The cerebellar projection from the lateral reticular nucleus as studied with retrograde transport of horseradish peroxidase (original) (raw)

The cerebellar corticonuclear and nucleocortical projections in the cat as studied with anterograde and retrograde transport of horseradish peroxidase

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.

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.

A horseradish peroxidase study of the projections from the lateral reticular nucleus to the cerebellum in the rat

Anatomy and Embryology, 1982

The projection from the lateral reticular nucleus (LRN) to the cerebellar cortex was studied in the rat by utilizing the retrograde transport of horseradish peroxidase (HRP). In order to study the topographic features of this projection, small amounts of HRP were injected into various sites in the cerebellar cortex. The results demonstrated that the caudal lobules of the anterior lobe vermis tend to receive afferents from the medial LRN and the rostral lobules of the vermis receive afferents from more laterally situated cells. Lobules IV and V receive inputs primarily from the magnocellular division of the LRN of both the ventromedial and dorsolateral parts of the LRN, while lobules II and III receive inputs mainly from cells which lie in the border area between the parvocellular and magnocellular division of the ventromedial part. Following injections within various areas of the posterior lobe vermis, the results indicated that lobule VIII receives the most abundant projection from the LRN and that the cells of origin are present within the parvocellular and the adjacent part of the magnocellular division throughout the rostrocaudal extent of the LRN. Following injections within lobules VI and VII, few labelled cells were found and they tended to lie within the rostral two-thirds of the magnocellular division. Little or no projection from the LRN to lobule IX was evident. The hemispheres were found to receive a modest projection from the dorsal aspect of the LRN. The projection to lobulus simplex originates mainly from the caudal two-thirds of the magnocellular division, while the projection to the ansiform and paramedian lobules originates mainly from the dorsal aspect of the rostral two-thirds of the magnocellular division. Finally, there appears to be extensive overlapping of the origins of all three projections to the cerebellar cortex studied, and this occurs within the central area of the magnocellular division throughout the rostrocaudal extent of the LRN.

The cerebellar nucleo-olivary projection in the cat

Anatomy and Embryology, 1981

The crossed cerebello-olivary projection in the cat was studied by means of retrograde transport of HRP. The cerebello-olivary connection is organized according to a zonal pattern similar to that of the olivocerebellar projection. However, some labelled neurons are in addition found in cerebellar nuclear areas adjacent to a nuclear zone sending its fibres to the corresponding olivary region. This observation indicates that there is a certain degree of overlapping between the different nuclear zones. The cerebello-olivary fibres from the fastigial nucleus appear to be more widely distributed than those from the other cerebellar nuclei. Nuclear neurons of all sizes project to the inferior olive, but the majority of the cells are medium sized. The findings are discussed and related to previous studies on the cerebelloolivary connection.

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 afferent projections from the perihypoglossal nuclei: An experimental study with the method of retrograde axonal transport of horseradish peroxidase

Experimental Brain Research, 1978

Details of cerebellar afferent projections from the perihypoglossal nuclei were studied in the cat by means of retrograde axonal transport of horseradish peroxidase (HRP). Labeled cells were observed bilaterally (with a preponderance ipsilaterally) in nuclei intercalatus and praepositus hypoglossi following injections in various folia of the entire vermis, paraflocculus, flocculus, fastigial nucleus, and the nucleus interpositus anterior and posterior. Relatively high densities of labeled cells were found in nucleus intercalatus following injections in the anterior part of the vermis, whereas labeled cells in nucleus praepositus hypoglossi were found more frequently following injections in the posterior part of the vermis. Labeled cells in the nucleus of Roller were found only following injections in the anterior lobe vermis, posterior vermal lobules VI and VII, in the flocculus and in the nucleus interpositus anterior. No labeled cells could be detected in the three subdivisions of the perihypoglossal nuclei following HRP injections in crus I, crus II, paramedian lobule, and lateral cerebellar nucleus. The distribution of the HRP positive cells indicated the presence of a topographically organized projection from certain regions of the perihypoglossal nuclei to different parts of the cerebellum. The afferent and efferent connections of the perihypoglossal nuclei in relation to a functional role in eye and head movements are discussed.

The cerebellar corticovestibular projection in the cat as studied with retrograde transport of horseradish peroxidase

Anatomy and Embryology, 1983

The cerebellar corticovestibular projection in the cat was studied by means of retrograde transport of HRP. After injections confined to the vestibular nuclei retrogradely labelled Purkinje cells were found ipsilaterally in vermal lobules I through X, crus I, the ventral paraflocculus and flocculus. The neurons projecting to the vestibular nuclei are located in all parts of the cerebellar folia (bottom, side and top). Most of the vestibular projecting Purkinje cells are located within a sagittal band (corresponding to Voogd's B zone) in the lateral vermis. In some of our cats the width of this band exceeds 1 mm in lobule I, 800 gm in lobule II and 1.5 mm in lobule V. However, the sagittal band is not sharply demarcated, and some retrogradely labelled Purkinje cells were present almost in the midline while others were located more than 4 mm lateral to this. The findings are discussed with special emphasis on the cerebellar sagittal zonal arrangement and related to previous studies on the cerebellar corticovestibular projection.

The Projections of the Lateral Reticular Nucleus to the Deep Cerebellar Nuclei. An Experimental Analysis in the Rat

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.

Cerebellar connections of the ventral lateral geniculate nucleus in the rat

Anatomy and Embryology, 1992

The connections between the deep cerebellar nuclei and the ventral lateral geniculate nucleus (LGv) were investigated in rats using orthograde and retrograde transport of horseradish peroxidase. Following injections into the deep cerebellar nuclei there was orthograde transport to the contralateral medial LGv and adjacent zona incerta. Injections restricted to LGv consistently labelled a small cluster of cells in the contralateral posterior interposed nucleus. Injections into regions surrounding LGv produced distinctively different patterns of orthograde and retrograde labelling.