Summary
The retrograde labeling of neurons in the deep cerebellar nuclei with horseradish peroxidase was used to compare the morphological characteristics of neurons in the dentate and interposed nuclei projecting in the cerebellothalamic, cerebello-olivary, and cerebellar nucleocortical pathways. The results from these studies demonstrated that cerebellothalamic and nucleocortical projections from the dentate and interposed nuclei originate from similar populations of spindle- and multipolar-shaped neurons with somal diameters throughout the range of cells present in the deep nuclei. However, only spindle-shaped neurons with somal diameters of 9–15 microns project in the cerebello-olivary pathway. From these anatomical studies, it was concluded that some of the neurons in the dentate and interposed nuclei which project to the thalamus, inferior olive, and cerebellar cortex have similar morphological characteristics. Electrophysiological experiments were carried out to investigate whether or not some of these neurons project to all three sites via axon collaterals. From stimulus sites in the thalamus, inferior olive, and cerebellar cortex, numerous neurons were antidromically activated in the cerebellar nuclei. Collision experiments between these antidromic responses confirmed that single neurons projected to all three of these sites. These studies therefore demonstrate that the axons of some neurons in the dentate and interposed nuclei have collateral branches in both the ascending and descending limbs of the brachium conjunctivum as well as in the cerebellar nucleocortical pathway. Functional implications of the collateral branching of cerebellar efferent projections are discussed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Allen, G.I., Tsukahara, N.: Cerebrocerebellar communication systems. Physiol. Rev. 54, 957–1006 (1974)
Bantli, H., Bloedel, J.R.: Monosynaptic activation of a direct reticulo-spinal pathway by the dentate nucleus. Pflügers Arch. ges. Physiol. 257, 237–242 (1975)
Bantli, H., Bloedel, J.R.: Characteristics of the output from the dentate nucleus to spinal neurons via pathways which do not involve the primary sensorimotor cortex. Exp. Brain Res. 25, 199–220 (1976)
Bantli, H., Bloedel, J.R., Tolbert, D.L.: Activation of neurons in the cerebellar nuclei and ascending reticular formation by stimulation of the cerebellar surface. J. Neurosurg. 45, 539–554 (1976)
Beitz, A.: The Afferent and Efferent Connections of the Dentate Nucleus in the Cat. University of Minnesota: Thesis 1976
Bishop, P.O., Burke, W., Davis, R.: The identification of single units in central visual pathways. J. Physiol. (Lond.) 162, 409–431 (1962)
Bishop, G.A., McCrea, R.A., Kitai, S.T.: An electrophysiological and anatomical study of the projection neurons in the nucleus interpositus of the cat. Anat. Rec. 187, 537–538 (1977)
Brodal, A.: Experimentelle Untersuchungen über die olivo-cerebellare Lokalisation. Z. ges. Neurol. Psychiat. 169, 1–153 (1940)
Brown, J.T., Chan-Palay, V., Palay, S.L.: Afferent input to the inferior olivary complex and its relation to cerebellar function. Neuroscience Abstracts 2, 97 (1976)
Chan-Palay, V.: Cerebellar Dentate Nucleus: Organization, Cytology and Transmitters. Berlin-Heidelberg-New York: Springer 1977
Flood, S., Jansen, J.: On the cerebellar nuclei in the cat. Acta anat. (Basel) 46, 52–72 (1961)
Freeman, W.J.: Mass Action in the Nervous System. New York: Academic Press 1975
Gilman, S.: A cerebello-thalamo-cortical pathway controlling fusimotor activity. In: Control of Posture and Locomotion (eds. R.B. Stein et al.). New York: Plenum Press 1974
Gould, B.B., Graybiel, A.M.: Afferents to the cerebellar cortex in the cat.: Evidence for an intrinsic pathway leading from the deep nuclei to the cortex. Brain Res. 110, 601–611 (1976)
Graham, R.C., Jr., Karnovsky, M.J.: The early stages of absorption of injected horseradish peroxidase in the proximal tubules of mouse kidney: ultrastructural cytochemistry by a new technique. J. Histochem. Cytochem. 14, 291–302 (1966)
Graybiel, A.M., Nauta, H.J.W., Lasek, R.J., Nauta, W.H.: A cerebello-olivary pathway in the cat: an experimental study using autoradiographic tracing techniques. Brain Res. 58, 205–211 (1973)
Hubel, D.H.: Single unit activity in the lateral geniculate body and optic tract of unrestrained cats. J. Physiol. (Lond.) 150, 91–104 (1960)
Kristensson, K., Olsson, Y.: Retrograde axonal transport of protein. Brain Res. 29, 363–365 (1971)
Larsell, O., Jansen, J.: The Comparative Anatomy and Histology of the Cerebellum: The Human Cerebellum, Cerebellar Connections, and Cerebellar Cortex. Minneapolis: University of Minnesota Press 1972
Martin, G.F., Henkel, C.K., King, J.S.: Cerebello-olivary fibers: Their origin, course and distribution in the North American oppossum. Exp. Brain. Res. 24, 219–236 (1976)
Massion, J.: Intervention des voies cerebello-corticales et cortico-cerebelleuses dans l'organisation et la regulation du mouvement. J. Physiol. (Paris) 67, 117A-170A (1973)
Nauta, H.J.W., Pritz, M.B., Lasek, R.J.: Afferents to the rat caudoputamen studied with horseradish peroxidase. An evaluation of a retrograde neuroanatomical research method. Brain Res. 67, 219–238 (1974)
Rall, W.: Distinguishing theoretical synaptic potentials computed for different soma-dentritic distributions of synaptic input. J. Neurophysiol. 30, 1138–1168 (1967)
Ramón y Cajal, S.: Histologie du système nerveux de l'homme et des vertébrés. Paris: Maloine 1909
Schultz, W., Montgomery, E.B., Jr., Marini, R.: Stereotyped flexion of the forelimb and hindlimb to microstimulation of dentate nucleus in cebus monkeys. Brain Res. 107, 151–155 (1976)
Snider, R.S.: Morphology of the cerebellar nuclei in the rabbit and the cat. J. comp. Neurol. 72, 399–415 (1940)
Thach, W.T.: Cerebellar output: properties, synthesis and uses. Brain Res. 40, 89–97 (1972)
Tolbert, D.L.: An anatomical study of cerebral and cerebellar projections to the rostral ventral thalamic nuclei in the cat. Anat. Rec. 178, 476 (1974)
Tolbert, D.L., Bantli, H., Bloedel, J.R.: Anatomical and physiological evidence for a cerebellar nucleocortical projection in the cat. Neuroscience 1, 205–217 (1976a)
Tolbert, D.L., Bantli, H., Bloedel, J.R.: Evidence for branching of cerebellar efferent axons. Neurosci. Abstr. 2, 118 (1976b)
Tolbert, D.L., Massopust, L.C., Murphy, M.G., Young, P.A.: The anatomical organization of the cerebello-olivary projection in the cat. J. comp. Neurol. 170, 525–544 (1976c)
Tolbert, D.L., Bantli, H., Bloedel, J.R.: The intracerebellar nucleocortical projection in a primate. Exp. Brain Res. (in press) (1977)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Tolbert, D.L., Bantli, H. & Bloedel, J.R. Multiple branching of cerebellar efferent projections in cats. Exp Brain Res 31, 305–316 (1978). https://doi.org/10.1007/BF00237291
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00237291