Experimental Brain Research

, Volume 84, Issue 3, pp 525–528

Antidromic identification of midbrain near response cells projecting to the oculomotor nucleus

  • Y. Zhang
  • P. D. R. Gamlin
  • L. E. Mays
Article

Summary

Medial rectus motoneurons carry both conjugate and vergence eye position signals. Abducens internuclear neurons, whose axons travel in the medial longitudinal fasciculus, provide these motoneurons with the major signal for conjugate eye movements but not for vergence eye movements. A vergence signal appropriate for these motoneurons is seen on the near response cells that are found in the mesencephalic reticular formation within 2 mm of the oculomotor nucleus. The goal of the present study was to determine if midbrain near response cells project to the medial rectus subdivision of the oculomotor nucleus. Near response cells were recorded in two trained rhesus monkeys with ocular search coils. A stimulating electrode was positioned within the medial rectus subdivision of the oculomotor nucleus. Twenty-eight near response cells were found that could be driven by single pulse microstimulation of the ipsilateral medial rectus subdivision. In all cases, antidromic activation was confirmed by collision testing. Attempts to antidromically activate midbrain near response cells from the contralateral medial rectus subdivision were unsuccessful. Most antidromically activated cells had a steady state firing rate proportional to vergence angle. One cell also showed burst activity during the vergence eye movements. Divergence cells were not antidromically activated.

Key words

Convergence Oculomotor Midbrain Antidromic stimulation Monkey 

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References

  1. Büttner-Ennever JA, Akert K (1981) Medial rectus subgroups of the oculomotor nucleus and their abducens internuclear input in the monkey. J Comp Neurol 197: 17–27Google Scholar
  2. Carpenter MB, Batton RR (1980) Abducens internuclear neurons and their role in conjugate horizontal gaze. J Comp Neurol 189: 191–209Google Scholar
  3. Evinger LC, Fuchs AF, Baker R (1977) Bilateral lesions of the medial longitudinal fasciculus in monkeys: effects on horizontal and vertical components of voluntary and vestibular induced eye movements. Exp Brain Res 28: 1–20Google Scholar
  4. Fuchs AF, Kaneko CRS, Scudder CA (1985) Brainstem control of saccadic eye movements. Ann Rev Neurosci 8: 307–337Google Scholar
  5. Fuchs AF, Robinson DA (1966) A method for measuring horizontal and vertical eye movement chronically in the monkey. J Appl Physiol 21: 1068–1070PubMedGoogle Scholar
  6. Gamlin PDR, Mays LE (1986) Medial rectus motoneurons carry a vergence velocity signal in addition to a vergence position signal. Soc Neurosci Abstr p 460Google Scholar
  7. Gamlin PDR, Gnadt JW, Mays LE (1989a) Abducens internuclear neurons carry an inappropriate signal for ocular convergence. J Neurophysiol 62: 70–81Google Scholar
  8. Gamlin PDR, Gnadt JW, Mays LE (1989b) Lidocaine-induced unilateral internuclear ophthalmoplegia: effects on convergence and conjugate eye movements. J Neurophysiol 62: 82–95Google Scholar
  9. Graybiel AM, Hartweig EA (1974) Some afferent connections of the oculomotor complex in the cat: an experimental study with tracer techniques. Brain Res 81: 543–551Google Scholar
  10. Highstein SM, Baker R (1978) Excitatory termination of abducens internuclear neurons on medial rectus motoneurons: relationship to syndrome of internuclear ophthalmoplegia. J Neurophysiol 41: 1647–1661Google Scholar
  11. Judge SJ, Cumming BG (1986) Neurons in the monkey midbrain with activity related to vergence eye movement and accommodation. J Neurophysiol 55: 915–930Google Scholar
  12. Mays LE (1984) Neural control of vergence eye movements: convergence and divergence neurons in midbrain. J Neurophysiol 51: 1091–1108Google Scholar
  13. Mays LE, Porter JD (1984) Neural control of vergence eye movements: activity of abducens and oculomotor neurons. J Neurophysiol 52: 743–761Google Scholar
  14. Mays LE, Porter JD, Gamlin PDR, and Tello CA (1986) Neural control of vergence eye movements: neurons encoding vergence velocity. J Neurophysiol 56: 1007–1021Google Scholar
  15. Nakao S, Shiraishi Y, Miraya T (1986) Direct projection of cat midbrain tegmentum neurons to the medial rectus subdivision of the oculomotor complex. Neurosci Lett 64: 123–128Google Scholar
  16. Smith JL, Cogan DG (1959) Internuclear ophthalmoplegia. a review of 58 cases. Arch Ophthalmol 61: 687–694Google Scholar

Copyright information

© Springer-Verlag 1991

Authors and Affiliations

  • Y. Zhang
    • 1
  • P. D. R. Gamlin
    • 1
  • L. E. Mays
    • 1
    • 2
  1. 1.Department of Physiological OpticsSchool of Optometry, University of Alabama at BirminghamBirminghamUSA
  2. 2.Neurobiology Research Center, University of Alabama at BirminghamBirminghamUSA

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