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Volumn 88, Issue 2, 2010, Pages 290-303

Identification of vestibuloocular projection neurons in the developing chicken medial vestibular nucleus

Author keywords

Extracellular biocytin dye; Retrograde dye transport; Vestibuloocular reflex neurons

Indexed keywords

BIOCYTIN;

EID: 74049158308     PISSN: 03604012     EISSN: 10974547     Source Type: Journal    
DOI: 10.1002/jnr.22206     Document Type: Article
Times cited : (16)

References (61)
  • 2
    • 0025752677 scopus 로고
    • Organization of the cerebellum in the pigeon (Columba livia): III. Corticovestibular connections with eye and neck premotor areas
    • Arends JJA, Allan RW, Zeigler HP. 1991. Organization of the cerebellum in the pigeon (Columba livia): III. Corticovestibular connections with eye and neck premotor areas. J Comp Neurol 306:273-289.
    • (1991) J Comp Neurol , vol.306 , pp. 273-289
    • Arends, J.J.A.1    Allan, R.W.2    Zeigler, H.P.3
  • 3
    • 40249086711 scopus 로고    scopus 로고
    • Dendrodendritic and dendrosomatic contacts between oculomotor and trochlear motoneurons of the frog, Rana esculenta
    • Bacskai T, Veress G, Halasi G, Deak A, Racz E, Szekely G, Matesz C. 2008. Dendrodendritic and dendrosomatic contacts between oculomotor and trochlear motoneurons of the frog, Rana esculenta. Brain Res Bull 75:419-423.
    • (2008) Brain Res Bull , vol.75 , pp. 419-423
    • Bacskai, T.1    Veress, G.2    Halasi, G.3    Deak, A.4    Racz, E.5    Szekely, G.6    Matesz, C.7
  • 4
    • 33847341614 scopus 로고    scopus 로고
    • Transgenic mouse lines subdivide medial vestibular nucleus neurons into discrete, neurochemically distinct populations
    • Bagnall MW, Stevens RJ, du Lac S. 2007. Transgenic mouse lines subdivide medial vestibular nucleus neurons into discrete, neurochemically distinct populations. J Neurosci 27:2318-2330.
    • (2007) J Neurosci , vol.27 , pp. 2318-2330
    • Bagnall, M.W.1    Stevens, R.J.2    du Lac, S.3
  • 5
    • 0023837408 scopus 로고
    • Anatomical connections of the prepositus and abducens nuclei in the squirrel monkey
    • Belknap DB, McCrea RA. 1988. Anatomical connections of the prepositus and abducens nuclei in the squirrel monkey. J Comp Neurol 268:13-28.
    • (1988) J Comp Neurol , vol.268 , pp. 13-28
    • Belknap, D.B.1    McCrea, R.A.2
  • 6
    • 0026768131 scopus 로고
    • Inputs from regularly and irregularly discharging vestibular nerve afferents to secondary neurons in squirrel monkey vestibular nuclei. III. Correlation with vestibulospinal and vestibuloocular output pathways
    • Boyle R, Goldberg JM, Highstein SM. 1992. Inputs from regularly and irregularly discharging vestibular nerve afferents to secondary neurons in squirrel monkey vestibular nuclei. III. Correlation with vestibulospinal and vestibuloocular output pathways. J Neurophysiol 68:471-484.
    • (1992) J Neurophysiol , vol.68 , pp. 471-484
    • Boyle, R.1    Goldberg, J.M.2    Highstein, S.M.3
  • 7
    • 0029974655 scopus 로고    scopus 로고
    • Connections with connexins: The molecular basis of direct intercellular signaling
    • Bruzzone R, White TW, Paul DL. 1996. Connections with connexins: the molecular basis of direct intercellular signaling. Eur J Biochem 238:1-27.
    • (1996) Eur J Biochem , vol.238 , pp. 1-27
    • Bruzzone, R.1    White, T.W.2    Paul, D.L.3
  • 8
    • 0025336951 scopus 로고
    • Horseradish peroxidase labeling of the efferent and afferent pathways of the avian tangential vestibular nucleus
    • Cox RG, Peusner KD. 1990. Horseradish peroxidase labeling of the efferent and afferent pathways of the avian tangential vestibular nucleus. J Comp Neurol 296:324-341.
