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Electron microscopic evidence of a monosynaptic pathway between cells in the caudal raphé nuclei and sympathetic preganglionic neurons in the rat spinal cord

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Electrophysiological and anatomical studies have suggested the existence of a pathway between the caudal raphé nuclei and regions of the spinal cord containing the sympathetic preganglionic neurons. However synaptic connections between cells in the raphé nuclei and identified sympathetic preganglionic neurons have not yet been shown. We have used a combination of anterograde tracing using Phaseolus vulgaris leucoagglutinin (PHA-L), retrograde tracing using a conjugate of cholera B chain and HRP and electron microscopy to look for such a pathway in rats. When PHA-L had been injected into the regions mainly restricted to the raphé pallidus and raphé magnus, synaptic contacts were found between PHA-L containing terminals and preganglionic neurons retrogradely labelled from the adrenal medulla. Out of the 43 synaptic contacts analysed, 26 were onto somata and 14 onto dendrites. 75% of the total appeared to have symmetric membrane specialisations, 20% asymmetric and the remainder could not be classified. Synaptic contacts were not seen in an animal in which the PHA-L injection site involved cells in the ventral raphé obscurus and surrounding gigantocellular reticular formation. These findings provide evidence of the existence of a direct monosynaptic pathway between cells in the raphé pallidus and/or caudal raphé magnus, and identified sympathetic preganglionic neurons and give further support for a role for the caudal raphé nuclei in sympathetic autonomic regulation.

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References

  • Adair JR, Hamilton BL, Scappaticci KA, Helke CJ, Gillis RA (1977) Cardiovascular responses to electrical stimulation of the medullary raphé area of the cat. Brain Res 128: 141–145

    Google Scholar 

  • Amendt K, Czachurski J, Dembowsky K, Sellar H (1979) Bulbospinal projections to the intermediolateral cell column: a neuroanatomical study. J Auton Nerv Syst 1: 103–117

    Google Scholar 

  • Bacon SJ, Smith AD (1988) Preganglionic sympathetic neurones innervating the rat adrenal medulla: immunocytochemical evidence of synaptic input from nerve terminals containing substance P, GABA or 5-hydroxytryptamine. J Auton Nerv Syst 24: 97–122

    Google Scholar 

  • Basbaum AI, Fields HL (1979) The origin of descending pathways in the dorsolateral funiculus of the spinal cord of the cat and rat: further studies on the anatomy of pain modulation. J Comp Neurol 187: 513–532

    Google Scholar 

  • Basbaum AL, Clanton CH, Fields HL (1978) Three bulbospinal pathways from the rostral medulla of the cat: an autoradiographic study of pain modulating systems. J Comp Neurol 178: 209–224

    Google Scholar 

  • Blessing WW, Goodchild AK, Dampney RAL, Chalmers JP (1981) Cell groups in the lower brainstem of the rabbit projecting to the spinal cord, with special reference to catecholamine-containing neurons. Brain Res 221: 35–55

    Google Scholar 

  • Bowker RM, Steinbusch HWM, Coulter JD (1981) Serotonergic and peptidergic projections to the spinal cord demonstrated by a combined retrograde HRP histochemical and immunohistochemical staining method. Brain Res 211: 412–417

    Google Scholar 

  • Bowker RM, Westlund KN, Sullivan MC, Coulter JD (1982) A combined retrograde transport and immunocytochemical staining method for demonstrating the origins of serotonergic projections. J Histochem Cytochem 30: 805–810

    Google Scholar 

  • Bowker RM, Westlund KN, Sullivan MC, Wilber JF, Coulter JD (1983) Descending serotonergic, peptidergic and cholinergic pathways from the raphé nuclei: a multiple transmitter complex. Brain Res 288: 33–48

    Google Scholar 

  • Brodal A, Taber E, Walberg F (1960) The raphé nuclei of the brainstem of the cat. II. Efferent connections. J Comp Neurol 114: 239–259

    Google Scholar 

  • Cabot JB, Reiner A, Bogan N (1982) Avian bulbospinal pathways: anterograde and retrograde studies of cells of origin, funicular trajectories and laminar terminations. Prog Brain Res 2: 79–108

    Google Scholar 

  • Cabot JB, Wild JM, Cohen DB (1979) Raphé inhibition of sympathetic preganglionic neurons. Science 3: 184–186

