We study how injury and rehabilitative exercise modulates pain and sensorimotor function following spinal cord injury. We use a multidisciplinary approach which includes assessments of animal behavior, kinematics and electrophysiology as well as assessments of molecular changes in neuron and immune cell phenotypes. Active lines of research ongoing in the lab include:
Neuroimmune interactions associated with pain development after injury
Traumatic injury to the spinal cord induces a robust immune and inflammatory response at the site of primary injury. Recent evidence from our lab and others suggests that these responses are not limited to the site of injury, but rather extend to remote regions of the spinal cord, brain and dorsal root ganglia. We are focused on understanding how a specific type of immune cells called macrophages interact with pain-sensing neurons after injury to result in their dysfunction.
Nociceptor dysfunction associated with cerebral palsy and chronic pain
Cerebral palsy is a movement disorder that is often caused by injuries during prenatal development or birth. In addition to permanent motor impairments, individuals with CP often report chronic pain. We have begun to explore alterations in pain and sensory function as well as nociceptor plasticity in animal models of cerebral palsy.
Role of primary afferent plasticity in recovery of function after traumatic injury
Primary afferent input into the spinal cord is an important component for motor control. After injury, activity-dependent therapies like physical therapy and rehabilitation are the standard of care for individuals who have sustained a spinal cord injury. Rehabilitation paradigms often provide repetitive, primary afferent driven cues to spinal circuitry to drive motor output. In the lab, we use animal models of both injury and rehabilitation to understand how aerobic, resistance or range-of-motion exercises can induce plasticity or alterations in the anatomical and functional properties of primary afferent neurons and spinal cord circuitry that controls movements like reaching and grasping.
Current Lab Members
- Jonathan Richards, PhD
- John Walker, MS
Neuroscience PhD Student
- Jason Wheeler, MS
Neuroscience PhD Student
- Meredith Singer, MS
Lab Manager
- Grace Giddings
Neuroscience PhD Student
- Jordan Dowtin-Dorsey
Post-Bacc Student
- Ameer Ghaderi
Post-Bacc Student
- Andrea Roguer
Post-Bacc Student
Lab Alumni
- Soha Chhaya, BS, PhD
- Daniel Freeman, BS/MS
- Amy Ong, MS
- Chloe Metz, BS
Collaborators Within Drexel
External Collaborators
- Jeoung Soo Lee
Department of Bioengineering, Clemson University
- Katharina A. Quinlan
George and Anne Ryan Institute for Neuroscience, University of Rhode Island
- John Bethea
Department of Anatomy and Cell Biology, George Washington University School of Medicine & Health Sciences
Personal Diversity, Equity and Inclusion Statement
One of the challenges I face as faculty is to eradicate the pervasive, stereotypical image of a scientist as an older white man (with or without Einstein-like hair) wearing a lab coat. As a young person trying to find my way, I was given an opportunity and subsequently found neurotrauma. I can honestly say that the power of strong mentorship that included giving a young, inexperienced person an opportunity in an unknown field changed my trajectory. I have set up and run my lab to be a place of opportunity for individuals to discover if science and research is their purpose. I provide a positive and welcoming environment, where open discussion about ideas and opinions is encouraged. My only requirement is that everyone in the lab must agree to “disagree respectfully,” and that prejudice against anyone on the basis of their identity won’t be tolerated. At any time, my lab members range from high schoolers to retirees, come from diverse racial, ethnic, religious, and socioeconomic backgrounds and have varied educational focuses and interests that include: neuroscience, engineering, psychology, molecular biology, health sciences and even anthropology.
I come from a long line of schoolteachers, and I have been actively participating in community and school outreach programs related to STEM and neuroscience education since I was in school myself. With other graduate students of the Neuroscience Graduate Studies Program at Ohio State University, we founded an outreach program that brings neuroscience to local grade schools to demystify neuroscience and encourage children to think about pursuing science. I am proud to say that when I attended the annual retreat for the NGP at Ohio State in 2021, that I learned that the program was still active, and I couldn’t be more proud. At Drexel, I have continued to participate in outreach activities through the Medical Student For A Day Program and the Biomedical Graduate Students for Diversity Program. For my trainees and those within the Neurobiology and Anatomy Department at Drexel, I invite seminar speakers with diverse backgrounds and ethnicities, because representation matters.
