Faculty of Biological Sciences

Dr Ronaldo Ichiyama

Ph.D 2002, M.Sc. 1998
Associate Professor in Motor Control
School of Biomedical Sciences

Background: B.Sc., Lic. Universidade Estadual de Campinas (Brazil), M.Sc. University of Illinois at Urbana-Champaign (USA), Ph.D. University of Illinois at Urbana-Champaign (USA), Postdoctoral Fellow University of California Los Angeles (USA)

Contact:  Garstang G5.55a, +44(0) 113 34 34291, email address for  

Research Interests

Structural and Functional Plasticity in the CNS : activity dependent plasticity in the spinal cord

Neural Control of Movement

The mechanisms related to the neural control of movement in mammalian systems are largely unanswered, simply because the intricacies of interneuronal communication and computations necessary to produce coordinated, voluntary movements are of such complexity that we have only begun to understand them. Relative to the overwhelming complexity of the supraspinal control of movement, the spinal neural circuits provide a simpler model to investigate motor control issues. This does not, however, imply that spinal control of movement in mammalian species is a simple model. My research has focused on the changes within the spinal cord that occur after a complete spinal cord transection and on the activity-dependent plasticity in the spinal neural circuits associated with locomotor training after the spinal cord injury. We have used behavioural, immunohistochemical, electron microscopic and electrophysiologic methods to investigate those issues. The combined results strongly suggest that the biochemical, structural, and electrophysiological properties of motoneurons change dramatically within the spinal cord isolated from the brain, which are altered by locomotor training. Understanding these processes in detail will provide critical insight into the mechanisms involved in the control and learning of movements within spinal cord neural circuits.

explained in caption

A,B. Detailed kinematics analysis of movement and physiological measurements such as EMG (C) are combined to study the neuronal events that lead to plasticity in the CNS. D, shows selective spinal motoneurons (green) active during locomotion (red).

Neural Control of Cardiorespiratory Function in Exercise

Another interest in my lab is the neural control of cardiovascular function related to movement production and exercise. During muscular activity, two basic mechanisms control cardiovascular adjustments: a central command and a reflex arising from the contracting muscles, which is dependent on medullary centers. I have investigated issues related to both of those mechanisms. We have implicated higher cortical centers (insular cortex) in the central command circuitry.  In addition, I have demonstrated that specific locomotor and cardiovascular control areas in the brain change with exercise training.  The posterior hypothalamus nucleus, the mesencephalic locomotor region, periaqueductal grey, nucleus of the tractus solitarius and the rostral ventrolateral medulla showed diminished, possibly more efficient, activation profiles (cfos) in exercised than in non-exercised rats in response to a single bout of controlled exercise.

Spinal Cord Injury, Neural Regeneration and Functional Recovery

After a spinal cord injury, the remaining unaffected spinal tissue changes to a great extent. A successful neural regenerative strategy will have to overcome not only all the obstacles that the injury site itself presents (glial scaring, physical gap, etc.) but also a new environment that has formed below the level of the lesion. We hypothesize that the beneficial effects of locomotor training will potentiate the effects of regenerative strategies. We have combined locomotor training with different potential neural regenerative strategies, with both positive and surprising results. Given the nature of spinal cord injuries, we firmly believe that only a combination strategy will be effective in regenerating and forming functional synaptic reconnections after an injury.

We have developed a technique to epidurally stimulate the spinal cord, which produces alternating and coordinated steps in completely spinalized adult rats.  This technique allows us to study the control of locomotion in an in vivo adult mammalian preparation, which was not possible previously. We have used this technique to investigate reflex control mechanisms in the intact spinal cord and also after a complete spinal transection.

