BRAIN and NERVE－神経研究の進歩62巻11号

2010年11月発行

増大特集 歩行とその異常

移動行動における脊髄反射の役割

著者： 小宮山伴与志¹

所属機関： ¹千葉大学教育学部保健体育教室

ページ範囲：P.1129 - P.1137

文献概要

はじめに

　歩行運動の神経制御に関しては，四足歩行動物の慢性および急性実験から，その理解が急速に進みつつある^1－6）。そして，四足歩行動物では，各肢と関節に歩行運動特有の筋活動パターンを作り出すパターン発振器（central pattern generator：CPG）が存在し，それらが大脳，小脳，中脳などからの下行性指令により駆動されることで歩行運動が生起し，調節されると考えられている^4－6）。求心性入力もCPGの調節に重要な役割を果たすと考えられる。

　一方，ヒトにおける二足歩行の制御に関しては，実験的な制約からその直接的な証拠を提示することは非常に困難である。しかし，脊髄反射を指標にした実験，新生児の原始歩行に関する実験，脊髄損傷患者における知見，脊髄硬膜外電気刺激実験などにより，CPGの存在が示唆されている^7－12）。特に，各種移動行動中のヒトにおける脊髄反射は，CPGの強い制御下にあることが明らかにされつつある^{8，12，13）}。これらの理解がさらに進めば，さまざまな原因で歩行障害を有する人たちへの理学療法やリハビリテーショントレーニングへの応用が展開してゆくものと考えられる^{7，12，14）}。本稿では，特にこれまでヒトを対象として明らかにされてきた，歩行運動時における脊髄反射の調節とその機能的な意義に焦点を当てて概説する。

参考文献

1) Bizzi E, Tresch MC, Saltiel P, d'Avella A: New perspectives on spinal motor systems. Nat Rev Neurosci 1: 101-108, 2000

2) Juvin L, Simmers J, Morin D: Locomotor rhythmogenesis in the isolated rat spinal cord: a phase-coupled set of symmetrical flexion extension oscillators. J Physiol 583: 115-128, 2007

3) Kiehn O: Locomotor circuits in the mammalian spinal cord. Annu Rev Neurosci 29: 279-306, 2006

4) McCrea DA, Rybak IA: Organization of mammalian locomotor rhythm and pattern generation. Brain Res Rev 57: 134-146, 2008

5) Orlovsky GN, Deliagina TG, Grillner S: Neural control of locomotion, Oxford University Press, New York, 1999

6) Rossignol S, Dubuc R, Gossard JP: Dynamic sensorimotor interactions in locomotion. Physiol Rev 86: 89-154, 2006

7) Calancie B, Needham-Shropshire B, Jacobs P, Willer K, Zych G, et al: Involuntary stepping after chronic spinal cord injury. Evidence for a central rhythm generator for locomotion in man. Brain 117: 1143-1159, 1994

8) Dietz V: Do human bipeds use quadrupedal coordination? Trends Neurosci 25: 462-467, 2002

9) Dimitrijevic MR, Gerasimenko Y, Pinter MM: Evidence for a spinal central pattern generator in humans. Ann N Y Acad Sci 860: 360-376, 1998

10) Sasada S, Tazoe T, Nakajima T, Zehr EP, Komiyama T: Effects of leg pedaling on early latency cutaneous reflexes in upper limb muscles. J Neurophysiol 104: 210-217, 2010

11) Yang JF, Gorassini M: Spinal and brain control of human walking: implications for retraining of walking. Neuroscientist 12: 379-389, 2006

12) Zehr EP, Duysens J: Regulation of arm and leg movement during human locomotion. Neuroscientist 10: 347-361, 2004

13) Zehr EP, Collins DF, Chua R: Human interlimb reflexes evoked by electrical stimulation of cutaneous nerves innervating the hand and foot. Exp Brain Res 140: 495-504, 2001

14) Dietz V, Harkema SJ: Locomotor activity in spinal cord-injured persons. J Appl Physiol 96: 1954-1960, 2004

15) Dietz V, Quintern J, Sillem M: Stumbling reactions in man: significance of proprioceptive and pre-programmed mechanisms. J Physiol 368: 149-163, 1987

16) Yang JF, Stein RB, James KB: Contribution of peripheral afferents to the activation of the soleus muscle during walking in humans. Exp Brain Res 87: 679-687, 1991

17) Sinkjaer T, Andersen JB, Ladouceur M, Christensen LO, Nielsen JB: Major role for sensory feedback in soleus EMG activity in the stance phase of walking in man. J Physiol 523: 817-827, 2000

18) Cronin NJ, Ishikawa M, Grey MJ, af Klint R, Komi PV, et al: Mechanical and neural stretch responses of the human soleus muscle at different walking speeds. J Physiol 587: 3375-3382, 2009

19) Grey MJ, Nielsen JB, Mazzaro N, Sinkjaer T: Positive force feedback in human walking. J Physiol 581: 99-105, 2007

