donld_dunbarDr. Donald C. Dunbar

Professor Med Sci Campus Main Bldg, Lab A514/A515/A516
donald.dunbar@upr.edu
787-758-2525 x1509

Interests: Mammalian functional morphology and biomechanics, and neural control of locomotion and posture.

My laboratory investigates questions concerning movement and the underlying neural, biomechanical, and morphological mechanisms. I am interested primarily in natural and volitional movements, as opposed to artificial or unnatural movements often required of laboratory protocols that place unnatural constraints on subjects. I work with humans and animals, the species chosen being dependent upon the questions asked.

The majority of my work has been in locomotion and posture in humans, monkeys, horses, cats, and rats, which has been conducted in the laboratory (Puerto Rico, Illinois, Oregon, California, Canada, France) and field (India, Caribbean Primate Research Center). In recent years, I have focused on how head, neck, and trunk movements are coordinated, and how these coordination patterns relate to the nervous system′s requirements for the perception and control of whole-body spatial orientation and navigation. My most recent interests have expanded into spinal cord injury and recovery through a research sabbatical at the University of California, Los Angeles during the 2006-2007 Academic Year. The research project that is currently being conducted with UCLA concerns the ability of monkeys (as a biomedical animal model) to reach, grasp, and retrieve a food reward before and after a surgical lesion (hemisection) of the spinal cord at C6-C7. We are charting the behavioral, biomechanical, and neural changes that occur over a 6-month post-lesion period. Some of the monkeys have one or more surgical and chemical interventions at the time of surgery in an attempt to induce re-growth of damaged spinal cord neurons and/or cross-sprouting of contralaterally spared neurons. A second spinal cord injury investigation, also in collaboration with UCLA, is in the formative stages and is planned to begin in late January or early February. We will be conducting a pilot study at the Sabana Seca facility of the Caribbean Primate Research Center that will place stimulating electrodes on the dura mater in the lumbosacral region of spinally hemisected (~T-10 level) monkeys. The purpose of the study is to enable these monkeys to walk symmetrically again post-lesion by continuously stimulating the central pattern generator (CPG) for the lower limbs, which is located in the upper lumbar region of the spinal cord.

The techniques used for data collection in my studies include video and motion picture recording of natural behaviors, computer-based kinematic (movement) and/or kinetic (force) analysis, electromyography (recording of muscle electrical activity), and morphometrics (anatomical measurement) and dissectional analyses of the associated anatomical structures.

Selected Publications:

