Anatomy and Embryology

, Volume 207, Issue 3, pp 193–208 | Cite as

Blink-related sensorimotor anatomy in the rat

Original Article


Protection of the eye and maintenance of the precorneal tear film depend on sensory innervation of the cornea and eyelids and motor innervation of muscles involved in closing and opening the eyes. Using a variety of fluorescent and transganglionic tracers, the sensorimotor innervation of blink-related orbital and periorbital structures was studied in Sprague-Dawley rats. The orbicularis oculi muscle surrounded the entire palpebral fissure and was innervated by motoneurons located along the dorsal cap of the ipsilateral facial motor nucleus. Upper and lower eyelid orbicularis oculi motoneurons were strictly ipsilateral and co-extensive, but upper eyelid orbicularis oculi motoneurons were, on average, slightly rostral and lateral to lower eyelid orbicularis oculi motoneurons. Facial motoneurons supplying the frontoscutularis, a muscle that helps to elevate the upper eyelid, were located in the medial division of the ipsilateral facial motor nucleus. Presumptive type Aβ afferents from the cornea terminated most prominently at the junction of the first cervical segment and the spinal trigeminal nucleus, pars caudalis. There was a second concentration of corneal terminations at the junction of pars caudalis and pars interpolaris of the spinal trigeminal nucleus. Sparse projections to the spinal trigeminal nucleus, pars oralis and the principal trigeminal nucleus were also detected. Presumptive type Aβ afferents from the eyelids terminated throughout the rostrocaudal extent of the spinal trigeminal nucleus with a heavy concentration within laminae III and IV of the first cervical segment. Presumptive types Aδ and C terminals from the eyelids were virtually limited to laminae I and II of the first cervical segment. Central terminations from the frontal nerve were present in the principal trigeminal nucleus and throughout the spinal trigeminal nucleus, but were most prominent within the dorsal horn of the first cervical segment. Our comprehensive description of blink-related sensorimotor anatomy in rats will provide a foundation for future physiological studies of blinking.


Trigeminal Orbicularis oculi Motoneurons Cholera toxin Eyelid 


I, II, III, IV and V

spinal cord laminae


facial nucleus

C1, C2 and C3

first, second and third cervical segments


B subunit of cholera toxin






Diaminido Yellow


Fast Flue






levator palpebrae


motor trigeminal nucleus


orbicularis oculi


phosphate buffer


phosphate buffered saline


parvicellular reticular nucleus


principal trigeminal nucleus

R1, R2

first and second components of the blink reflex to supraorbital nerve stimulation


spinal trigeminal tract


spinal trigeminal nucleus

Sp5C, Sp5I, Sp5O

pars caudalis, pars interpolaris, and pars oralis of spinal trigeminal nucleus


wheat germ agglutinin-horseradish peroxidase



This work was supported by grants to M.S.L. from the National Institutes of Health (NEI R01 EY12232), Society for Progressive Supranuclear Palsy, Benign Essential Blepharospasm Research Foundation, and University of Tennessee Medical Group.


