, the red nucleus and the spinal cord respectively, in addition to various afferent inputs. Thus, each of these areas is apparently concerned with integrating some spinal and supraspinal information in reverberating circuits.