  • D. C. Dunbar. (submitted September 2014) Jumping. In: A. Fuentes (ed.), International Encyclopedia of Primatology. Wiley-Blackwell, Hoboken, NJ.
  • Dunbar, D.C. (ed.). (2013) Primatology in the Neurosciences II. Virtual issue of Am J Primatol.
  • Dunbar, D.C. (2012) Physical anthropology at the Caribbean Primate Research Center: past, present, and future. In: Wang, Q. (ed.), Bones, Genetics, and Behavior of Rhesus Macaques: Cayo Santiago and Beyond. Springer, New York,
  • Dunbar DC, Macpherson JM, Simmons RW, Zarcades A. (2008) Stabilization and mobility of the head, neck and trunk in horses during overground locomotion: comparisons with humans and other primates. J Exp Biol. 211(Pt 24):3889-907.
  • Crespo MJ, J Zalacaín, N Cruz, DC Dunbar, L Arocho. (2008) Cardiac oxidative stress is elevated at the onset of dilated cardiomyopathy in STZ-diabetic Rats. J Cardiovasc Pharmacol Ther 13:64-71
  • Crespo MJ, J Quidgley, DC Dunbar. (2006) Differential regulation of left and right coronary arteries in swine. Pharmacol 77:137-43.
  • Dunbar DC. (2004) Stabilization and mobility of the head and trunk in vervet monkeys (Cercopithecus aethiops) during treadmill walks and gallops. J Exp Biol, 207:4427- 4438.
  • Dunbar DC, GL Badam, B Hallgrímsson, S Vieilledent. (2004) Stabilization and mobility of the head and trunk in wild primates during terrestrial and flat-surface walks and gallops. J Exp Biol, 207:1027-1042.
  • Crespo MJ, DC Dunbar. (2003) Enalapril improves vascular and cardiac function in Streptozotocin-diabetic rats. Cell Mol Biol, 49:1311-1318.
  • Dunbar DC, GL Badam. (2000) Locomotion and posture during terminal branch feeding. Int J Primatol, 21:649-669.
  • Dunbar DC, GL Badam. (1998) Development of posture and locomotion in free-ranging primates. Neurosci Biobehav Rev, 22:541-546.
  • Dunbar DC. (1994) The influence of segmental movements and design on wholebody rotations during the airborne phase of primate leaps. Z Morphol Anthropol, 80:109124.
  • Dunbar DC, JM Macpherson. (1993) Activity of compartments in lateral gastrocnemius evoked by postural corrections during stance. J Neurophysiol, 70:23372349.
  • Macpherson JM, FB Horak, DC Dunbar. (1989) Stance dependence of automatic postural adjustments in humans. Exp Brain Res, 78:557566.
  • Dunbar DC (1989) Locomotor behavior of rhesus macaques (Macaca mulatta) on Cayo Santiago. Puerto Rico Health Sci J, 8:7985.
  • Dunbar DC (1988) Aerial maneuvers of leaping lemurs: The physics of wholebody rotations while airborne. Am J Primatol, 16:291303.
  • Rushmer DS, DC Dunbar, CJ Russell, SL Windus. (1987) Automatic postural responses in the cat: Responses of distal hindlimb muscles to paired vertical perturbations of stance. Exp Brain Res, 68:477490.
  • Rushmer DS, JM Macpherson, DC Dunbar, CJ Russell, SL Windus. (1987) Automatic postural responses in the cat: Responses of proximal and distal hindlimb muscles to drop of support from a single hind or forelimb. Exp Brain Res, 65:527537.
  • Lukacs JR, RK Bogorad, SR Walimbe, DC Dunbar. (1986) Paleopathology at Inamgaon: A postHarappan agrarian village in western India. Proc Am Philos Soc, 130:289311.
  • Macpherson JM, DS Rushmer, DC Dunbar. (1986) Postural responses in the cat to unexpected rotations of the support surface: Evidence for a centrally generated synergic organization. Exp Brain Res, 62:152160.

  • Dunbar DC, F Horak, JM Macpherson, DS Rushmer. (1986) Neural control of quadrupedal and bipedal stance: Implications for the evolution of erect posture. Am J Phys Anthropol, 69:93105. Rushmer DS, CJ Russell, J Macpherson, JO Phillips, DC Dunbar. 1983 Automatic postural responses in the cat: Responses to headward and tailward translation. Exp Brain Res, 50:4561.

Selected abstracts/presentations:

  • Dunbar DC, D Jindrich, N Hamouda, R Roy, H Zhong, G Courtine, J Liu, T Bernot, R Moseanko, M Tuszynski, V Edgerton (2007) Manual prehension strategies in rhesus monkeys before and after cervical hemisection. Society for Neuroscience 37th Annual Meeting (San Diego, CA, 3-7 November 2007).
  • Dunbar DC, RW Simmons, A Zarcades (2005) Head, neck, and trunk stabilization in horses. International Society for Postural and Gait Research, 17th Conference (Marseilles, France, 29 May-2 June 2005). Gait and Posture, 21 (Suppl.1):S35.
  • Dunbar DC, RW Simmons, A Zarcades. (2004) Segmental stabilization in horses. Society for Neuroscience 34th Annual Meeting (San Diego, CA, 23-27 October 2004). Program No. 415.1, Abstract Viewer/Itinerary Planner. Washington, DC: Society for Neuroscience.
  • Sugrañes de la Vega M, DC Dunbar. (2004) Head movement and orientation during walks by Cayo Santiago rhesus macaques. Puerto Rico Health Sciences Journal, 23(2): 141(Abstract R-19).
  • Vieilledent S, Dunbar DC, Kerlirzin Y, Hallgrímsson B, Berthoz A. (2002) Multiple jumps: Heading toward a final target or multiple intermediate targets? Int Congr Movement, Attention & Perception (Potiers, France, 19-21 June)
  • Sugrañes de la Vega M, DC Dunbar (2002) Role of the ventral tubercle of the 6th cervical vertebra in rhesus monkeys for neck stabilization and mobility. Biomedical Research Forum, University of Puerto Rico Medical Sciences Campus, 19-19 April 2002
  • Dunbar DC, S Vieilledent, Y Kerlirzin, B Hallgrímsson, A Berthoz. (2001) Dissociation of distance and direction during locomotor trajectory formation by humans performing sequential jumps. Soc Neurosci Abstr, 27. (San Diego, CA, 10-15 November 2001)
  • Vieilledent S, D Dunbar, Y Kerlirzin, A Berthoz. (2000) Role de la vision dans les strategies motrices de changement de direction lors de sauts multiples. (Role of vision in motor strategies for change in direction during multiple jumps.) Actes des Journées d’Analyse du Mouvement-Utilizateurs Vicon (Proceedings of Vicon Motion Analysis System Users Day). Berck sur Mer, France, 24 March 2000.
  • Dunbar DC. (1999) Pathway choice by free-ranging primates. Gait & Posture, 9:S7.
  • Dunbar DC. (1998) Head and trunk stabilization in monkeys during treadmill locomotion. Neural Control of Movement Society Annual Meeting. Key West, FL, 14-19 April 1998.
  • Dunbar DC. (1998) Head and trunk stabilization and spatial orientation in primates. University of Puerto Rico Medical Sciences Campus 19th Annual Research and Education Forum Abstr, 19:59-60.
  • Dunbar DC. (1997) To move or not to move: Roles of body segment mobility and stability in natural posture and locomotion of primates. International Society for Postural and Gait Research, 13th International Symposium. Paris, France, 22-26 June 1997.
  • Dunbar DC. (1997) Head and trunk stabilization in different gaits of primates moving freely in natural habitats. Satellite Conference to Annual Neural Control of Movement Society Meeting: Sensory and Biomechanical Contributions to Posture. Cozumel, Mexico, 13-16 April 1997.
  • López W, J Artecona, S Morales, C Mejias, DC Dunbar, B Hallgrímsson, AC Segarra (1997) Maternal restraint stress and locomotor performance in rats. FASEB J Abstr, 11:A635.
  • Dunbar DC (1996) Development of natural posture and locomotion in free-ranging primates. European Brain and Behaviour Society Workshop: Development of Postural Control. Groningen, The Netherlands, 6-8 June 1996.
  • Dunbar DC, GL Badam. (1995) Head and trunk stabilization in natural gaits of freeranging monkeys. Soc Neurosci Abstr, 21:418.
  • La Puerta Resto M, DC Dunbar. (1995) Normal gait patterns of Puerto Rican adults. University of Puerto Rico Medical Sciences Campus 16th Annual Research Forum Abstracts, 16:74.
  • Dunbar DC, GL Badam. (1994) Locomotor mechanics of terminal branch feeding. J Morphol, 220:343.
  • Dunbar DC, GL Badam (1993) Quantitative aspects of terrestrial gaits in adult bonnet macaques and hanuman langurs. Am Zool, 33:74A.
  • Dunbar DC, GL Badam. (1992) Terrestrial gaits of wild bonnet macaques and hanuman langurs. Am Zool, 32:141.
  • Dunbar DC. (1992) How body segments influence wholebody rotations during the airborne phase of leaps. Abstr XIV Ann Cong Int Primatol Soc, 14:178.
  • Dunbar DC. (1991) How rhesus monkeys on Cayo Santiago initiate and change gait. University of Puerto Rico Medical Sciences Campus 13th Annual Research Forum Abstracts, 13:58.
  • Dunbar DC. (1990) Gait initiation and transitions by free-ranging rhesus monkeys (Macaca mulatta) on Cayo Santiago. Am J Phys Anthropol, 81:217218.
  • Dunbar DC, RG Rawlins. (1989) Arboreal locomotor behavior of juvenile rhesus macaques on Cayo Santiago. Am J Phys Anthropol, 78:215.
  • Dunbar DC, JM Macpherson, JT Inglis. (1988) Activity of lateral gastrocnemius compartments in the cat during postural corrections in the horizontal plane. Soc Neurosci Abstr, 14:63.
  • Dunbar DC. (1988) Postural control mechanisms in humans and quadrupeds. Am J Phys Anthropol, 75:206.
  • Dunbar DC. (1987) Postnatal development of hindlimb movements during swimming in rats. Anat Rec, 218:37A.