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Electrophysiological and morphological properties of rat abducens motoneurones

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The electrical and morphological properties of abducens motoneurones were investigated in the rat with intracellular recordings and intracellular HRP-staining. Motoneurones were identified by their antidromic response to electrical stimulation of the lateral rectus muscle. The antidromic action potential was followed by a delayed depolarization and an after hyperpolarization lasting 20 ms to 45 ms. The whole neurone input resistance (RN) calculated from I/V curves, was found to lie between 2 MΩ and 15 MΩ with a bimodal distribution (mean values 4.9 MΩ and 12 MΩ). In some cases, anomalous rectification was observed with low current intensities. Prolonged hyperpolarizing current pulses revealed the presence of a time dependant inward rectification and slow rebound depolarization. The intensity/frequency curves suggest the existence of three ranges of discharge. The average intensity frequency slope during the steady state was 43 imp/s/ nA. Eight abducens motoneurones were intracellularly labelled with HRP and fully reconstructed. The soma (23 μm to 40 μm in diameter) gave off 5 to 7 primary dendrites. The general organization and extension of the dendritic trees depended on the location of the soma within the abducens nucleus. The mean diameter of primary dendrites was 4.17 μm with similar average values in all motoneurones. The soma size of abducens motoneurones was not correlated with either the size of the proximal tree or the whole neurone input resistance.

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References

  • Baker R, Precht W (1972) Electrophysiological properties of trochlear motoneurones as revealed by IVth nerve stimulation. Exp Brain Res 14: 127–157

    Google Scholar 

  • Baldissera F, Gustafsson B (1974) Firing behaviour of a neuron model based on the after hyperpoiarization conductance time course: first interval firing. Acta Physiol Scand 91: 528–544

    Google Scholar 

  • Barmack NH (1974) Saccadic discharges evoked by intracellular stimulation of extraocular motoneurons. J Neurophysiol 37: 395–412

    Google Scholar 

  • Bradley K, Somjen GG (1961) Accomodation in motoneurones of the rat and the cat. J Physiol (Lond) 156: 75–92

    Google Scholar 

  • Bras H, Gogan P, Tyc-Dumont S (1987) The dendrites of single brain-stem motoneurons intracellularly labelled with horse-radish peroxidase in the cat: morphological and electrical differences. Neuroscience 22: 947–970

    Google Scholar 

  • Cabrera B, Portillo F, Pasaro R, Delgado-Garcia JM (1988) Location of motoneurons and internuclear neurons within the rat abducens nucleus by means of horseradish peroxidase and fluorescent double labeling. Neurosci Lett 87: 1–6

    Google Scholar 

  • Coombs JS, Eccles JC, Fatt P (1955) The electrical properties of the motoneurone membrane. J Physiol (Lond) 130: 291–325

    Google Scholar 

  • Destombes J, Gogan P, Rouviere A (1979) The fine structure of neurones and cellular relationships in the abducens nucleus in the cat. Exp Brain Res 35: 249–267

    Google Scholar 

  • Eccles JC, Eccles RM, Lundberg A (1958) The action potentials of alpha motoneurones supplying fast and slow muscles. J Physiol (Lond) 142: 275–291

    Google Scholar 

  • Evinger C, Baker R, Spencer RF (1982) Comparison of oculomotor motoneuron axon collaterals in mammals. In: Lennerstrand G, Zee DS, Keller EL (eds) Functional basis of ocular motility disorders. Pergamon Press, Oxford, pp 531–533

    Google Scholar 

  • Evinger C, Graf WM, Baker R (1987) Extra-and intracellular HRP analysis of the organization of extraocular motoneurons and internuclear neurons in the guinea pig and rabbit. J Comp Neurol 262: 429–445

    Google Scholar 

  • Glicksman MA (1980) Localization of motoneurons controlling the extraocular muscles of the rat. Brain Res 188: 53–62

    Google Scholar 

  • Gogan P, Gueritaud JP, Horcholle-Bossavit G, Tyc-Dumont S (1974) Electrotonic coupling between motoneurones in the abducens nucleus of the cat. Exp Brain Res 21: 139–154

    Google Scholar 

  • Gogan P, Gueritaud JP, Horcholle-Bossavit G, Tyc-Dumont S (1981) The vibrissal pad as a source of sensory information for the oculomotor system of the cat. Exp Brain Res 44: 409–418

    Google Scholar 

  • Granit R (1964) Maintained firing of motoneurones during transmembrane stimulation. Prog Brain Res 12: 35–41

    Google Scholar 

  • Granit R, Kernell D, Shortess GK (1963) Quantitative aspects of repetitive firing of mammalian motoneurones caused by injected currents. J Physiol (Lond) 168: 911–931

    Google Scholar 

  • Granit R, Kernell D, Smith RS (1963) Delayed depolarization and the repetitive response to intracellular stimulation of mammalian motoneurones. J Physiol (Lond) 168: 890–910

    Google Scholar 

  • Grant K, Gueritaud JP, Horcholle-Bossavit G, Tyc-Dumont S (1979) Morphological characteristics of lateral rectus motoneurones shown by intracellular injection of HRP. J Physiol (Paris) 75: 513–519

    Google Scholar 

  • Grantyn R, Grantyn A, Schaaf P (1977) Conduction velocity input resistance and size of cat ocular motoneurones stained with procion yellow. Brain Res 135: 167–173