 

Current Projects

  • Locomotor Training in Chronic Adult Spinal Cord Injured Rats: Plasticity of interneurons and motoneurons.
  • Combinatorial interventions for recovery of function after spinal cord injuries: mechanisms of anti-Nogo-A antibody, epidural stimulation and locomotor training
  • Perineuronal nets and chondroitin sulfate proteoglycans in rehabilitation after spinal cord injuries.
  • Ultrastructural, physiological and functional plasticity of Gamma Motoneurons
  • Morphological and neurochemical characterization of central cardiorespiratory centers in exercise
  • Neuroregeneration and axonal sprouting: exercise and locomotor training

 

 

Faculty Research and Innovation



Studentship information

Postgraduate studentship areas:

  • Morphological and ultrastructural synaptic plasticity
  • Neural Regeneration and Exercise
  • Spinal Cord Injuries: locomotion and neural control of movement
  • Central control of cardiovascular and respiratory function in exercise

See also:

Modules managed

SPSC3125 - Motor Control and Neurorehabilitation
SPSC5382 - Extended Research Project

Modules taught

BMSC3126/43/44/45/46 A - ATU - Integrative biomedical sciences
SPSC2240 - Human Motor Development
SPSC2309 - Skill Acquisition, Motor Learning and Rehabilitation
SPSC2309/2131 - Skill Acq and Motor Learning
SPSC3061 - Research Project in Sport and Exercise Science II
SPSC3125 - Motor Control and Neurorehabilitation
SPSC3389 - Research Project

Academic roles

PGR Progression Tutor - School of Biomedical Sciences

Committees

Member of Graduate School Committee (Progression Tutor (SBMS))

Centre membership: Neuroscience Research at Leeds (NeuR@L)

Dr Varinder Lall  (Research Fellow)

Postgraduates

Richard Dickson (Primary supervisor) 90% FTE
Natalie Doody (Primary supervisor) 34% FTE
Roxanne Dyer (Primary supervisor) 60% FTE
Sian Irvine (Co-supervisor) 10% FTE
Trang Nguyen (Co-supervisor) 20% FTE
William Shaw (Co-supervisor) 10% FTE
Nicole Smith (Co-supervisor) 33% FTE
Katherine Timms (Co-supervisor) 12% FTE

Smith CC, Paton JFR, Chakrabarty S, Ichiyama RM Descending systems direct development of key spinal motor circuits Journal of Neuroscience 37 6372-6387, 2017
DOI:10.1523/JNEUROSCI.0149-17.2017
View abstract

Chen K, Marsh BC, Cowan M, Al'Joboori YD, Gigout S, Smith CC, Messenger N, Gamper N, Schwab ME, Ichiyama RM Sequential therapy of anti-Nogo-A antibody treatment and treadmill training leads to cumulative improvements after spinal cord injury in rats Experimental Neurology 292 135-144, 2017
DOI:10.1016/j.expneurol.2017.03.012
View abstract

Britten L, Coats R, Ichiyama R, Raza W, Jamil F, Astill S Bimanual reach to grasp movements after cervical spinal cord injury PLoS ONE 12 -, 2017
DOI:10.1371/journal.pone.0175457
View abstract

Cowan M, Ichiyama RM Mechanisms of Functional Recovery with Exercise and Rehabilitation in Spinal Cord Injuries In Physical Activity and the Aging Brain Effects of Exercise on Neurological Function , 2017
View abstract

Smith CC, Mauricio R, Nobre L, Marsh B, Wüst RCI, Rossiter HB, Ichiyama RM Differential regulation of perineuronal nets in the brain and spinal cord with exercise training Brain Research Bulletin 111 20-26, 2015
DOI:10.1016/j.brainresbull.2014.12.005
View abstract

Abud EM, Ichiyama RM, Havton LA, Chang HH Spinal stimulation of the upper lumbar spinal cord modulates urethral sphincter activity in rats after spinal cord injury American Journal of Physiology - Renal Physiology 308 F1032-F1040, 2015
DOI:10.1152/ajprenal.00573.2014
View abstract

Murphy MN, Ichiyama RM, Iwamoto GA, Mitchell JH, Smith SA Exercise pressor reflex function following acute hemi-section of the spinal cord in cats. Front Physiol 4 -, 2013
DOI:10.3389/fphys.2013.00003
View abstract