    • (1990) J Comp Neurol , vol.296 , pp. 324-341
    • Cox, R.G.1    Peusner, K.D.2
  • 9
    • 33846611481 scopus 로고    scopus 로고
    • A monosynaptic pathway links the vestibular nuclei and masseter muscle motoneurons in rats
    • Cuccurazzu B, Deriu F, Tolu E, Yates BJ, Billig I. 2007. A monosynaptic pathway links the vestibular nuclei and masseter muscle motoneurons in rats. Exp Brain Res 176:665-671.
    • (2007) Exp Brain Res , vol.176 , pp. 665-671
    • Cuccurazzu, B.1    Deriu, F.2    Tolu, E.3    Yates, B.J.4    Billig, I.5
  • 10
    • 0037012228 scopus 로고    scopus 로고
    • Comparative aspects of the hodological organization of the vestibular nuclear complex and related neuron populations
    • Diaz C, Glover JC. 2002. Comparative aspects of the hodological organization of the vestibular nuclear complex and related neuron populations. Brain Res Bull 57:307-312.
    • (2002) Brain Res Bull , vol.57 , pp. 307-312
    • Diaz, C.1    Glover, J.C.2
  • 11
    • 0021242024 scopus 로고
    • Increased projection of ascending dorsal root fibers to vestibular nuclei after hemilabyrinthectomy in the frog
    • Dieringer N, Kunzle H, Precht W. 1984. Increased projection of ascending dorsal root fibers to vestibular nuclei after hemilabyrinthectomy in the frog. Exp Brain Res 55:574-578.
    • (1984) Exp Brain Res , vol.55 , pp. 574-578
    • Dieringer, N.1    Kunzle, H.2    Precht, W.3
  • 12
    • 0023200068 scopus 로고
    • Extra- and intracellular HRP analysis of the organization of extraocular motoneurons and internuclear neurons in the guinea pig and rabbit
    • 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.
    • (1987) J Comp Neurol , vol.262 , pp. 429-445
    • Evinger, C.1    Graf, W.M.2    Baker, R.3
  • 13
    • 0028484691 scopus 로고
    • A physiological and structural study of neuron types in the cochlear nucleus. I. Intracellular responses to acoustic stimulation and current injection
    • Feng JJ, Kuwada S, Ostapoff EM, Batra R, Morest DK. 1994. A physiological and structural study of neuron types in the cochlear nucleus. I. Intracellular responses to acoustic stimulation and current injection. J Comp Neurol 346:1-18.
    • (1994) J Comp Neurol , vol.346 , pp. 1-18
    • Feng, J.J.1    Kuwada, S.2    Ostapoff, E.M.3    Batra, R.4    Morest, D.K.5
  • 14
    • 0033800656 scopus 로고    scopus 로고
    • Effects of deafferentation on the electrophysiology of ventral cochlear nucleus neurons
    • Francis HW, Manis PB. 2000. Effects of deafferentation on the electrophysiology of ventral cochlear nucleus neurons. Hearing Res 149:91-105.
    • (2000) Hearing Res , vol.149 , pp. 91-105
    • Francis, H.W.1    Manis, P.B.2
  • 15
    • 0000120569 scopus 로고
    • The optokinetic basis of head-bobbing in the pigeon
    • Frost BJ. 1978. The optokinetic basis of head-bobbing in the pigeon. J Exp Biol 74:187-195.
    • (1978) J Exp Biol , vol.74 , pp. 187-195
    • Frost, B.J.1
  • 16
    • 1642417625 scopus 로고    scopus 로고
    • The development of vestibulo-ocular circuitry in the chicken embryo
    • Glover JC. 2003. The development of vestibulo-ocular circuitry in the chicken embryo. J Physiol 97:17-23.
    • (2003) J Physiol , vol.97 , pp. 17-23
    • Glover, J.C.1
  • 17
    • 0022481172 scopus 로고
    • Morphology of vertical canal related second order vestibular neurons in the cat
    • Graf W, Ezure K. 1986. Morphology of vertical canal related second order vestibular neurons in the cat. Exp Brain Res 63:35-48.
