Skip to main content
SpringerLink
Log in

Spinal projections to the lateral reticular nucleus in the rat

  • Published:
Anatomy and Embryology Aims and scope Submit manuscript

Summary

The synaptic relationships and the distribution of the afferent terminals of the spinal pathway to the lateral reticular nucleus (LRN) of the rat were examined following induced degeneration. After high cervical hemisections, the spino-LRN projection was first examined with the Fink-Heimer silver impregnation method. Degeneration was confined primarily to the ipsilateral LRN and all three divisions of the nucleus were involved. Maximum degeneration was observed in the caudal regions of the parvocellular division. The magnocellular division, except for the extreme dorsomedial area, showed substantial degeneration as well. The subtrigeminal division throughout its entire length contained only sparse degeneration.

Electron microscopic examination following spinal cord lesions revealed both round and pleomorphic-vesicle terminals in various stages of electron dense degeneration. The majority of the degenerating terminals were of the round-vesicle variety. Both types of terminals contacting somata were also observed to degenerate but their number was small in comparison to those on dendritic profiles. Terminals in synaptic contact with two dendritic profiles were also observed to degenerate. Some of the large terminals belonging to synaptic configurations (glomeruli) underwent degeneration and were therefore of spinal origin as well.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Andrezik JA, King JS (1977) The lateral nucleus of the opossum (Didelphis virginiana). I. Conformation, cytology, and synaptology. J Comp Neurol 174:119–150

    Google Scholar 

  • Brodal A (1949) Spinal afferents to the lateral reticular nucleus of the medulla oblongata in the cat. An experimental study. J Comp Neurol 91:259–295

    Google Scholar 

  • Brodal P, Marsula J, Brodal A (1967) The cerebral cortical projection to the lateral reticular nucleus in the cat, with special reference to the sensorimotor cortical areas. Brain Res 6:252–274

    Google Scholar 

  • Clendenin M, Ekerot C-F, Oscarsson O (1974a) The lateral reticular nucleus in the cat. III. Organization of component activated from ipsilateral forelimb tract. Exp Brain Res 21:501–513

    Google Scholar 

  • Clendenin M, Ekerot C-F, Oscarsson O, Rosén I (1974b) Functional organization of two spinocerebellar paths relayed through the lateral reticular nucleus in the cat. Brain Res 69:140–143

    Google Scholar 

  • Clendenin M, Ekerot C-F, Oscarsson O, Rosén I (1974c) 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

    Google Scholar 

  • Clendenin M, Ekerot C-F, Oscarsson O (1975) The lateral reticular nucleus in the cat. IV. Activation from dorsal funiculus and trigeminal afferents. Exp Brain Res 24:131–144

    Google Scholar 

  • Corvaja N, Grofová I, Pompeiano O, Walberg F (1977a) The lateral reticular nucleus in the cat. I. An experimental anatomical study of its spinal and supraspinal afferent connections. Neuroscience 2:537–553

    Google Scholar 

  • Corvaja N, Grofová I, Pompeiano O, Walberg F (1977b) The lateral reticular nucleus in the cat. II. Effects of lateral reticular lesions on posture and reflex movements. Neuroscience 2:929–943

    Google Scholar 

  • Courville J (1966) Rubrobulbar fibres to the facial nucleus and the lateral reticular nucleus (nucleus of the lateral funiculus). An experimental study in the cat with silver impregnation methods. Brain Res 1:317–337

    Google Scholar 

  • Coulter JD, Mergner T, Pompeiano O (1974) Macular influences on ascending spinoreticular neurons located in the cervical cord. Brain Res 82:322–327

    Google Scholar 

  • Coulter JD, Mergner T, Pompeiano O (1976) Effects of static tilt on cervical spinoreticular tract neurons. J Neurophysiol 39:45–62

    Google Scholar 

  • Eccles JC (1964) The physiology of synapses. Springer-Verlag, New York, pp 201–215