Wang D, Ichiyama RM, Zhao R, Andrews MR, Fawcett JW Chondroitinase combined with rehabilitation promotes recovery of forelimb function in rats with chronic spinal cord injury. J Neurosci 31 9332-9344, 2011
DOI:10.1523/JNEUROSCI.0983-11.2011
View abstract

Marsh BC, Astill SL, Utley A, Ichiyama RM Movement rehabilitation after spinal cord injuries: Emerging concepts and future directions BRAIN RES BULL 84 327-336, 2011
DOI:10.1016/j.brainresbull.2010.07.011

Ichiyama RM, Broman J, Roy RR, Zhong H, Edgerton VR, Havton LA Locomotor Training Maintains Normal Inhibitory Influence on Both Alpha- and Gamma-Motoneurons after Neonatal Spinal Cord Transection J NEUROSCI 31 26-33, 2011
DOI:10.1523/JNEUROSCI.6433-09.2011

Hilaire G, Voituron N, Menuet C, Ichiyama RM, Subramanian HH, Dutschmann M The role of serotonin in respiratory function and dysfunction RESP PHYSIOL NEUROBI 174 76-88, 2010
DOI:10.1016/j.resp.2010.08.017

Courtine G, Gerasimenko Y, van den Brand R, Yew A, Musienko P, Zhong H, Song BB, Ao Y, Ichiyama RM, Lavrov I, Roy RR, Sofroniew MV, Edgerton VR Transformation of nonfunctional spinal circuits into functional states after the loss of brain input NAT NEUROSCI 12 1333-U167, 2009
DOI:10.1038/nn.2401

Ichiyama R, Potuzak M, Balak M, Kalderon N, Edgerton VR Enhanced Motor Function by Training in Spinal Cord Contused Rats Following Radiation Therapy PLOS ONE 4 -, 2009
DOI:10.1371/journal.pone.0006862

Maier IC, Ichiyama RM, Courtine G, Schnell L, Lavrov I, Edgerton VR, Schwab ME Differential effects of anti-Nogo-A antibody treatment and treadmill training in rats with incomplete spinal cord injury BRAIN 132 1426-1440, 2009
DOI:10.1093/brain/awp085

Fong AJ, Roy RR, Ichiyama RM, Lavrov I, Courtine G, Gerasimenko Y, Tai YC, Burdick J, Edgerton VR Recovery of control of posture and locomotion after a spinal cord injury: solutions staring us in the face. Prog Brain Res 175 393-418, 2009
DOI:10.1016/S0079-6123(09)17526-X
View abstract

Ichiyama RM, Courtine G, Gerasimenko YP, Yang GJ, van den Brand R, Lavrov IA, Zhong H, Roy RR, Edgerton VR Step training reinforces specific spinal locomotor circuitry in adult spinal rats J NEUROSCI 28 7370-7375, 2008
DOI:10.1523/JNEUROSCI.1881-08.2008

Ichiyama RM, Gerasimenko Y, Jindrich DL, Zhong H, Roy RR, Edgerton VR Dose dependence of the 5-HT agonist quipazine in facilitating spinal stepping in the rat with epidural stimulation. Neurosci Lett 438 281-285, 2008
DOI:10.1016/j.neulet.2008.04.080
View abstract

Edgerton VR, Courtine G, Gerasimenko YP, Lavrov I, Ichiyama RM, Fong AJ, Cai LL, Otoshi CK, Tillakaratne NJK, Burdick JW, Roy RR Training locomotor networks. Brain Res Rev 57 241-254, 2008
DOI:10.1016/j.brainresrev.2007.09.002
View abstract

Gerasimenko YP, Ichiyama RM, Lavrov IA, Courtine G, Cai L, Zhong H, Roy RR, Edgerton VR Epidural spinal cord stimulation plus quipazine administration enable stepping in complete spinal adult rats. J Neurophysiol 98 2525-2536, 2007
DOI:10.1152/jn.00836.2007
View abstract

Petruska JC, Ichiyama R, Jindrich DL, Crown ED, Tansey KE, Roy RR, Edgerton V, Mendell LM Changes in Motoneuron Properties and Synaptic Inputs Related to Step Training Following Spinal Cord Transection in Rats Journal of Neuroscience 27 4460-4471, 2007
DOI:10.1523/JNEUROSCI.2302-06.2007