  1. Aramideh M, Ongerboer de Visser BW, Koelman JHTM, Speelman JD (1995) Motor persistence of orbicularis oculi muscle in eye-lid-opening disorders. Neurology 45:897–902PubMedGoogle Scholar
  2. Aramideh M, Ongerboer de Visser BW, Koelman JHTM, Majoie CBL, Holstege G (1997) The late blink reflex response abnormality due to lesion of the lateral tegmental field. Brain 120:1685–1692CrossRefPubMedGoogle Scholar
  3. Basso MA, Strecker RE, Evinger C (1993) Midbrain 6-hydroxydopamine lesions modulate blink reflex excitability. Exp Brain Res 94:88–96PubMedGoogle Scholar
  4. Belmonte C, Gallar J, Pozo MA, Rebollo I (1991) Excitation by irritant chemical substances of sensory afferent units in the cat’s cornea. J Physiol 437:709–725PubMedGoogle Scholar
  5. Berardelli A, Cruccu G, Manfredi M, Rothwell JC, Day BL, Marsden CD (1985) The corneal reflex and the R2 component of the blink reflex. Neurology 35:797–801PubMedGoogle Scholar
  6. Bron AJ, Tiffany JM (1998) The meibomian glands and tear film lipids. Structure, function, and control. In: Sullivan DA (eds) Lacrimal gland, tear film, and dry eye syndromes 2: basic and clinical relevance (advances in experimental medicine and biology, 438). Plenum Press, New York, pp 281–295Google Scholar
  7. Doane MG (1980) Interactions of eyelids and tears in corneal wetting and the dynamics of the normal human eyeblink. Am J Ophthalmol 89:507–516PubMedGoogle Scholar
  8. Evinger C, Shaw MD, Peck CK, Manning KA, Baker R (1984) Blinking and associated eye movements in humans, guinea pigs, and rabbits. J Neurophysiol 52:323–339PubMedGoogle Scholar
  9. 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 262:429–445PubMedGoogle Scholar
  10. Faulkner B, Brown TH, Evinger C (1997) Identification and characterization of rat orbicularis oculi motoneurons using confocal laser scanning microscopy. Exp Brain Res 116:10–19PubMedGoogle Scholar
  11. Friauf E (1986) Morphology of motoneurons in different subdivisions of the rat facial nucleus stained intracellularly with horseradish peroxidase. J Comp Neurol 253:231–241PubMedGoogle Scholar
  12. Fuchs AF, Becker W, Ling L, Langer TP, Kaneko CR (1992) Discharge patterns of levator palpebrae superioris motoneurons during vertical lid and eye movements in the monkey. J Neurophysiol 68:233–243PubMedGoogle Scholar
  13. Fujihara T, Murakami T, Fujita H, Nakamura M, Nakata K (2001) Improvement of corneal barrier function by the P2Y(2) agonist INS365 in a rat dry eye model. Invest Ophthalmol Vis Sci 42:96–100PubMedGoogle Scholar
  14. Halata Z, Munger BL (1980) The sensory innervation of primate eyelid. Anat Rec 198:657–670PubMedGoogle Scholar
  15. Hebel R, Stromberg MW (1976) Anatomy of the laboratory rat. Williams and Wilkins, BaltimoreGoogle Scholar
  16. Hinrichsen CFL, Watson CD (1984) The facial nucleus of the rat: representation of facial muscles revealed by retrograde transport of horseradish peroxidase. J Comp Neurol 209:407–415Google Scholar
  17. Hiraoka M, Shimamura M (1977) Neural mechanisms of the corneal blinking reflex in cats. Brain Res 125:265–275CrossRefPubMedGoogle Scholar
  18. Hömig JP (1970) Die Anatomie des aktiven Bewegungsapparates der Al-binoratte (Mus rattus norvegicus albinos). Inaug Diss det Tierärztl Fakultät, MünchenGoogle Scholar
  19. Hoyes AD, Barber P (1976) Ultrastructure of the corneal nerves in the rat. Cell Tissue Res 172:133–144PubMedGoogle Scholar