    Google Scholar 

  • Grantyn R, Grantyn A (1978) Morphological and electrophysiological properties of cat abducens motoneurones. Exp Brain Res 31: 249–274

    Google Scholar 

  • Gueritaud JP (1988) Electrical activity of rat ocular motoneurons recorded in vitro. Neuroscience 24: 837–852

    Google Scholar 

  • Gustafsson B (1974) Afterhyperpolarization and the control of repetitive firing in spinal motoneurones of the cat. Acta Physiol Scand Suppl 92: 416

    Google Scholar 

  • Hanker JS, Yates PE, Metz CB, Rustioni A (1977) A new specific, sensitive and non carcinogenic reagent for the demonstration of horseradish peroxidase. Histochem J 9: 789–792

    Google Scholar 

  • Kernell D (1964) The delayed depolarization in cat and rat motoneurones. Prog Brain Res 12: 42–55

    Google Scholar 

  • Kernell D (1965) The adaptation and the relation between discharge frequency and current strength of cat lumbosacral motoneurones stimulated by long-lasting injected currents. Acta Physiol Scand 65: 65–73

    Google Scholar 

  • Labandeira Garcia JL, Gomez-Seijas MJG, Segade LAG, Suarez-Numez JM (1983) Localisation of motoneurons supplying the extra-ocular muscles of the rat using horseradish peroxidase and fluorescent double labelling. J Anat 137: 247–261

    Google Scholar 

  • McCrea RA, Strassman A, Highstein SM (1986) Morphology and physiology of abducens motoneurons and internuclear neurons intracellularly injected with horseradish peroxidase in alert squirrel monkeys. J Comp Neurol 243: 291–308

    Google Scholar 

  • Nelson PG, Burke RE (1967) Delayed depolarization in cat spinal motoneurons. Exp Neurol 17: 16–26

    Google Scholar 

  • Purves D, Lichtman JW (1985) Geometrical differences among homologous neurons in mammals. Science 228: 298–302

    Google Scholar 

  • Purves D, Madley RD, Voyvodic J (1986) Dynamic changes in the dendritic geometry of individual neurons visualized over periods of up to three months in the superior cervical ganglion of living mice. J Neurosci 6: 1051–1060

    Google Scholar 

  • Rose PK, Keirstead SA, Vanner SJ (1985) A quantitative analysis of the geometry of cat motoneurons innervating neck and shoulder muscles. J Comp Neurol 239: 89–107

    Google Scholar 

  • Russel-Morgenthal H, McClung JR, Goldberg SJ (1986) The determination of dendrite morphology on lateral rectus motoneurons in cat. J Comp Neurol 245: 116–122

    Google Scholar 

  • Sasaki K (1963) Electrophysiological studies on oculomotor neurons of the cat. Jpn J Physiol 13: 297–302

    Google Scholar 

  • Schwindt PC, Calvin WH (1972) Membrane potential trajectories between spikes underlying motoneuron firing rates. J Neurophysiol 35: 311–325

    Google Scholar 

  • Spain WJ, Schwindt PC, Crill WE (1987) Anomalous rectification in neurons from cat sensorimotor cortex in vitro. J Neurophysiol 57: 1555–1576

    Google Scholar 

  • Spencer RF, Sterling P (1977) An electron microscope study of motoneurones and interneurones in the cat abducens nucleus identified by retrograde intraaxonal transport of horseradish peroxidase. J Comp Neurol 176: 65–86

    Google Scholar 

  • Szekely G, Matesz C (1982) The accessory motor nuclei of the trigeminal, facial, and abducens nerves in the rat. J Comp Neurol 210: 258–264

    Google Scholar 

  • Thompson D (1961) On growth and form. Cambridge University Press, Cambridge

    Google Scholar 

  • Ulfhake B (1984) A morphological study of the soma, first order dendrites and proximal axon of cat lumbar γ-motoneurones intracellularly labelled with HRP. Exp Brain Res 56: 327–334

    Google Scholar 

  • Ulfhake B, Cullheim S (1981) A quantitative light microscopic study of the dendrites of cat spinal γ-motoneurons after intracellular staining with horseradish peroxidase. J Comp Neurol 202: 585–596

    Google Scholar 

  • Ulfhake B, Kellerth JO (1981) A quantitative light microscopic study of dendrites of cat spinal α-motoneurons after intracellular staining with horseradish peroxidase. J Comp Neurol 202: 571–583

    Google Scholar 

  • Ulfhake B, Kellerth JO (1983) A quantitative morphological study of HRP-labelled cat α-motoneurones supplying different hindlimb muscles. Brain Res 264: 1–20

    Google Scholar 

  • Ulfhake B, Kellerth JO (1984) Electrophysiological and morphological measurements in cat gastrocnemius and soleus α- motoneurons. Brain Res 307: 167–179

    Google Scholar 

  • Zwaagstra B, Kernell D (1981) Sizes of soma and stem dendrites in intracellularly labelled a-motoneurones of the cat. Brain Res 204: 295–309

    Google Scholar 

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Durand, J. Electrophysiological and morphological properties of rat abducens motoneurones. Exp Brain Res 76, 141–152 (1989). https://doi.org/10.1007/BF00253631

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