    • (1986) Exp Brain Res , vol.63 , pp. 35-48
    • Graf, W.1    Ezure, K.2
  • 18
    • 84924926133 scopus 로고
    • A series of normal stages in the development of chick embryo
    • Hamburger V, Hamilton H. 1951. A series of normal stages in the development of chick embryo. J Morphol 88:49-92.
    • (1951) J Morphol , vol.88 , pp. 49-92
    • Hamburger, V.1    Hamilton, H.2
  • 19
    • 26444582305 scopus 로고    scopus 로고
    • The anatomy of the vestibular nuclei
    • Highstein SM, Holstein GR. 2005. The anatomy of the vestibular nuclei. Prog Brain Res 151:157-203.
    • (2005) Prog Brain Res , vol.151 , pp. 157-203
    • Highstein, S.M.1    Holstein, G.R.2
  • 20
    • 0020641141 scopus 로고
    • Brain stem projections to the facial nucleus of the rat
    • Hinrichsen CFL, Watson CD. 1983. Brain stem projections to the facial nucleus of the rat. Brain Behav Evol 22:153-163.
    • (1983) Brain Behav Evol , vol.22 , pp. 153-163
    • Hinrichsen, C.F.L.1    Watson, C.D.2
  • 21
    • 0023920928 scopus 로고
    • Axonal trajectories of posterior canal-activated secondary vestibular neurons and their coactivation of extraocular and neck flexor motoneurons in the cat
    • Isu N, Uchino Y, Nakashima H, Satoh S, Ichikawa T, Watanabe S. 1988. Axonal trajectories of posterior canal-activated secondary vestibular neurons and their coactivation of extraocular and neck flexor motoneurons in the cat. Exp Brain Res 70:181-191.
    • (1988) Exp Brain Res , vol.70 , pp. 181-191
    • Isu, N.1    Uchino, Y.2    Nakashima, H.3    Satoh, S.4    Ichikawa, T.5    Watanabe, S.6
  • 23
    • 84981860278 scopus 로고
    • Correlation of the development of the membranous and bony labyrinths, acoustic ganglia, nerves and brain centers of the chick embryo
    • Knowlton VY. 1967. Correlation of the development of the membranous and bony labyrinths, acoustic ganglia, nerves and brain centers of the chick embryo. J Morph 121:179-208.
    • (1967) J Morph , vol.121 , pp. 179-208
    • Knowlton, V.Y.1
  • 25
    • 0023132913 scopus 로고
    • Identification of abducens motoneurons, accessory abducens motoneurons, and abducens internuclear neurons in the chick by retrograde transport of horseradish peroxidase
    • Labandeira-Garcia JL, Guerra-Seijas MJ, Segade LAG, Suarez-Nuñez JM. 1987. Identification of abducens motoneurons, accessory abducens motoneurons, and abducens internuclear neurons in the chick by retrograde transport of horseradish peroxidase. J Comp Neurol 259:140-149.
    • (1987) J Comp Neurol , vol.259 , pp. 140-149
    • Labandeira-Garcia, J.L.1    Guerra-Seijas, M.J.2    Segade, L.A.G.3    Suarez-Nuñez, J.M.4
  • 29
    • 0030560677 scopus 로고    scopus 로고
    • The use of in vitro preparations of the isolated amphibian central nervous system in neuroanatomy and electrophysiology
    • Luksch H, Walkowiak W, Monoz A, ten Donkelaar HJ. 1996. The use of in vitro preparations of the isolated amphibian central nervous system in neuroanatomy and electrophysiology. J Neurosci Methods 70:91-102.
    • (1996) J Neurosci Methods , vol.70 , pp. 91-102
    • Luksch, H.1    Walkowiak, W.2    Monoz, A.3    ten Donkelaar, H.J.4
  • 30
    • 0019160143 scopus 로고
    • Eye movement related activity and morphology of second order vestibular neurons terminating in the cat abducens nucleus
    • McCrea RA, Yoshida K, Berthoz A, Baker R. 1980. Eye movement related activity and morphology of second order vestibular neurons terminating in the cat abducens nucleus. Exp Brain Res 40:468-473.