  20. Jenny AB, Saper CB (1987) Organization of the facial nucleus and corticofacial projection in the monkey: a reconsideration of the upper motor neuron facial palsy. Neurology 37:930–939PubMedGoogle Scholar
  21. Keen MS, Burgoyne JD, Kay SL (1993) Surgical management of the paralyzed eyelid. Ear Nose Throat J 72:692–701PubMedGoogle Scholar
  22. Klein BG, Rhoades RW, Jacquin MF (1990) Topography of the facial musculature within the facial (VII) motor nucleus of the neonatal rat. Exp Brain Res 81:649–653PubMedGoogle Scholar
  23. Kugelberg E (1952) Facial reflexes. Brain 76:385–396Google Scholar
  24. Kume M, Uemura M, Matsuda K, Matsushima R, Mizuno N (1978) Topographical representation of peripheral branches of the facial nerve within the facial nucleus: an HRP study in the cat. Neurosci Lett 8:5–8CrossRefGoogle Scholar
  25. LaMotte CC, Kapadia SE, Shapiro CM (1991) Central projections of the sciatic, saphenous, median, and ulnar nerves of the rat demonstrated by transganglionic transport of choleragenoid-HRP (B-HRP) and wheat germ agglutinin-HRP (WGA-HRP). J Comp Neurol 311:546–562PubMedGoogle Scholar
  26. Lawrenson JG, Ruskell GL (1993) Investigation of limbal touch sensitivity using a Cochet-Bonnet aesthesiometer. Br J Ophthalmol 77:339–343PubMedGoogle Scholar
  27. LeDoux MS, Lorden JF, Weir AD, Smith JM (1997) Blink reflex to supraorbital nerve stimulation in the cat. Exp Brain Res 116:104–112PubMedGoogle Scholar
  28. LeDoux MS, Q Zhou, RB Murphy, ML Greene, P Ryan (2001) Parasympathetic innervation of the Meibomian glands in rats. Invest Ophthalmol Vis Sci 42:2434–2441PubMedGoogle Scholar
  29. Liu H, Llewellyn-Smith IJ, Basbaum AI (1995) Co-injection of wheat germ agglutinin-HRP and choleragenoid-HRP into the sciatic nerve of the rat blocks transganglionic transport. J Histochem Cytochem 43:489–495PubMedGoogle Scholar
  30. Luppi PH, Fort P, Jouvet M (1990) Iontophoretic application of unconjugated cholera toxin B subunit (CTb) combined with immunohistochemistry of neurochemical substances: a method for transmitter identification of retrogradely labeled neurons. Brain Res 534:209–224CrossRefPubMedGoogle Scholar
  31. Marfurt CF (1981) The central projections of trigeminal primary afferent neurons in the cat as determined by the transganglionic transport of horseradish peroxidase. J Comp Neurol 203:785–798PubMedGoogle Scholar
  32. Marfurt CF, Del Toro DR (1987) Corneal sensory pathway in the rat: a horseradish peroxidase tracing study. J Comp Neurol 261:450–459PubMedGoogle Scholar
  33. Marfurt CF, Echtenkamp SF (1988) Central projections and trigeminal ganglion location of corneal afferent neurons in the monkey Macaca fascicularis. J Comp Neurol 272:370–382PubMedGoogle Scholar
  34. Martin MR, Lodge D (1977) Morphology of the facial nucleus in the rat. Brain Res 123:1–12CrossRefPubMedGoogle Scholar
  35. Maslany S, Crockett DP, Egger MD (1992) Organization of cutaneous primary afferent fibers projecting to the dorsal horn in the rat: WGA-HRP versus B-HRP. Brain Res 569:123–135CrossRefPubMedGoogle Scholar
  36. May PJ, Porter JD (1998) The distribution of primary afferent terminals from the eyelids of macaque monkeys. Exp Brain Res 123:368–381CrossRefPubMedGoogle Scholar
  37. Meng ID, Hu JW, Benetti AP, Bereiter DA (1997) Encoding of corneal input in two distinct regions of the spinal trigeminal nucleus in the rat: cutaneous receptive field properties, responses to thermal and chemical stimulation, modulation by diffuse noxious inhibitory controls, and projections to the parabrachial area. J Neurophysiol 77:43–56PubMedGoogle Scholar
