The termination pattern and postsynaptic targets of rubrospinal fibers in the rat spinal cord: A light and electron microscopic study

M. Antal, G. N. Sholomenko, A. K. Moschovakis, J. Storm-Mathisen, C. W. Heizmann, W. Hunziker

Research output: Contribution to journalArticle

75 Citations (Scopus)

Abstract

The spinal course, termination pattern, and postsynaptic targets of the rubrospinal tract, which is known to contribute to the initiation and execution of movements, were studied in the rat at the light and electron microscopic levels by using the anterograde tracer Phaseolus vulgaris- leucoagglutinin (PHA-L) in combination with calbindin-D28k (CaBP), γ- aminobutyric acid (GABA), and glycine immunocytochemistry. After injections of PHA-L unilaterally into the red nucleus, labelled fibers and terminals were detected at cervical, thoracic, and lumbar segments of the spinal cord. Most of the descending fibers were located in the dorsolateral funiculus contralateral to the injection site, but axons descending ipsilaterally were also revealed. Rubrospinal axon terminals were predominantly found in laminae V-VI and in the dorsal part of lamina VII at all levels and on both sides of the spinal cord, but stained collaterals were also seen in the ventrolateral aspect of Clark's column and in the ventral regions of lamina VII on both sides. The proportion of axonal varicosities revealed on the ipsilateral side varied at different segments and represented 10-28% of the total number of labelled boutons. Most of the labelled boutons were engaged in synaptic contacts with dendrites. Of the 137 rubrospinal boutons investigated, only 2 were found to establish axosomatic synaptic junctions in the lumbar spinal cord contralateral to the PHA-L injection. With the postembedding immunogold method, 80.8% of dendrites establishing synaptic contacts with rubrospinal terminals did not show immunoreactivity for either GABA or glycine, whereas 19.2% of them were immunoreactive for both amino acids. Rubrospinal axons made multiple contacts with CaBP-immunoreactive neurons in laminae V-VI. Synaptic contacts between rubrospinal terminals and CaBP-immunoreactive dendrites were identified at the electron microscopic level, and all CaBP- containing postsynaptic dendrites investigated were negative for both GABA and glycine. The results suggest that rubrospinal terminals establish synaptic contacts with both excitatory and inhibitory interneurons in the rat spinal cord, and a population of excitatory interneurons receiving monosynaptic rubrospinal input is located in laminae V-VI.

Original languageEnglish
Pages (from-to)22-37
Number of pages16
JournalJournal of Comparative Neurology
Volume325
Issue number1
DOIs
Publication statusPublished - 1992

Fingerprint

Spinal Cord
Dendrites
Electrons
Light
Glycine
gamma-Aminobutyric Acid
Presynaptic Terminals
Interneurons
Injections
Axons
Calbindin 1
Red Nucleus
Aminobutyrates
Thorax
Immunohistochemistry
Neurons
Amino Acids
Population
plants leukoagglutinins

Keywords

  • calbindin-D28k
  • descending fibers
  • GABA
  • glycine
  • Phaseolus vulgaris- leucoagglutinin
  • spinal interneurons

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

The termination pattern and postsynaptic targets of rubrospinal fibers in the rat spinal cord : A light and electron microscopic study. / Antal, M.; Sholomenko, G. N.; Moschovakis, A. K.; Storm-Mathisen, J.; Heizmann, C. W.; Hunziker, W.

In: Journal of Comparative Neurology, Vol. 325, No. 1, 1992, p. 22-37.