    • (1980) Exp Brain Res , vol.40 , pp. 468-473
    • McCrea, R.A.1    Yoshida, K.2    Berthoz, A.3    Baker, R.4
  • 31
    • 0025696075 scopus 로고
    • Dual projections of secondary vestibular axons in the medial longitudinal fasciculus to extraocular motor nuclei and the spinal cord of the squirrel monkey
    • Minor LB, McCrea RA, Goldberg JM. 1990. Dual projections of secondary vestibular axons in the medial longitudinal fasciculus to extraocular motor nuclei and the spinal cord of the squirrel monkey. Exp Brain Res 83:9-21.
    • (1990) Exp Brain Res , vol.83 , pp. 9-21
    • Minor, L.B.1    McCrea, R.A.2    Goldberg, J.M.3
  • 32
    • 0344212270 scopus 로고
    • The ontogenetic development of the oculomotor nucleus in the chick
    • Niimi K, Sakai T, Takasu J. 1958. The ontogenetic development of the oculomotor nucleus in the chick. Tokushima J Exp Med 5:311-325.
    • (1958) Tokushima J Exp Med , vol.5 , pp. 311-325
    • Niimi, K.1    Sakai, T.2    Takasu, J.3
  • 33
    • 0028483217 scopus 로고
    • A physiological and structural study of neuron types in the cochlear nucleus. II. Neuron types and their structural correlation with response properties
    • Ostapoff EM, Feng JJ, Morest DK. 1994. A physiological and structural study of neuron types in the cochlear nucleus. II. Neuron types and their structural correlation with response properties. J Comp Neurol 346:19-42.
    • (1994) J Comp Neurol , vol.346 , pp. 19-42
    • Ostapoff, E.M.1    Feng, J.J.2    Morest, D.K.3
  • 35
    • 0025122096 scopus 로고
    • Ultrastructural study of synapses at time of neuronal migration and early differentiation in the tangential vestibular nucleus of the chick embryo in vivo
    • Petralia RS, Peusner KD. 1990. Ultrastructural study of synapses at time of neuronal migration and early differentiation in the tangential vestibular nucleus of the chick embryo in vivo. J Comp Neurol 292:231-245.
    • (1990) J Comp Neurol , vol.292 , pp. 231-245
    • Petralia, R.S.1    Peusner, K.D.2
  • 36
    • 0026045329 scopus 로고
    • The earliest ultrastructural development of the tangential vestibular nucleus in the chick embryo
    • Petralia RS, Peusner KD. 1991. The earliest ultrastructural development of the tangential vestibular nucleus in the chick embryo. J Comp Neurol 310:82-93.
    • (1991) J Comp Neurol , vol.310 , pp. 82-93
    • Petralia, R.S.1    Peusner, K.D.2
  • 37
    • 0025282021 scopus 로고
    • Vestibulo-ocular projections in the 11-day chicken embryo: Pathway specificity
    • Pétursdóttir G. 1990. Vestibulo-ocular projections in the 11-day chicken embryo: pathway specificity. J Comp Neurol 297:283-297.
    • (1990) J Comp Neurol , vol.297 , pp. 283-297
    • Pétursdóttir, G.1
  • 38
    • 0030838909 scopus 로고    scopus 로고
    • Ontogeny of electrophysiological properties and dendritic pattern in second-order chick vestibular neurons
    • Peusner KD, Giaume C. 1997. Ontogeny of electrophysiological properties and dendritic pattern in second-order chick vestibular neurons. J Comp Neurol 384:621-633.
    • (1997) J Comp Neurol , vol.384 , pp. 621-633
    • Peusner, K.D.1    Giaume, C.2
  • 39
    • 0017754814 scopus 로고
    • The neuronal architecture and topography of the nucleus vestibularis tangentialis in the late chick embryo
    • Peusner KD, Morest DK. 1977a. The neuronal architecture and topography of the nucleus vestibularis tangentialis in the late chick embryo. Neuroscience 2:189-207.
    • (1977) Neuroscience , vol.2 , pp. 189-207
    • Peusner, K.D.1    Morest, D.K.2
  • 40
    • 0017647063 scopus 로고
    • A morphological study of neurogenesis in the nucleus vestibularis tangentialis of the chick embryo
    • Peusner KD, Morest DK. 1977b. A morphological study of neurogenesis in the nucleus vestibularis tangentialis of the chick embryo. Neuroscience 2:209-227.
