My research integrates biomechanics and neurobiology to study how axial movements are generated and coordinated to respond to the physical properties of an organism's environment. Of particular interest to me are the startle response and rhythmic swimming behaviors of fishes. These behaviors provide excellent model systems for examining motor control and the mechanics of axial movement. Because the startle response involves a discrete behavior, large neurons and simple neural circuits, it has been important in studies of motor control. Because it is critical for survival and involves maximal performance, it has been important for work on muscle physiology and performance. Rhythmic axial and fin swimming has long been studied in lampreys and tadpoles to examine central pattern generation in spinal circuits and in a wide diversity fishes to understand the relationship between morphology and movement.
The scope of questions I am asking can be divided into three interconnected research initiatives. The first explores the broad question: How do morphology, physiology and the physics of the aquatic environment interact to produce swimming movement? To address this question, I examine the scaling of locomotor performance through development with changes in the physics of movement such as the Reynolds number, a ratio of inertial to viscous forces. The second area examines the generation of swimming movements. Questions I am addressing include: How do reticulospinal and spinal neurons and circuits generate startle behavior? And, how are gate transitions due to the physics of movement mediated neurally? To address these questions I examine reticulospinal and spinal interneuron morphology and function in zebrafish and examine comparatively species that differ in components of their startle neural circuits. A third area of research examines the evolution of neural circuits and behaviors. Through this work I am addressing the general question: How are neural circuits and behaviors modified evolutionarily? I examine the startle neural circuit in fishes comparatively within a phylogenetic context. In addition, mutant and transgenic zebrafish are providing new ways of addressing evolutionary questions such as this.
My approaches to these questions include using zebrafish as a model as well as comparative work on actinopterygian fishes. Larval zebrafish, in addition to being an excellent genetic system, are transparent which makes optical imaging of neuron morphology and activity as well as targeted neuron ablations possible in whole, in vivo preparations. With these techniques, we are able to combine functional imaging studies of neurons with behavior. In order to look simultaneously at neuron activity and fish movement, we label cells with calcium sensitive dyes and simultaneously image neurons firing with confocal microscopy and axial movements with high-speed video. With a complementary set of techniques, we kill neurons with cell targeted laser ablations and can compare behavior before and after the cells are removed. Because with such ablations we are able to very specifically remove cells without collateral damage, these techniques allow fine manipulation of the system.
SUNY
Stony Brook, NY
Postdoc - Neurobiology
2001
Grass Laboratory, Marine Biological Laboratory
Woods Hole, MA
Fellow - Neurobiology
2000
The University of Chicago
Chicago, IL
PhD - Biomechanics
1998
Duke University
Durham, NC
BS - Zoology
1992
Mechanosensory signal transmission in the arms and the nerve ring, an interarm connective, of Octopus bimaculoides.
Mechanosensory signal transmission in the arms and the nerve ring, an interarm connective, of Octopus bimaculoides. iScience. 2023 May 19; 26(5):106722.
PMID: 37216097
Multiple nerve cords connect the arms of octopuses, providing alternative paths for inter-arm signaling.
Multiple nerve cords connect the arms of octopuses, providing alternative paths for inter-arm signaling. Curr Biol. 2022 12 19; 32(24):5415-5421.e3.
PMID: 36446353
The Water to Land Transition Submerged: Multifunctional Design of Pectoral Fins for Use in Swimming and in Association with Underwater Substrate.
The Water to Land Transition Submerged: Multifunctional Design of Pectoral Fins for Use in Swimming and in Association with Underwater Substrate. Integr Comp Biol. 2022 10 29; 62(4):908-921.
PMID: 35652788
Extraoral Taste Buds on the Paired Fins of Damselfishes.
Extraoral Taste Buds on the Paired Fins of Damselfishes. Integr Org Biol. 2022; 4(1):obac035.
PMID: 36060866
Evolution of touch and proprioception of the limbs: Insights from fish and humans.
Evolution of touch and proprioception of the limbs: Insights from fish and humans. Curr Opin Neurobiol. 2021 12; 71:37-43.
PMID: 34562801
Sensing the structural characteristics of surfaces: texture encoding by a bottom-dwelling fish.
Sensing the structural characteristics of surfaces: texture encoding by a bottom-dwelling fish. J Exp Biol. 2020 11 03; 223(Pt 21).
PMID: 33144404
Hindbrain and Spinal Cord Contributions to the Cutaneous Sensory Innervation of the Larval Zebrafish Pectoral Fin.
Hindbrain and Spinal Cord Contributions to the Cutaneous Sensory Innervation of the Larval Zebrafish Pectoral Fin. Front Neuroanat. 2020; 14:581821.
PMID: 33192344
Morphological and physiological properties of Rohon-Beard neurons along the zebrafish spinal cord.
Morphological and physiological properties of Rohon-Beard neurons along the zebrafish spinal cord. J Comp Neurol. 2021 05 01; 529(7):1499-1515.
PMID: 32935362
DNA-based fluorescent probes of NOS2 activity in live brains.
DNA-based fluorescent probes of NOS2 activity in live brains. Proc Natl Acad Sci U S A. 2020 06 30; 117(26):14694-14702.
PMID: 32554491
Pectoral fin kinematics and motor patterns are shaped by fin ray mechanosensation during steady swimming in Scarus quoyi.
Pectoral fin kinematics and motor patterns are shaped by fin ray mechanosensation during steady swimming in Scarus quoyi. J Exp Biol. 2020 01 23; 223(Pt 2).
PMID: 31862848
President-Elect (2 years), President (2 years), Past-President (2 years)
Society for Integrative and Comparative Biology
2019 - 2025
Spokesperson (elected) of the Committee of the Council, Faculty Senate
The University of Chicago
2013 - 2014
Chair-elect (2 years), Chair (2 years), Past-Chair (2 years)
Society for Integrative and Comparative Biology’s Division of Comparative Biomechanics
2013 - 2019
Graduate Teaching and Mentoring Award
The University of Chicago
2012
Academic Leadership Program Fellow
(Center for Institutional Collaboration (Big10 plus))
2012 - 2013
Member of the Board
University of Chicago Press
2011 - 2014
Plenary speaker
International Congress on Vertebrate Morphology
2010
National Academies Education Fellow
2009 - 2010
Keynote Speaker
Stomatogastric Ganglion Meeting
2008
Defense Science Study Group Fellow
Institute for Defense Analysis
2006 - 2007
CAREER Award
National Science Foundation
2003
Grass Foundation Fellowship
Marine Biological Laboratory at Woods Hole
2000
National Research Service Award for Postdoctoral Research with J. R. Fetcho
1998
Scholarship
Bermuda Biological Station for Research
1995
Booth Prize for Excellence in Teaching
The University of Chicago
1994
Predoctoral Fellowship
Howard Hughes Medical Institute
1993 - 1998
Graduate Student Fellowship
University of Chicago
1992 - 1993
Dean's Merit Fellowship
The University of Chicago
1992 - 1998