Research output: Contribution to journalArticle

Antal, M. ; Sholomenko, G. N. ; Moschovakis, A. K. ; Storm-Mathisen, J. ; Heizmann, C. W. ; Hunziker, W. / The termination pattern and postsynaptic targets of rubrospinal fibers in the rat spinal cord : A light and electron microscopic study. In: Journal of Comparative Neurology. 1992 ; Vol. 325, No. 1. pp. 22-37.
@article{7e52392dd46a4aba9e8b0a87033833a7,
title = "The termination pattern and postsynaptic targets of rubrospinal fibers in the rat spinal cord: A light and electron microscopic study",
abstract = "The spinal course, termination pattern, and postsynaptic targets of the rubrospinal tract, which is known to contribute to the initiation and execution of movements, were studied in the rat at the light and electron microscopic levels by using the anterograde tracer Phaseolus vulgaris- leucoagglutinin (PHA-L) in combination with calbindin-D28k (CaBP), γ- aminobutyric acid (GABA), and glycine immunocytochemistry. After injections of PHA-L unilaterally into the red nucleus, labelled fibers and terminals were detected at cervical, thoracic, and lumbar segments of the spinal cord. Most of the descending fibers were located in the dorsolateral funiculus contralateral to the injection site, but axons descending ipsilaterally were also revealed. Rubrospinal axon terminals were predominantly found in laminae V-VI and in the dorsal part of lamina VII at all levels and on both sides of the spinal cord, but stained collaterals were also seen in the ventrolateral aspect of Clark's column and in the ventral regions of lamina VII on both sides. The proportion of axonal varicosities revealed on the ipsilateral side varied at different segments and represented 10-28{\%} of the total number of labelled boutons. Most of the labelled boutons were engaged in synaptic contacts with dendrites. Of the 137 rubrospinal boutons investigated, only 2 were found to establish axosomatic synaptic junctions in the lumbar spinal cord contralateral to the PHA-L injection. With the postembedding immunogold method, 80.8{\%} of dendrites establishing synaptic contacts with rubrospinal terminals did not show immunoreactivity for either GABA or glycine, whereas 19.2{\%} of them were immunoreactive for both amino acids. Rubrospinal axons made multiple contacts with CaBP-immunoreactive neurons in laminae V-VI. Synaptic contacts between rubrospinal terminals and CaBP-immunoreactive dendrites were identified at the electron microscopic level, and all CaBP- containing postsynaptic dendrites investigated were negative for both GABA and glycine. The results suggest that rubrospinal terminals establish synaptic contacts with both excitatory and inhibitory interneurons in the rat spinal cord, and a population of excitatory interneurons receiving monosynaptic rubrospinal input is located in laminae V-VI.",
keywords = "calbindin-D28k, descending fibers, GABA, glycine, Phaseolus vulgaris- leucoagglutinin, spinal interneurons",
author = "M. Antal and Sholomenko, {G. N.} and Moschovakis, {A. K.} and J. Storm-Mathisen and Heizmann, {C. W.} and W. Hunziker",
year = "1992",
doi = "10.1002/cne.903250103",
language = "English",
volume = "325",
pages = "22--37",
journal = "Journal of Comparative Neurology",
issn = "0021-9967",
publisher = "Wiley-Liss Inc.",
number = "1",

}

TY - JOUR

T1 - The termination pattern and postsynaptic targets of rubrospinal fibers in the rat spinal cord

T2 - A light and electron microscopic study

AU - Antal, M.

AU - Sholomenko, G. N.

AU - Moschovakis, A. K.

AU - Storm-Mathisen, J.

AU - Heizmann, C. W.

AU - Hunziker, W.