  38. Meng ID, Hu JW, Bereiter DA (2000) Parabrachial area and nucleus raphe magnus inhibition of corneal units in rostral and caudal portions of trigeminal subnucleus caudalis in the rat. Pain 87:241–251CrossRefPubMedGoogle Scholar
  39. Morcuende S, Delgado-García J-M, Ugolini G (2002) Neuronal premotor networks involved in eyelid responses: retrograde transneuronal tracing with rabies virus from the orbicularis oculi muscle in rat. J Neurosci 22:8808–8818PubMedGoogle Scholar
  40. Morecraft RJ, Louie JL, Herrick JL, Stilwell-Morecraft KS (2001) Cortical innervation of the facial nucleus in the non-human primate: a new interpretation of the effects of stroke and related subtotal brain trauma on the muscles of facial expression. Brain 124:176–208CrossRefPubMedGoogle Scholar
  41. Muller LJ, Pels L, Vrensen GF (1996) Ultrastructural organization of human corneal nerves. Invest Ophthalmol Vis Sci 37:476–488PubMedGoogle Scholar
  42. Nicholson DA, Freeman JH Jr (2000) Developmental changes in eye-blink conditioning and neuronal activity in the inferior olive. J Neurosci 20:8218–8226PubMedGoogle Scholar
  43. Oda Y (1981) Extraocular muscles and their relationship to the accessory abducens nucleus in rats as studied by the horseradish peroxidase method. Okajimas Folia Anat Jpn 58:43–54PubMedGoogle Scholar
  44. Ongerboer de Visser BW, Kuypers HGJM (1978) Late blink reflex changes in lateral medullary lesions. An electrophysiological and neuro-anatomical study of Wallenberg’s syndrome. Brain 101:285–294PubMedGoogle Scholar
  45. Panneton WM, Burton H (1981) Corneal and periocular representation within trigeminal sensory complex in the cat studied with transganglionic transport of horseradish peroxidase. J Comp Neurol 199:327–344PubMedGoogle Scholar
  46. Paxinos G, Watson C (1998) The rat brain in stereotaxic coordinates, 4th edn. Academic Press, New YorkGoogle Scholar
  47. Pelligrini JJ, Evinger C (1997) Role of cerebellum in adaptive modification of reflex blinks. Exp Brain Res 4:77–87Google Scholar
  48. Pelligrini JJ, Horn AKE, Evinger C (1995) The trigeminally evoked blink reflex. I. Neuronal circuits. Exp Brain Res 107:166–180PubMedGoogle Scholar
  49. Porter JD, Burns LA, May PJ (1989) Morphological substrate for eyelid movements: innervation and structure of primate levator palpebrae superioris and orbicularis oculi muscles. J Comp Neurol 287:64–81PubMedGoogle Scholar
  50. Powers AS, Schicatano EJ, Basso MA, Evinger C (1997) To blink or not to blink: inhibition and facilitation of reflex blinks. Exp Brain Res 113:283–290PubMedGoogle Scholar
  51. Price DD, Dubner R, Hu JW (1976) Trigeminothalamic neurons in nucleus caudalis responsive to tactile, thermal, and nociceptive stimulation of monkey’s face. J Neurophysiol 39:936–953PubMedGoogle Scholar
  52. Robertson B, Arvidsson J (1985) Transganglionic transport of wheat germ agglutinin-HRP and choleragenoid-HRP in rat trigeminal primary sensory neurons. Brain Res 348:44–51CrossRefPubMedGoogle Scholar
  53. Robertson B, Grant GA (1985) A comparison between WGA-HRP and choleragenoid-HRP as anterogradely transported markers in central branches of primary sensory neurones in the rat with some observations in the cat. Neuroscience 14:895–905PubMedGoogle Scholar
  54. Sahlin S, Chen E, Kaugesaar T, Almqvist H, Kjellberg K, Lennerstrand G (2000) Effect of eyelid botulinum toxin injection on lacrimal drainage. Am J Ophthalmol 129:481–486CrossRefPubMedGoogle Scholar