    Google Scholar 

  • Chiba T, Murata Y (1981) Architecture and synaptic relationships in the intermediolateral nucleus of the thoracic spinal cord of the rat: HRP labelling, catecholamine histochemistry and electron microscopic studies. J Neurocytol 10: 315–329

    Google Scholar 

  • Chung K, La Velle FW, Wurster RD (1980) Ultrastructure of HRP-identified sympathetic preganglionic neurons in cats. J Comp Neurol 190: 147–155

    Google Scholar 

  • Coote JH, McLeod VH (1974) The influence of bulbospinal monoaminergic pathways on sympathetic nerve activity. J Physiol (Lond) 241: 453–475

    Google Scholar 

  • Coote JH (1988) The organisation of cardiovascular neurons in the spinal cord. Rev Physiol Biochem Pharmacol 110: 148–285

    Google Scholar 

  • Crutcher KA, Humbertson AO, Martin GF (1978) The origins of brainstem spinal pathways in the North American opossum (Didelphis virginiana): studies with the horseradish peroxidase method. J Comp Neurol 179: 169–174

    Google Scholar 

  • Dahlström A, Fuxe K (1964) Evidence for the existance of monoamine neurons in the central nervous system. I. Demonstration of monoamines in the cell bodies of brain stem neurones. Acta Physiol Scand 62 Suppl 232: 1–55

    Google Scholar 

  • Dahlström A, Fuxe K (1965) Evidence for the existance of monoamine neurons in the central nervous system. II. Experimentally induced changes in the intraneuronal amine levels in bulbospinal neuron systems. Acta Physiol Scand 64, Suppl 247: 7–34

    Google Scholar 

  • DeGroat WC, Ryall RW (1967) An excitatory action of 5-hydroxytryptamine on sympathetic preganglionic neurones. Exp Brain Res 3: 299–305

    Google Scholar 

  • Eldred WD, Zucker C, Karten HJ, Yazulla S (1983) Comparison of fixation and penetration enhancement techniques for use in ultrastructural immunocytochemistry. J Histochem Cytochem 31: 285–292

    Google Scholar 

  • Gebber GL, McCall RB (1976) Identification and discharge patterns of spinal sympathetic interneurones. Am J Physiol 231: 722–733

    Google Scholar 

  • Gerfen CR, Sawchenko PE (1984) An anterograde neuroanatomical tracing method that shows the detailed morphology of neurons, their axons and terminals: immunohistochemical localisation of an axonally transported plant lectin, Phaseclus vulgaris leucoagglutinin (PHA-L). Brain Res 290: 219–238

    Google Scholar 

  • Gilbey MP, Coote JH, Macleod VH, Peterson DF (1981) Inhibition of sympathetic activity by stimulation of the raphé nuclei and the role of 5-HT in this effect. Brain Res 226: 131–142

    Google Scholar 

  • Hadjiconstantinou M, Panoula P, Lackovic Z, Neff NH (1984) Spinal cord serotonin: a biochemical and immunohistochemical study following transection. Brain Res 322: 245–254

    Google Scholar 

  • Hancock MB (1982) DAB-Nickel substrate for the differential immunoperoxidase staining of nerve fibres and fiber terminals. J Histochem Cytochem 30:578P

    Google Scholar 

  • Haselton JR, Winters RW, Liskowsky DR, Haselton CL, McCabe PM, Schneiderman N (1988) Anatomical and functional connections of neurons of the rostral medullary raphé of the rabbit. Brain Res 453: 176–182

    Google Scholar 

  • Henry JL, Calaresu FR (1972) Distribution of cardioacceleratory sites in intermediolateral nucleus of the cat. Am J Physiol 222: 700–704

    Google Scholar 

  • Henry JL, Calaresu FR (1974) Pathways from medullary nuclei to spinal cardioacceleratory neurones in the cat. Exp Brain Res 20: 505–514

    Google Scholar 

  • Holets V, Elde RP (1982) The differential distribution and relationship of serotonergic and peptidergic fibers to sympathoadrenal neurons in the intermediolateral cell column of the rat: a combined retrograde axonal transport and immunofluorescence study. Neuroscience 7: 1155–1174