    • (1977) Neuroscience , vol.2 , pp. 209-227
    • Peusner, K.D.1    Morest, D.K.2
  • 41
    • 33947598913 scopus 로고    scopus 로고
    • Otolith fibers and terminals in chick vestibular nuclei
    • Popratiloff A, Peusner KD. 2007. Otolith fibers and terminals in chick vestibular nuclei. J Comp Neurol 502:19-37.
    • (2007) J Comp Neurol , vol.502 , pp. 19-37
    • Popratiloff, A.1    Peusner, K.D.2
  • 43
    • 74049100046 scopus 로고    scopus 로고
    • Ramon y Cajal S. 1908. Les ganglions terminaux du nerf acousticque des oiseaux. Trab Lab Invest Biol Univ Madr 6:195-224.
    • Ramon y Cajal S. 1908. Les ganglions terminaux du nerf acousticque des oiseaux. Trab Lab Invest Biol Univ Madr 6:195-224.
  • 45
    • 84981841500 scopus 로고
    • A consideration of certain bulbar, midbrain and cerebellar centers and fiber tracts in birds
    • Sanders EB. 1929. A consideration of certain bulbar, midbrain and cerebellar centers and fiber tracts in birds. J Comp Neurol 49:155-222.
    • (1929) J Comp Neurol , vol.49 , pp. 155-222
    • Sanders, E.B.1
  • 46
    • 0034638267 scopus 로고    scopus 로고
    • The normal distribution and projections of constitutive NADPH-d/NOS neurons in the brainstem vestibular complex of the rat
    • Saxon DW, Beitz AJ. 2000. The normal distribution and projections of constitutive NADPH-d/NOS neurons in the brainstem vestibular complex of the rat. J Comp Neurol 425:97-120.
    • (2000) J Comp Neurol , vol.425 , pp. 97-120
    • Saxon, D.W.1    Beitz, A.J.2
  • 47
    • 33646176155 scopus 로고    scopus 로고
    • Physiological and anatomical properties of mouse medial vestibular nucleus neurons projecting to the oculomotor nucleus
    • Sekirnjak C, du Lac S. 2006. Physiological and anatomical properties of mouse medial vestibular nucleus neurons projecting to the oculomotor nucleus. J Neurophysiol 95:3012-3023.
    • (2006) J Neurophysiol , vol.95 , pp. 3012-3023
    • Sekirnjak, C.1    du Lac, S.2
  • 48
    • 0041315443 scopus 로고    scopus 로고
    • Spontaneous synaptic activity is primarily GABAergic in vestibular nucleus neurons of the chick embryo
    • Shao M, Hirsch JC, Giaume C, Peusner KD. 2003 Spontaneous synaptic activity is primarily GABAergic in vestibular nucleus neurons of the chick embryo. J Neurophysiol 90:1182-1192.
    • (2003) J Neurophysiol , vol.90 , pp. 1182-1192
    • Shao, M.1    Hirsch, J.C.2    Giaume, C.3    Peusner, K.D.4
  • 49
    • 3042550767 scopus 로고    scopus 로고
    • Spontaneous synaptic activity in chick vestibular nucleus neurons during the perinatal period
    • Shao M, Hirsch JC, Giaume C, Peusner KD. 2004. Spontaneous synaptic activity in chick vestibular nucleus neurons during the perinatal period. Neuroscience 127:81-90.
    • (2004) Neuroscience , vol.127 , pp. 81-90
    • Shao, M.1    Hirsch, J.C.2    Giaume, C.3    Peusner, K.D.4
  • 50
    • 33746001401 scopus 로고    scopus 로고
    • Maturation of firing pattern in chick vestibular nucleus neurons
    • Shao M, Hirsch JC, Peusner KD. 2006a. Maturation of firing pattern in chick vestibular nucleus neurons. Neuroscience 141:711-726.
    • (2006) Neuroscience , vol.141 , pp. 711-726
    • Shao, M.1    Hirsch, J.C.2    Peusner, K.D.3
  • 51
    • 33748543567 scopus 로고    scopus 로고
    • Emergence of action potential generation and synaptic transmission in vestibular nucleus neurons
    • Shao M, Hirsch JC, Peusner KD. 2006b. Emergence of action potential generation and synaptic transmission in vestibular nucleus neurons. J Neurophysiol 96:1215-1226.
