Summary
-
1.
The activation of neurones in the mLRN (major portion of lateral reticular nucleus comprising its parvi- and magnocellular parts) by a spinal path ascending in the dorsal funiculus (DF) and by trigeminal afferents has been studied.
-
2.
Stimulation of the DF at C3 activated about one half of the mLRN neurones. The latencies were 2–28 ms. In experiments with the spinal cord interrupted at C3 except for the DF it was shown that cutaneous and high threshold muscle afferents in mainly forelimb nerves were effective. The latencies of the responses to nerve stimulation were 8–27 ms.
-
3.
Stimulation of trigeminal afferents evoked a response in about one third of the mLRN neurones. The latencies were 2–27 ms.
-
4.
Activation from the DF- and trigeminal paths occurred often in the same mLRN neurones and the neurones activated from the two paths had a similar location in the nucleus and a similar termination in the cerebellar cortex.
-
5.
The DF- and trigeminal paths had similar properties. Activation was evoked from both ipsilateral and contralateral nerves. Fast adapting hair receptors were commonly effective.
-
6.
Evidence is presented indicating that the DF- and trigeminal paths share a common final path to the mLRN neurones which is formed by brain stem interneurones intercalated between the DF- and trigeminal nuclei and the mLRN. It is suggested that these interneurones represent a supraspinal motor centre.
-
7.
Activation from the DF- and trigeminal paths occurred with unequal frequency among groups of mLRN neurones activated from different spinal paths ascending in the ipsilateral lateral funiculus (cf. Clendenin et al., 1974a).
Similar content being viewed by others
References
Bruckmoser, P., Hepp-Reymond, M.-C., Wiesendanger, M.: Cortical influence on single neurons of the lateral reticular nucleus of the cat. Exp. Neurol. 26, 239–252 (1970)
Busch, H.F.M.: An anatomical analysis of the white matter in the brain stem of the cat. Thesis. 116 pp. Assen: Van Gorcum & Comp. 1961
Clendenin, M., Ekerot, C.-E., Oscarsson, O.: The lateral reticular nucleus in the cat. III. Organization of component activated from ipsilateral forelimb tract. Exp. Brain Res. 21, 501–513 (1974a)
Clendenin, M., Ekerot, C.-E., Oscarsson, O., Rosén, L: The lateral reticular nucleus in the cat. I. Mossy fibre distribution in cerebellar cortex. Exp. Brain Res. 21, 473–486 (1974b)
Clendenin, M., Ekerot, C.-E., Oscarsson, O., Rosén, I.: The lateral reticular nucleus in the cat. II. Organization of component activated from bilateral ventral flexor reflex tract (bVFRT). Exp. Brain Res. 21, 487–500 (1974c)
Cooke, J.D., Larson, B., Oscarsson, O., Sjölund, B.: Origin and termination of cuneocerebellar tract. Exp. Brain Res. 13, 339–358 (1971a)
Cooke, J.D., Larson, B., Oscarsson, O., Sjölund, B.: Organization of afferent connections to cuneocerebellar tract. Exp. Brain Res. 13, 359–377 (1971b)
Crichlow, E.C., Kennedy, T.T.: Functional characteristics of neurons in the lateral reticular nucleus with reference to localized cerebellar potentials. Exp. Neurol. 18, 141–153 (1967)
Darian-Smith, I., Phillips, G.: Secondary neurones within a trigemino-cerebellar projection to the anterior lobe of the cerebellum in the cat. J. Physiol. (Lond.) 170, 53–68 (1964)
Ebbesson, S.O.E.: A connection between the dorsal column nuclei and the dorsal accessory olive. Brain Res. 8, 393–397 (1968)
Ekerot, C.-E., Oscarsson, O.: Inhibitory spinal paths to the lateral reticular nucleus in the cat. Brain Res. 99, 157–161 (1975)
Hand, P., Liu, C.N.: Efferent projections of the nucleus gracilis. Anat. Rec. 154, 353–354 (1966)
Kuypers, H.G.J.M., Tuerk, J.D.: The distribution of the cortical fibres within the nuclei cuneatus and gracilis in the cat. J. Anat. (Lond.) 98, 143–162 (1964)
Oscarsson, O.: Functional organization of spinocerebellar paths. In: Handbook of Sensory Physiology. Vol. II. Somatosensory System. (Ed. A. Iggo), pp. 339–380. Berlin-Heidelberg-New York: Springer 1973
Rosén, I., Scheid, P.: Patterns of afferent input to the lateral reticular nucleus of the cat. Exp. Brain Res. 18, 242–255 (1973a)
Rosén, I., Scheid, P.: Responses to nerve stimulation in the bilateral ventral flexor reflex tract of the cat. Exp. Brain Res. 18, 256–267 (1973b)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Clendenin, M., Ekerot, C.F. & Oscarsson, O. The lateral reticular nucleus in the cat IV. Activation from dorsal funiculus and trigeminal afferents. Exp Brain Res 24, 131–144 (1975). https://doi.org/10.1007/BF00234059
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00234059