    Google Scholar 

  • Hökfelt T, Ljungdahl Å, Steinbusch H, Verhofstad AAJ, Nilsson G, Brodin E, Pernow B, Goldstein M (1978) Immunohistochemical evidence of substance P-like immunoreactivity in some 5-hydroxytryptamine-containing neurons in the rat central nervous system. Neuroscience 3: 517–538

    Google Scholar 

  • Humphrey DR (1967) Neuronal activity in the medulla oblongata of the cat evoked by stimulation of the carotid sinus nerve. P. Kezdi (ed): Baroreceptors and hypertension. Pergamon Press, Toronto, pp 131–168

    Google Scholar 

  • Key BJ, Loudon RF (1987) Involvement of 5-hydroxytryptamine in the blood pressure changes evoked by electrical stimulation of the median raphé nucleus. Neuropharmacology 26: 1787–1790

    Google Scholar 

  • Kosofsky BE, Molliver ME (1987) The serotonergic innervation of cerebral cortex: different classes of axon terminals arise from dorsal and madian raphé nuclei. Synapse 1: 153–168

    Google Scholar 

  • Koss MC, Wang SC (1972) Brainstem loci for sympathetic activation of the nictitating membrane and pupil in the cat. Am J Physiol 222: 900–912

    Google Scholar 

  • Kuypers HGJM, Maisky VA (1975) Retrograde axonal transport of horseradish peroxidase from spinal cord to brainstem cell groups in the cat. Neurosci Lett 1: 9–14

    Google Scholar 

  • Light AR, Kavookjian AM (1985) The ultrastructure and synaptic connections of the spinal terminations from single, physiologically characterised axons descending in the dorsolateral funiculus from the midline pontomedullary region. J Comp Neurol 234: 549–560

    Google Scholar 

  • Loewy AD, McKeller S (1981) Serotonergic projections from the ventral medulla to the intermediolateral cell column in the rat. Brain Res 211: 146–152

    Google Scholar 

  • Loewy AD, (1981) Raphé pallidus and raphé obscurus projections to the intermediolateral cell column in the rat. Brain Res 222: 129–133

    Google Scholar 

  • Marson L (1989) Evidence for colocalization of substance P and 5-hydroxytryptamine in spinally projecting neurons from the cat medulla oblongata. Neurosci Lett 96: 54–59

    Google Scholar 

  • Martin RF, Jordan LM, Willis WD (1978) Differential projections of cat medullary raphé neurons demonstrated by retrograde labelling following spinal cord lesions. J Comp Neurol 182: 77–88

    Google Scholar 

  • McIllhinney RAJ, Bacon SJ, Smith AD (1988) A simple and rapid method for the production of cholera B-chain coupled to horseradish peroxidase for neuronal tracing. J Neurosci Meth 22: 189–194

    Google Scholar 

  • Minson JB, Chalmers JP, Caon AC, Renaud B (1987) Separate areas of rat medulla oblongata with populations of serotonin- and adrenaline-containing neurons alter blood pressure after L-glutamate stimulation. J Auton Nerv Syst 19: 39–50

    Google Scholar 

  • Morrison SF, Gebber GL (1982) Classification of raphé neurons with cardiac related activity. Am J Physiol 243: R49-R59

    Google Scholar 

  • Morrison SF, Gebber GL (1984) Raphe neurons with sympathetic related activity: baroreceptor responses and spinal connections. Am J Physiol 246: R338-R348

    Google Scholar 

  • Morrison SF, Gebber GL (1985) Axonal branching patterns and funicular trajectories of raphé spinal sympathoinhibitory neurons. J Neurophysiol 53: 759–772

    Google Scholar 

  • Muira M, Reis DJ (1969) Termination and secondary projections of the carotid sinus nerve in the cat brainstem. Am J Physiol 217: 142–153

    Google Scholar 

  • Neumayr RJ, Hare BD, Franz DN (1974) Evidence for bulbospinal control of sympathetic preganglionic neurons by monoaminergic pathways. Life Sci 14: 793–806

    Google Scholar 

  • Newman DB (1983) Distinguishing rat brainstem reticulo-spinal nuclei by their neuronal morphology 1. Medullary nuclei. J Hirnforsch 26: 187–226

    Google Scholar 

  • Newton BW, Hamill RW (1989) Immunohistochemical demonstration of serotonin in spinal autonomic nuclei 1. Fiber patterns in the adult rat. J Comp Neurol 279: 68–81