PY - 1992

Y1 - 1992

N2 - The spinal course, termination pattern, and postsynaptic targets of the rubrospinal tract, which is known to contribute to the initiation and execution of movements, were studied in the rat at the light and electron microscopic levels by using the anterograde tracer Phaseolus vulgaris- leucoagglutinin (PHA-L) in combination with calbindin-D28k (CaBP), γ- aminobutyric acid (GABA), and glycine immunocytochemistry. After injections of PHA-L unilaterally into the red nucleus, labelled fibers and terminals were detected at cervical, thoracic, and lumbar segments of the spinal cord. Most of the descending fibers were located in the dorsolateral funiculus contralateral to the injection site, but axons descending ipsilaterally were also revealed. Rubrospinal axon terminals were predominantly found in laminae V-VI and in the dorsal part of lamina VII at all levels and on both sides of the spinal cord, but stained collaterals were also seen in the ventrolateral aspect of Clark's column and in the ventral regions of lamina VII on both sides. The proportion of axonal varicosities revealed on the ipsilateral side varied at different segments and represented 10-28% of the total number of labelled boutons. Most of the labelled boutons were engaged in synaptic contacts with dendrites. Of the 137 rubrospinal boutons investigated, only 2 were found to establish axosomatic synaptic junctions in the lumbar spinal cord contralateral to the PHA-L injection. With the postembedding immunogold method, 80.8% of dendrites establishing synaptic contacts with rubrospinal terminals did not show immunoreactivity for either GABA or glycine, whereas 19.2% of them were immunoreactive for both amino acids. Rubrospinal axons made multiple contacts with CaBP-immunoreactive neurons in laminae V-VI. Synaptic contacts between rubrospinal terminals and CaBP-immunoreactive dendrites were identified at the electron microscopic level, and all CaBP- containing postsynaptic dendrites investigated were negative for both GABA and glycine. The results suggest that rubrospinal terminals establish synaptic contacts with both excitatory and inhibitory interneurons in the rat spinal cord, and a population of excitatory interneurons receiving monosynaptic rubrospinal input is located in laminae V-VI.

AB - The spinal course, termination pattern, and postsynaptic targets of the rubrospinal tract, which is known to contribute to the initiation and execution of movements, were studied in the rat at the light and electron microscopic levels by using the anterograde tracer Phaseolus vulgaris- leucoagglutinin (PHA-L) in combination with calbindin-D28k (CaBP), γ- aminobutyric acid (GABA), and glycine immunocytochemistry. After injections of PHA-L unilaterally into the red nucleus, labelled fibers and terminals were detected at cervical, thoracic, and lumbar segments of the spinal cord. Most of the descending fibers were located in the dorsolateral funiculus contralateral to the injection site, but axons descending ipsilaterally were also revealed. Rubrospinal axon terminals were predominantly found in laminae V-VI and in the dorsal part of lamina VII at all levels and on both sides of the spinal cord, but stained collaterals were also seen in the ventrolateral aspect of Clark's column and in the ventral regions of lamina VII on both sides. The proportion of axonal varicosities revealed on the ipsilateral side varied at different segments and represented 10-28% of the total number of labelled boutons. Most of the labelled boutons were engaged in synaptic contacts with dendrites. Of the 137 rubrospinal boutons investigated, only 2 were found to establish axosomatic synaptic junctions in the lumbar spinal cord contralateral to the PHA-L injection. With the postembedding immunogold method, 80.8% of dendrites establishing synaptic contacts with rubrospinal terminals did not show immunoreactivity for either GABA or glycine, whereas 19.2% of them were immunoreactive for both amino acids. Rubrospinal axons made multiple contacts with CaBP-immunoreactive neurons in laminae V-VI. Synaptic contacts between rubrospinal terminals and CaBP-immunoreactive dendrites were identified at the electron microscopic level, and all CaBP- containing postsynaptic dendrites investigated were negative for both GABA and glycine. The results suggest that rubrospinal terminals establish synaptic contacts with both excitatory and inhibitory interneurons in the rat spinal cord, and a population of excitatory interneurons receiving monosynaptic rubrospinal input is located in laminae V-VI.

KW - calbindin-D28k

KW - descending fibers

KW - GABA

KW - glycine

KW - Phaseolus vulgaris- leucoagglutinin

KW - spinal interneurons

UR - http://www.scopus.com/inward/record.url?scp=0026697720&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026697720&partnerID=8YFLogxK

U2 - 10.1002/cne.903250103

DO - 10.1002/cne.903250103

M3 - Article

C2 - 1484116

AN - SCOPUS:0026697720

VL - 325

SP - 22

EP - 37

JO - Journal of Comparative Neurology

JF - Journal of Comparative Neurology

SN - 0021-9967

IS - 1

ER -