The potential role of extraocular muscle proprioception in the neural control of eye movements has been obscure. Although the pattern of sensory and motor neuronal innervation of these muscles has been elucidated, relatively little is known regarding the central and peripheral terminations of the extraocular muscle sensory neurones and the types of muscle fibers with which they are associated.
The specific aims of the proposed studies are directed toward elucidating the central and peripheral anatomical structures that underlie extraocular muscle sensory innervation in the monkey using light and electron microscopy. The pattern of central synaptic connections of first order muscle sensory neurons will be determined by transganglionic transport of wheat germ agglutinin-conjugated horseradish peroxidase (WGA/HRP). Secondly, these studies will label the sensory nerve terminals with WSA/HRP, transported anterograde from the site of the first order neurons (i.e., semilunar ganglion), in order to inequivocally localize and characterize extraocular muscle sensory receptors. The proposed studies also provide a unique opportunity to examine sensory-motor interactions in the primate oculomotor system. Reciprocal communications between mononeurons and the muscle fibers they innervate serves to maintain the integrity of each of these components of the motor unit. Similarly, trophic interactions may exist between sensory nerve terminals and the particular muscle fiber types with which they are associated. The proposed studies will examine sequential changes in individual exraocular muscle fiber types subsequent to either sensory or motor denervation of the extraocular muscles. Taken together, the proposed studies will begin to define the sensory and motor neuronal interactions that occur peripherally in the oculomotor system. Our long-term goal is to utilize the information obtained from these morhological analyses, combined with the physiological evaluation of functional status using an alert monkey model, in order to comprehend the peripheral changes subsequent to experimentally-induced oculomotor dysfunction.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY005464-03
Application #
3260547
Study Section
Visual Sciences B Study Section (VISB)
Project Start
1984-07-01
Project End
1987-06-30
Budget Start
1986-07-01
Budget End
1987-06-30
Support Year
3
Fiscal Year
1986
Total Cost
Indirect Cost
Name
University of Mississippi Medical Center
Department
Type
Schools of Medicine
DUNS #
928824473
City
Jackson
State
MS
Country
United States
Zip Code
39216
May, P J; Porter, J D (1998) The distribution of primary afferent terminals from the eyelids of macaque monkeys. Exp Brain Res 123:368-81
Horn, A K; Porter, J D; Evinger, C (1993) Botulinum toxin paralysis of the orbicularis oculi muscle. Types and time course of alterations in muscle structure, physiology and lid kinematics. Exp Brain Res 96:39-53
Porter, J D; Baker, R S (1992) Prenatal morphogenesis of primate extraocular muscle: neuromuscular junction formation and fiber type differentiation. Invest Ophthalmol Vis Sci 33:657-70
May, P J; Porter, J D; Gamlin, P D (1992) Interconnections between the primate cerebellum and midbrain near-response regions. J Comp Neurol 315:98-116
May, P J; Porter, J D (1992) The laminar distribution of macaque tectobulbar and tectospinal neurons. Vis Neurosci 8:257-76
Porter, J D; Strebeck, S; Capra, N F (1991) Botulinum-induced changes in monkey eyelid muscle. Comparison with changes seen in extraocular muscle. Arch Ophthalmol 109:396-404
Porter, J D; Donaldson, I M (1991) The anatomical substrate for cat extraocular muscle proprioception. Neuroscience 43:473-81
May, P J; Hartwich-Young, R; Nelson, J et al. (1990) Cerebellotectal pathways in the macaque: implications for collicular generation of saccades. Neuroscience 36:305-24
Porter, J D; Burns, L A; May, P J (1989) Morphological substrate for eyelid movements: innervation and structure of primate levator palpebrae superioris and orbicularis oculi muscles. J Comp Neurol 287:64-81
Porter, J D; Burns, L A; McMahon, E J (1989) Denervation of primate extraocular muscle. A unique pattern of structural alterations. Invest Ophthalmol Vis Sci 30:1894-908

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