    Google Scholar 

  • Newton BW, Maley BE, Hamill RW (1986) Immunohistochemical demonstration of serotonin neurons in the autonomic regions of the rat spinal cord. Brain Res 376: 155–163

    Google Scholar 

  • Paxinos G, Watson C (1986) The rat brain in stereotaxic coordinates. Academic Press

  • Pilowsky PM, Kapoor V, Minson JB, West MJ, Chalmers JP (1986) Spinal cord serotonin release and raised blood pressure after brainstem kaininc acid injection. Brain Res 366: 354–357

    Google Scholar 

  • Reynolds ES (1963) The use of lead citrate at high pH as an electron opaque stainin electron-microscopy. J Cell Biol 17: 208–212

    Google Scholar 

  • Ruda MA, Coffield J, Steinbusch HWM (1982) Immunocytochemical analysis of serotonergic axons in laminae I and II of the lumbar spinal cord of the cat. J Neurosci 2: 1660–1671

    Google Scholar 

  • Rye DB, Saper CB, Wainer BH (1984) Stabilisation of tetramethyl benzidine (TMB) reaction product: application for retrograde and anterograde tracing, and combination with immunocytochemistry. J Histochem Cytochem 32: 1154–1153

    Google Scholar 

  • Sano Y, Takeuchi Y, Kimura H, Goto M, Kawata M, Kojima T, Ueda S, Yamada H (1982) Immunohistochemical studies on the processes of serotonin neurons and their ramifications in the central nervous system-with regard to the possibility of the existance of Golgi's rete nervosa diffusa. Arch Histol Jpn 45: 305–316

    Google Scholar 

  • Skagerberg G, Björklund A (1985) Topographic principles in the spinal projections of serotonergic and non-serotonergic brainstem neurons in the rat. Neuroscience 15: 445–480

    Google Scholar 

  • Somogyi P, Hodgson AJ, Smith AD (1979) An aproach to tracing neuron networks in the cerebral cortex and basal ganglia: combination of Golgi staining, retrograde transport of horseradish peroxidase and anterograde degeneration of synaptic boutons in the same material. Neuroscience 4: 1805–1852

    Google Scholar 

  • Steinbusch HWM (1981) Distribution of serotonin-immunoreactivity in the central nervous system of the rat cell bodies and terminals. Neuroscience 6: 557–618

    Google Scholar 

  • Thompson AM, Thompson GC (1988) Neural connections identified with PHA-L anterograde and HRP retrorgade tract-tracing techniques. J Neurosci Meth 25: 13–17

    Google Scholar 

  • Torvik A, Brodal A (1957) The origin of reticulospinal fibres in the cat: an experimental study. Anat Rec 128: 113–137

    Google Scholar 

  • Ward DG, Gunn CG (1976) Locus couruleus complex: Differential modulation of depressor mechanisms. Brain Res 107: 407–411

    Google Scholar 

  • Wouterlood FG (1988) Anterograde neuroanatomical tracing with Phaseolus vulgaris leucoagglutinin combined with immunocytochemistry of gamma-amino butyric acid, choline acetyltransferase or serotonin. Histochemistry 89: 421–428

    Google Scholar 

  • Yen CT, Blum PS, Spath JA Jr (1983) Control of cardiovascular function by electrical stimulation within the medullary raphé region of the cat. Exp Neurol 79: 666–679

    Google Scholar 

  • Zagon A, Bacon SJ, Smith AD (1989) Evidence of a monosynaptic pathway between cells in the caudal raphé nuclei and sympathetic preganglionic neurons in the rat spinal cord. Soc Neurosci Abstr 239.13

  • Zemlan FP, Kow LM, Morrell JL, Pfaff DW (1979) Descending tracts of the lateral column of the rat spinal cord: a study using the horseradish peroxidase and silver intensification techniques. J Anat 128: 489–512

    Google Scholar 

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  1. University Department of Pharmacology, South Parks Road, OX1 3QT, Oxford, UK

    S. J. Bacon, A. Zagon & A. D. Smith

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  1. S. J. Bacon
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Bacon, S.J., Zagon, A. & Smith, A.D. Electron microscopic evidence of a monosynaptic pathway between cells in the caudal raphé nuclei and sympathetic preganglionic neurons in the rat spinal cord. Exp Brain Res 79, 589–602 (1990). https://doi.org/10.1007/BF00229327

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