  55. Schicatano EJ, Basso MA, Evinger C (1997) Animal model explains the origins of the cranial dystonia benign essential blepharospasm. J Neurophysiol 77:2842–2846PubMedGoogle Scholar
  56. Schicatano EJ, Peshori KR, Gopalaswamy R, Sahay E, Evinger C (2000) Reflex excitability regulates prepulse inhibition. J Neurosci 20:4240–4247PubMedGoogle Scholar
  57. Shahani B (1970) The human blink reflex. J Neurol Neurosurg Psychiatry 33:792–800PubMedGoogle Scholar
  58. Shigenaga Y, Chen IC, Suemune S, Nishimori T, Nasution ID, Yoshida A, Sato H, Okamoto T, Sera M, Hosoi M (1986a) Oral and facial representation within the medullary and upper cervical dorsal horns in the cat. J Comp Neurol 243:388–408PubMedGoogle Scholar
  59. Shigenaga Y, Okamoto T, Nishimori T, Suemune S, Nasution ID, Chen IC, Tsuru K, Yoshida A, Tabuchi K, Hosoi M, et al (1986b) Oral and facial representation in the trigeminal principal and rostral spinal nuclei of the cat. J Comp Neurol 244:1–18PubMedGoogle Scholar
  60. Shore JW (1985) Changes in lower eyelid resting position, movement, and tone with age. Am J Ophthalmol 99:415–423PubMedGoogle Scholar
  61. Simons E, Smith PG (1994) Sensory and autonomic innervation of the rat eyelid: neuronal origins and peptide phenotypes. J Chem Neuroanat 7:35–47CrossRefPubMedGoogle Scholar
  62. Tabachnick BG, Fidell LS (1989) Using Multivariate Statistics, 2nd edn. Harper Row, New YorkGoogle Scholar
  63. Takemura M, Sugimoto T, Shigenaga Y (1991) Difference in central projection of primary afferents innervating facial and intraoral structures in the rat. Exp Neurol 111:324–331PubMedGoogle Scholar
  64. Tamai Y, Iwamoto M, Tsujimoto T (1986) Pathway of the blink reflex in the brainstem of the cat: interneurons between the trigeminal nuclei and the facial nucleus. Brain Res 380:19–25CrossRefPubMedGoogle Scholar
  65. Thanos PK, Terzis JK (1995) Motor endplate analysis of the denervated and reinnervated orbicularis oculi muscle in the rat. J Reconstr Microsurg 11:423–428PubMedGoogle Scholar
  66. Tokunaga A, Oka M, Murao T, Yokoi H, Okumura T, Hirata T, Miyashita Y, Yoshitatsu S (1958) An experimental study on facial reflex by evoked electromyography. Med J Osaka Univ 9:397–411Google Scholar
  67. Travers JB (1995) Oromotor nuclei. In: Paxinos G (ed) The rat nervous system, 2nd edn. Academic Press, San Diego, pp 239–255Google Scholar
  68. Ugolini G (1992) Transneuronal transfer of herpes simplex virus 1 (HSV 1) from mixed limb nerves to the CNS. I. Sequence of transfer from sensory, motor, and sympathetic nerve fibres to the spinal cord. J Comp Neurol 22:527–548Google Scholar
  69. VanderWerf F, Aramideh M, Otto JA, Ongerboer de Visser BW (1998) Retrograde tracing studies of subdivisions of the orbicularis oculi muscle in the rhesus monkey. Exp Brain Res 121:433–441CrossRefPubMedGoogle Scholar
  70. van Ham JJ, Yeo CH (1996) The central distribution of primary afferents from the external eyelids, conjunctiva, and cornea in the rabbit, studied using WGA-HRP and B-HRP as transganglionic tracers. Exp Neurol 142:217–225CrossRefPubMedGoogle Scholar
  71. Weiss C, Thompson RF (1991) The effects of age on eyeblink conditioning in the freely moving Fisher-344 rat. Neurobiol Aging 12:249–254CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag 2003

Authors and Affiliations

  1. 1.Department of NeurologyUniversity of Tennessee Health Science CenterMemphisUSA
  2. 2.Department of Anatomy and NeurobiologyUniversity of Tennessee Health Science CenterMemphisUSA

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