Elsevier

Brain Research

Volume 342, Issue 2, 9 September 1985, Pages 340-351
Brain Research

Organization of diencephalic dopamine neurones projecting to the spinal cord in the rat

https://doi.org/10.1016/0006-8993(85)91134-5Get rights and content

Abstract

Using the aluminium-formaldehyde method for visualization of catechlamines in combination with injections of the fluorescent retrograde tracer True Blue we have studied those diencephalic dopamine (DA)-containing cell groups which have been proposed to give rise to the DA innervation of the spinal cord and investigated the organization of the diencephalospinal DA system in detail. The A13 cell group was found to contain 370, and the A11 cell group 140, DA-producing cells on each side, whereas only very few such cells were found in the paraventricular hypothalamic nucleus. Tracer injections into the spinal cord labelled only DA cells within the A11 group. The overall majority of labelled cells were found ipsilaterally but some cells were also found contralaterally indicating the existence of a minor crossed dopaminergic projection to the spinal cord. Large tracer injections which covered the hemicord at different levels generally resulted in very similar distributions and numbers of retrogradely-labelled DA cells. The labelled DA-containing cells constituted 30–50% of the total number of labelled neurones in the ipsilateral A11 area and about 20–40% of the total number of DA containing cells in this area were labelled. Small injections that did not extend into the nucleus reticularis or the adjacent part of the lateral funiculus failed to label any diencephalic DA cells but usually labelled some non-DA cells in the A11 area. It is concluded that the diencephalospinal DA neurones have long axons that extend over several segments and possibly traverse the entire length of the spinal cord, giving off collateral branches at various levels. From the anatomical data of the present study and previous pharmacological and electrophysiological findings it seems possible that diencephalospinal DA neurones could modulate both sympathetic activity and nociception.

Reference (48)

  • JensenT.S. et al.

    Effects of an intrathecal dopamine agonist, apomorphine, on thermal and chemical evoked noxious responses in cats

    Brain Research

    (1984)
  • JonesE.G.

    Possible determinants of the degree of retrograde neuronal labeling with horseradish peroxidase

    Brain Research

    (1975)
  • LidbrinkP. et al.

    Selective reserpine-resistant accumulation of catecholamines in central dopamine neurones after DOPA administration

    Brain Research

    (1974)
  • LindvallO. et al.

    Selective histochemical demonstration of dopamine terminal systems in rat di- and telencephalon: new evidence for a dopaminergic innervation of hypothalamic neurosecretory nuclei

    Brain Research

    (1984)
  • Lore´nI. et al.

    The alimunium-formaldehyde (ALFA) histofluorescence method for improved visualization of catecholamines and indoleamines. I. A detailed account of the methodology for central nervous tissue using paraffin, cryostat or vibratome sectons

    J. Neurosci. Meth.

    (1980)
  • OnoT. et al.

    Paraventricular nucleus connections to spinal cord and pituitary

    Neurosci. Lett.

    (1978)
  • RhodesD.L. et al.

    Analgesia from rostral brain stem stimulation in the rat

    Brain Research

    (1978)
  • SaperC.B. et al.

    Direct hypothalamo-autonomic connections

    Brain Research

    (1976)
  • SimonO.R. et al.

    Spinal superfusion of dopamine excites renal sympathetic nerve activity

    Neuropharmacology

    (1983)
  • SkagerbergG. et al.

    Origin and termination of the diencephalo-spinal dopamine system in the rat

    Brain Res. Bull.

    (1982)
  • AbercrombieM.

    Estimation of nuclear population from microtome section

    Anat. Rec.

    (1946)
  • Bjo¨rklund, A. and Lindvall, O., Catecholamine-containing brain stem regulatory systems. In F. E. Bloom (Ed.)Handbook...
  • CommissiongJ.W. et al.

    Differentiation of dopaminergic and noradrenergic neurons in spinal cord

    J. Neurosci.

    (1978)
  • Dahlstro¨mA. et al.

    Evidence for the existence of monoamine-containing neurons in the central nervous system. I. Demonstration of monoamines in the cell bodies of brain stem neurons

    Acta physiol. scand.

    (1964)
  • Cited by (0)

    View full text