Techniques
Students currently have the opportunity to learn a wide variety of behavioral and neuroanatomical techniques in the lab:
- Surgical: Stereotactic brain and spinal cord surgery, infusions of neurotoxins, retrograde and anterograde fluorescent labeling.
- Behavioral: Sensory testing, use of the BBB and FLS locomotor rating scales, gait analysis, development of rehabilitative strategies for functional recovery.
- Neuroanatomical: Immunocytochemistry, tract tracing, stereologic cell counting.
- Molecular: quantitative-PCR, microarray analysis of microRNA, Western blot, ELISA, flow cytometry, FACS.
- Electrophysiological: Whole-cell patch electrophysiology, intraspinal recording, EMG recording.
Active Funding
NIH NINDS #NS097880 (years 5-10)
Principal Investigator
Title: Regulation of neuropathic pain by exercise: effects on nociceptor plasticity and inflammation
The overall objective of this proposal is to determine the how exercise alters the role of myeloid cells (macrophages) that infiltrate the dorsal root ganglia after a spinal cord injury to affect nociceptor excitability and the development and persistence of neuropathic pain.
NIH NINDS #RF1NS135580
Co-Principal Investigator
Title: Validation of prenatal rabbit hypoxia ischemia as a model of cerebral palsy-induced pain
The overall objective of this proposal is to determine if the prenatal rabbit hypoxia ischemia which mimics motor dysfunctions of people living with cerebral palsy also emulates the chronic pain that develops over these individuals’ lifetimes. Rigorous experiments will determine face, criterion and construct validity.
Craig H. Neilsen Foundation #1001637
Principal Investigator
Title: Macrophage-targeted nanotherapeutic to reduce SCI Pain
The overall objective of this proposal is to provide necessary preliminary data and establish the feasibility of ED1-PgP-Rm as a therapeutic to treat and provide relief to individuals living with chronic SCI pain.
Lab News
On December 15, 2023, Jonathan Richards successfully defended his dissertation entitled, “Neuroimmune Contributions to Mouse Chronic Neuropathic Pain: Macrophages Play a Dual Role in Sensory Discriminative and Affective Components of Pain.” Congratulations, Dr. Richards!
Jason Wheeler, Neuroscience PhD student in the lab was awarded a fellowship on the NIH-funded T32 training program in spinal cord injury. The fellowship will provide funding for up to two years.
Daniel Freeman successfully defended his MS dissertation entitled, “The Plasticity of Intercellular Communication and The Polarization of Glial Cells in Pain Centers Following Spinal Cord Injury,” on Monday, June 5, 2023. Daniel will be heading to University of Maryland—Baltimore to pursue a PhD in Neuroscience next fall.
Jason Wheeler received his MS degree in Neuroscience from Drexel University College of Medicine on May 11, 2023.
Lab members, Daniel Freeman, BS/MS Biology student, and Neuroscience PhD students Jonathan Richards, BS, John Walker, MS and Jason Wheeler, BS presented posters of their ongoing work at the International Symposium for Neural Regeneration Meeting in April, 2023 at Skamania Lodge in Stevenson, Washington.
John Walker, MS, Neuroscience PhD candidate in the Detloff Lab, delivered a DataBlitz, “Nociception Impedes Grasping Recovery in the Spinal Cord Injured Rat,” at the Society for the Neural Control of Movement Conference 2022 in Dublin, Ireland, on August 28.
Jason Wheeler, Neuroscience master’s student in the Detloff Lab, presented a poster, “Intrathecal Injection of Polarized Macrophage Exosomes Reduces Mechanical and Thermal Pain Sensation in Spinal Cord Injured Rats,” at the World Congress for the International Association for the Study of Pain in Toronto, Ontario, on September 21, 2022.