    Google Scholar 

  • Eccles JC (1973) The understanding of the brain. McGraw-Hill, New York

    Google Scholar 

  • Ekerot C-F, Oscarsson O (1975) Inhibitory spinal paths to the lateral reticular nucleus. Brain Res 99:157–161

    Google Scholar 

  • Fink RP, Heimer L (1967) Two methods for selective silver impregnation of degenerating axons and their synaptic endings in the central nervous system. Brain Res 4:369–374

    Google Scholar 

  • Flumerfelt BA, Kapogianis EM, Hrycyshyn AW (1982) An ultrastructural study of the lateral reticular nucleus in the rat. Anat Embryol 165:329–344

    Google Scholar 

  • Grillner S, Hongo T, Lunc S (1968) The origin of descending fibres monosynaptically activating spinorecticular neurons. Brain Res 10:259–262

    Google Scholar 

  • Grundfest H, Carter WB (1954) Afferent relations of inferior olivary nucleus. I. Electrophysiological demonstration of dorsal spino-olivary tract in cat. J Neurophysiol 17:72–91

    Google Scholar 

  • Hrycyshyn AW, Flumerfelt BA (1981a) A light microscopic investigation of the afferent connections of the lateral reticular nucleus in the cat. J Comp Neurol 197:477–502

    Google Scholar 

  • Hrycyshyn AW, Flumerfelt BA (1981b) An electron microscopic study of the afferent connections of the lateral reticular nucleus of the cat. J Comp Neurol 197:503–516

    Google Scholar 

  • Kapogianis EW, Flumerfelt BA, Hrycyshyn AW (1982) A Golgi study of the lateral reticular nucleus in the rat. Anat Embryol 164:243–256

    Google Scholar 

  • Kawamura K, Brodal A, Hoddevik G (1974) The projection of the superior colliculus onto the reticular formation of the brain stem. An experimental anatomical study in the cat. Exp Brain Res 19:1–19

    Google Scholar 

  • Kitai ST, DeFrance JF, Hatada K, Kennedy DT (1974a) Electrophysiological properties of lateral reticular nucleus cells. II. Synaptic activation. Exp Brain Res 21:419–432

    Google Scholar 

  • Kitai ST, Kennedy DT, DeFrance JF, Hatada K (1974b) Electrophysiological properties of lateral reticular nucleus cells. I. Antidromic activation. Exp Brain Res 21:403–418

    Google Scholar 

  • Kubin L, Magherini PC, Manzoni D, Pompeiano O (1980) Responses of lateral reticular neurons to sinusoidal stimulation of labyrinth receptors in decerebrate cat. J Neurophysiol 44:922–936

    Google Scholar 

  • Künzle H (1973) The topographic organization of spinal afferents to the lateral reticular nucleus of the cat. J Comp Neurol 149:103–116

    Google Scholar 

  • Ladpli R, Brodal A (1968) Experimental studies of commissural and reticular formation projections from the vestibular nuclei in the cat. Brain Res 8:65–69

    Google Scholar 

  • Lundberg A, Oscarsson O (1962) Two ascending spinal pathways in the ventral part of the cord. Acta Physiol Scand 54:270–286

    Google Scholar 

  • Martin GF, Andrezik J, Crutcher K, Linauts M, Panneton M (1977) The lateral reticular nucleus of the opossum. (Didelphis virginiana) II. Connections. J Comp Neurol 174:151–186

    Google Scholar 

  • Mathers LH (1972) The synaptic organization of the cortical projection to the pulvinar of the squirrel monkey. J Comp Neurol 146:43–59

    Google Scholar 

  • McLaughlin BJ (1972a) The fine structure of neurons and synapses in the motor nuclei of the cat spinal cord. J Comp Neurol 144:429–459

    Google Scholar 

  • McLaughlin BJ (1972b) Propriospinal and supra-spinal projections to the motor nuclei in the cat spinal cord. J Comp Neurol 144:475–499