20) Stein RB, Capaday C: The modulation of human reflexes during functional motor tasks. Trends Neurosci 11: 328-332, 1988

21) Stein RB: Presynaptic inhibition in humans. Prog Neurobiol 47: 533-544, 1995

22) Capaday C, Stein RB: Amplitude modulation of the soleus H-reflex in the human during walking and standing. J Neurosci 6: 1308-1313, 1986

23) Edamura M, Yang JF, Stein RB: Factors that determine the magnitude and time course of human H-reflexes in locomotion. J Neurosci 11: 420-427, 1991

24) Prochazka A, Hulliger M, Trend P, Durmuller N: Dynamic and static fusimotor set in various behavioural contexts. In: Mechanoreceptors: development, structure, and function. (Edited by P. Hnik P et al), Plenum Press, New York, pp417-430, 1988

25) Simonsen EB, Dyhre-Poulsen P: Amplitude of the human soleus H reflex during walking and running. J Physiol 515: 929-939, 1999

26) Simonsen EB, Dyhre-Poulsen P, Alkjaer T, Aagaard P, et al: Interindividual differences in H reflex modulation during normal walking. Experimental Brain Research 142: 108-115, 2002

27) Courtine G, Harkema SJ, Dy CJ, Gerasimenko YP, Dyhre-Poulsen P: Modulation of multisegmental monosynaptic responses in a variety of leg muscles during walking and running in humans. J Physiol 582: 1125-1139, 2007

28) Brooke JD, Cheng J, Collins DF, McIlroy WE, Misiaszek JE et al: Sensori-sensory afferent conditioning with leg movement: gain control in spinal reflex and ascending paths. Prog Neurobiol 51: 393-421, 1997

29) Misiaszek JE, Pearson KG: Stretch of quadriceps inhibits the soleus H reflex during locomotion in decerebrate cats. J Neurophysiol 78: 2975-2984, 1997

30) Capaday C, Cody FW, Stein RB: Reciprocal inhibition of soleus motor output in humans during walking and voluntary tonic activity. J Neurophysiol 64: 607-616, 1990

31) Lavoie BA, Devanne H, Capaday C: Differential control of reciprocal inhibition during walking versus postural and voluntary motor tasks in humans. J Neurophysiol 78: 429-438, 1997

32) Schneider C, Lavoie BA, Capaday C: On the origin of the slues H-reflex modulation pattern during human walking and its task-dependent differences. J Neurophysiol 83: 2881-2890, 2000

33) Petersen N, Morita H, Nielsen J: Modulation of reciprocal inhibition between ankle extensors and flexors during walking in man. J Physiol 520: 605-619, 1999

34) Lamy JC, Iglesias C, Lackmy A, Nielsen JB, Katz R, et al: Modulation of recurrent inhibition from knee extensors to ankle motoneurones during human walking. J Physiol 586: 5931-5946, 2008

35) Hodapp M, Klisch C, Berger W, Mall V, Faist M: Modulation of soleus H-reflexes during gait in healthy children. Exp Brain Res 178: 252-260, 2007

36) Hodapp M, Vry J, Mall V, Faist M: Changes in soleus H-reflex modulation after treadmill training in children with cerebral palsy. Brain 132: 37-44, 2009

37) Christensen LO, Petersen N, Andersen JB, Sinkjaer T, Nielsen JB: Evidence for transcortical reflex pathways in the lower limb of man. Prog Neurobiol 62: 251-272, 2000

38) Komiyama T, Zehr EP, Stein RB: Absence of nerve specificity in human cutaneous reflexes during standing. Exp Brain Res 133: 267-272, 2000

39) Zehr EP, Stein RB, Komiyama T: Function of sural nerve reflexes during human walking. J Physiol 507: 305-314, 1998

40) Zehr EP, Stein RB: What functions do reflexes serve during human locomotion?. Prog Neurobiol 58: 185-205, 1999

41) Zehr EP, Komiyama T, Stein RB: Cutaneous reflexes during human gait: electrical and kinematic responses to electrical stimulation. J Neurophysiol 77: 3311-3325, 1997

42) Haridas C, Zehr EP: Coordinated interlimb compensatory responses to electrical stimulation of cutaneous nerves in the hand and foot during walking. J Neurophysiol 90: 2850-2861, 2003

43) Zehr EP, Hundza SR, Vasudevan EV: The quadrupedal nature of human bipedal locomotion. Exerc Sport Sci Rev 37: 102-108, 2009

44) Sakamoto M, Endoh T, Nakajima T, Tazoe T, Shiozawa S, et al: Modulations of interlimb and intralimb cutaneous reflexes during simultaneous arm and leg cycling in humans. Clin Neurophysiol 117: 1301-1311, 2006

45) Zehr EP: Neural control of rhythmic human movement: the common core hypothesis. Exerc Sport Sci Rev 33: 54-60, 2005

46) Zehr EP, Balter JE, Ferris DP, Hundza SR, et al: Neural regulation of rhythmic arm and leg movement is conserved across human locomotor tasks. J Physiol 582: 209-227, 2007