Engesser-Cesar C, Ichiyama RM, Nefas AL, Hill MA, Edgerton VR, Cotman CW, Anderson AJ Wheel running following spinal cord injury improves locomotor recovery and stimulates serotonergic fiber growth. Eur J Neurosci 25 1931-1939, 2007
DOI:10.1111/j.1460-9568.2007.05469.x
View abstract

Ichiyama R, Broman J, Edgerton V, Havton LA Ultrastructural synaptic features differ betweenα- andγ-motoneurons innervating the tibialis anterior muscle in the rat. Journal of Comparative Neurology 499 306-315, 2006
DOI:10.1002/cne.21110

Gerasimenko YP, Lavrov IA, Courtine G, Ichiyama RM, Dy CJ, Zhong H, Roy RR, Edgerton VR Spinal cord reflexes induced by epidural spinal cord stimulation in normal awake rats. J Neurosci Methods 157 253-263, 2006
DOI:10.1016/j.jneumeth.2006.05.004
View abstract

Lavrov I, Gerasimenko YP, Ichiyama RM, Courtine G, Zhong H, Roy RR, Edgerton VR Plasticity of spinal cord reflexes after a complete transection in adult rats: relationship to stepping ability. J Neurophysiol 96 1699-1710, 2006
DOI:10.1152/jn.00325.2006
View abstract

Ichiyama RM Supraspinal locomotor centers do/do not contribute significantly to the hyperpnea of dynamic exercise in humans. J Appl Physiol (1985) 100 1745-, 2006

Eldridge FL, Morin D, Romaniuk JR, Yamashiro S, Potts JT, Ichiyama RM, Bell H, Phillipson EA, Killian KJ, Jones NL, Nattie E Supraspinal locomotor centers do/do not contribute significantly to the hyperpnea of dynamic exercise in humans. J Appl Physiol (1985) 100 1743-1747, 2006
DOI:10.1152/japplphysiol.00117.2006

Edgerton VR, Kim SJ, Ichiyama RM, Gerasimenko YP, Roy RR Rehabilitative therapies after spinal cord injury. J Neurotrauma 23 560-570, 2006
DOI:10.1089/neu.2006.23.560
View abstract

Ichiyama R, Gerasimenko Y, Zhong H, Roy RR, Edgerton V Hindlimb stepping movements in complete spinal rats induced by epidural spinal cord stimulation Neuroscience Letters 383 339-344, 2005
DOI:10.1016/j.neulet.2005.04.049

Ichiyama RM, Waldrop TG, Iwamoto GA Neurons in and near insular cortex are responsive to muscular contraction and have sympathetic and/or cardiac-related discharge. Brain Res 1008 273-277, 2004
DOI:10.1016/j.brainres.2004.02.034
View abstract

Nelson AJ, Ragan BG, Bell GW, Ichiyama RM, Iwamoto GA Capsaicin-based analgesic balm decreases pressor responses evoked by muscle afferents. Med Sci Sports Exerc 36 444-450, 2004
View abstract

Ichiyama RM, Ragan BG, Bell GW, Iwamoto GA Effects of topical analgesics on the pressor response evoked by muscle afferents. Med Sci Sports Exerc 34 1440-1445, 2002
DOI:10.1249/01.MSS.0000027760.27844.45
View abstract

Ichiyama R, Gilbert AB, Waldrop TG, Iwamoto GA Changes in the exercise activation of diencephalic and brainstem cardiorespiratory areas after training. Brain Research 947 225-233, 2002
DOI:10.1016/S0006-8993(02)02929-3

Carlton LG, Chow JW, Ekkekakis P, Shim J, Ichiyama R, Carlton MJ A Web-based digitized video image system for the study of motor coordination. Behav Res Methods Instrum Comput 31 57-62, 1999
View abstract

Ichiyama R, Roy RR, Edgerton VR Assessment of sensorimotor function after spinal cord injury and repair In Texbook of Neural Repair and Rehabilitation ,