    Google Scholar 

  • Mehler WR, Feferman ME, Nauta WJH (1960) Ascending axon degeneration following anterolateral cordotomy. An experimental study in the monkey. Brain 83:718–750

    Google Scholar 

  • Mizuno N, Konishi A, Nakamura Y (1975) An electron microscope study of synaptic organization in the lateral reticular neucleus of the medulla oblongata in the cat. Brain Res 94:369–381

    Google Scholar 

  • Mizuno N, Nakamura Y (1973) An electron microscope study of spinal afferents to the lateral reticular nucleus of the medulla oblongata in the cat. Brain Res 53:187–191

    Google Scholar 

  • Morin F, Kennedy DT, Gardner E (1966) Spinal afferents to the lateral reticular nucleus. I. A histological study. J Comp Neurol 126:511–522

    Google Scholar 

  • Nauta WJH (1957) Silver impregnation of degenerating axons. In: Windle WF (ed) New research techniques of neuroanatomy. Thomas, Springfield, pp 17–26

    Google Scholar 

  • Oscarsson O (1967) Functional significance of information channels from the spinal cord to the cerebellum. In: Yahr MD, Purpura DP (eds) Neurophysiological basis of normal and abnormal motor activities. Raven/Hewlett, New York, pp 93–117

    Google Scholar 

  • Oscarsson O (1973) Functional organization of spinocerebellar paths. In: Iggo A (ed) Handbook of sensory physiology. Vol. 2 Somatosensory systems. Springer-Verlag, New York, pp 339–380

    Google Scholar 

  • Oscarsson O, Rosén I (1966) Response characteristics of reticulocerebellar neurons activated from spinal afferents. Exp Brain Res I:320–328

    Google Scholar 

  • Rao GS, Breazile JE, Kitchell RL (1969) Distribution and termination of spinoreticular afferents in the brain stem of sheep. J Comp Neurol 137:185–196

    Google Scholar 

  • Rosén I, Scheid P (1972) Cutaneous afferent responses in neurons of the lateral reticular nucleus. Brain Res 43:259–263

    Google Scholar 

  • Rosén I, Scheid P (1973a) Patterns of afferent input in the lateral reticular nucleus of the cat. Exp Brain Res 18:242–255

    Google Scholar 

  • Rosén I, Scheid P (1973b) Responses to nerve stimulation in the bilateral ventral flexor reflex tract (bVFRT) of the cat. Exp Brain Res 18:257–267

    Google Scholar 

  • Rosén I, Scheid P (1973c) Responses in the spino-reticulo-cerebellar pathways to stimulation of cutaneous mechanoreceptors. Exp Brain Res 18:268–278

    Google Scholar 

  • Szentágothai J (1970) Glomerular synapses, complex synaptic arrangements and their operational significance. In: Schmitt FO (ed) The neurosciences: second study program. Rockefeller Press, New York, pp 427–443

    Google Scholar 

  • Uchizono K (1965) Characteristics of excitatory and inhibitory synapses in the central nervous system of the cat. Nature (Lond) 207:642–643

    Google Scholar 

  • Verhaart WJC (1957) The lateral reticular nucleus of the medulla oblongata and the passing fibre systems of the lateral funiculus. Acta Psychiat Scand 32:211–229

    Google Scholar 

  • Walberg F, Pompeiano O (1960) Fastigiofugal fibres to the lateral reticular nucleus: An experimental study in the cat. Exp Neurol 2:40–53

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Anatomy, The University of Western Ontario, N6A 5C1, London, Ontario, Canada

    B. A. Flumerfelt, A. W. Hrycyshyn & E. M. Kapogianis

Authors
  1. B. A. Flumerfelt
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. A. W. Hrycyshyn
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. E. M. Kapogianis
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Flumerfelt, B.A., Hrycyshyn, A.W. & Kapogianis, E.M. Spinal projections to the lateral reticular nucleus in the rat. Anat Embryol 165, 345–359 (1982). https://doi.org/10.1007/BF00305572

Download citation

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00305572

Key words

Search

Navigation