    • (2006) J Neurophysiol , vol.96 , pp. 1215-1226
    • Shao, M.1    Hirsch, J.C.2    Peusner, K.D.3
  • 53
    • 0021019966 scopus 로고
    • Direct projections from vestibular nuclei to facial nucleus in cats
    • Shaw MD, Baker R. 1983. Direct projections from vestibular nuclei to facial nucleus in cats. J Neurophysiol 50:1265-1280.
    • (1983) J Neurophysiol , vol.50 , pp. 1265-1280
    • Shaw, M.D.1    Baker, R.2
  • 54
    • 27744481177 scopus 로고    scopus 로고
    • Intrinsic membrane properties of vertebrate vestibular neurons: Function, development and plasticity
    • Straka H, Vibert N, Vidal PP, Moore LE, Dutia MB. 2005. Intrinsic membrane properties of vertebrate vestibular neurons: function, development and plasticity. Prog Neurobiol 76:349-392.
    • (2005) Prog Neurobiol , vol.76 , pp. 349-392
    • Straka, H.1    Vibert, N.2    Vidal, P.P.3    Moore, L.E.4    Dutia, M.B.5
  • 55
    • 0003250106 scopus 로고
    • The upright head in hominid evolution
    • Berthoz A, Vidal PP, Graf W, editors, New York: Oxford University Press
    • Tobias PV. 1992. The upright head in hominid evolution. In: Berthoz A, Vidal PP, Graf W, editors. The head-neck sensory motor system. New York: Oxford University Press.
    • (1992) The head-neck sensory motor system
    • Tobias, P.V.1
  • 56
    • 0027971362 scopus 로고
    • Developmental relations between sixth nerve motor neurons and their targets in the chick embryo
    • Wahl CM, Noden DM, Baker R. 1994. Developmental relations between sixth nerve motor neurons and their targets in the chick embryo. Dev Dyn 201:191-202.
    • (1994) Dev Dyn , vol.201 , pp. 191-202
    • Wahl, C.M.1    Noden, D.M.2    Baker, R.3
  • 57
    • 0014036114 scopus 로고
    • The head movement of walking birds
    • 31P
    • Whiteside TCD. 1967. The head movement of walking birds. J Physiol 188:31P.
    • (1967) J Physiol , vol.188
    • Whiteside, T.C.D.1
  • 58
    • 0023885532 scopus 로고
    • Vestibular projections to the thalamus of the pigeon: An anatomical study
    • Wild JM. 1988. Vestibular projections to the thalamus of the pigeon: an anatomical study. J Comp Neurol 271:451-60.
    • (1988) J Comp Neurol , vol.271 , pp. 451-460
    • Wild, J.M.1
  • 59
    • 0018096768 scopus 로고
    • The vestibular nuclei in the domestic hen (Gallus domesticus): Ascending projections to the mesencephalic eye motor nuclei
    • Wold JE. 1978. The vestibular nuclei in the domestic hen (Gallus domesticus): ascending projections to the mesencephalic eye motor nuclei. J Comp Neurol 179:393-406.
    • (1978) J Comp Neurol , vol.179 , pp. 393-406
    • Wold, J.E.1
  • 60
    • 0034162647 scopus 로고    scopus 로고
    • Rapid compensatory changes in GABA receptor efficacy in rat vestibular neurones after unilateral labyrinthectomy
    • Yamanaka T, Him A, Cameron SA, Dutia MB. 2000. Rapid compensatory changes in GABA receptor efficacy in rat vestibular neurones after unilateral labyrinthectomy. J Physiol 523:413-424.
    • (2000) J Physiol , vol.523 , pp. 413-424
    • Yamanaka, T.1    Him, A.2    Cameron, S.A.3    Dutia, M.B.4
  • 61
    • 0035972109 scopus 로고    scopus 로고
    • Morphology and physiology of neurons in the ventral nucleus of the lateral lemniscus in rat brain slices
    • Zhao M, Wu SH. 2001. Morphology and physiology of neurons in the ventral nucleus of the lateral lemniscus in rat brain slices. J Comp Neurol 433:255-271.
    • (2001) J Comp Neurol , vol.433 , pp. 255-271
    • Zhao, M.1    Wu, S.H.2


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.