Traumatic brain injury (TBI) remains a major public health problem and is on pace to become the third leading cause of death and disability in the world population by 2020. Although we know that both neuronal degeneration and cognitive deficits are common features of human TBI, we are only beginning to appreciate an entirely new dimension of the disease: how brain networks change immediately after injury, and how cognitive recovery may depend critically on rebuilding these networks. The broad, long-term goal of our work identifies the fundamental mechanisms on how neural activity and intracellular signaling pathways together contribute to rebuilding a circuit after TBI. To our knowledge, our preliminary data is the first evidence showing how the structure of neural circuits changes after TBI, and the first observation on how combining circuit activation with pharmaceutics can together rebuild a network. We build on our preliminary data and propose the following aims:
Specific Aim 1 : To examine mechanisms of neuronal disconnection from a network after mechanical injury in vitro and in vivo.
Specific Aim 2 : To determine mechanisms for the activity-induced re-integration of neurons into an injured microcircuit over time, extending this into measuring circuit remodeling in awake, behaving animals subjected to TBI. Our general hypotheses are: (a) Connectivity directly influences neuronal disconnection from a network following injury, as well as network recovery (b) neuronal re-integration into the network is mediated by calcineurin activity and CREB-phosphorylation, (c) neuronal disconnection is mediated by mitochondrial signaling, and (d) prolonged circuit activation, in combination with pharmaceutics, can optimally control the reconstruction of networks. Impact: Knowing the mechanisms for remodeling neuronal connections in a circuit over time after TBI will give us insight into treatments protecting the network structure. Once the mechanisms for remodeling circuitry in the living brain after TBI are better understood, we envision testing therapies in preclinical TBI models within the next 5-10 years. Broadly, we believe this work will shift the therapeutic focus away from reducing neuronal death and towards approaches to rebuild functional circuits after TBI.

Public Health Relevance

Traumatic brain injury (TBI) is a pervasive public health problem, yet we know very little about how changes to brain networks relate to the cognitive deficits in TBI patients. In this project, we study how the changes in the wiring and connection strength among neurons in a circuit change after TBI, and we identify the key mechanisms that regulate the remodeling of these connections. Our goal is to understand how to optimize the remodeling of neural circuits to accelerate recovery after TBI.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS088176-03
Application #
9325615
Study Section
Brain Injury and Neurovascular Pathologies Study Section (BINP)
Program Officer
Bellgowan, Patrick S F
Project Start
2015-09-01
Project End
2019-07-31
Budget Start
2017-08-01
Budget End
2018-07-31
Support Year
3
Fiscal Year
2017
Total Cost
Indirect Cost
Name
University of Pennsylvania
Department
Biomedical Engineering
Type
Biomed Engr/Col Engr/Engr Sta
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Vogel 3rd, Edward W; Morales, Fatima N; Meaney, David F et al. (2017) Phosphodiesterase-4 inhibition restored hippocampal long term potentiation after primary blast. Exp Neurol 293:91-100
Wiles, Laura; Gu, Shi; Pasqualetti, Fabio et al. (2017) Autaptic Connections Shift Network Excitability and Bursting. Sci Rep 7:44006
Cullen, D Kacy; Harris, James P; Browne, Kevin D et al. (2016) A Porcine Model of Traumatic Brain Injury via Head Rotational Acceleration. Methods Mol Biol 1462:289-324
Effgen, Gwen B; Ong, Tiffany; Nammalwar, Shruthi et al. (2016) Primary Blast Exposure Increases Hippocampal Vulnerability to Subsequent Exposure: Reducing Long-Term Potentiation. J Neurotrauma 33:1901-1912
Vogel 3rd, Edward W; Effgen, Gwen B; Patel, Tapan P et al. (2016) Isolated Primary Blast Inhibits Long-Term Potentiation in Organotypic Hippocampal Slice Cultures. J Neurotrauma 33:652-61
Ko, Jina; Hemphill, Matthew A; Gabrieli, David et al. (2016) Smartphone-enabled optofluidic exosome diagnostic for concussion recovery. Sci Rep 6:31215
Beamer, Matthew; Tummala, Shanti R; Gullotti, David et al. (2016) Primary blast injury causes cognitive impairments and hippocampal circuit alterations. Exp Neurol 283:16-28
Patel, Tapan P; Man, Karen; Firestein, Bonnie L et al. (2015) Automated quantification of neuronal networks and single-cell calcium dynamics using calcium imaging. J Neurosci Methods 243:26-38
Kang, Woo Hyeun; Cao, Wenzhe; Graudejus, Oliver et al. (2015) Alterations in Hippocampal Network Activity after In Vitro Traumatic Brain Injury. J Neurotrauma 32:1011-9
Meaney, David F; Smith, Douglas H (2015) Cellular biomechanics of central nervous system injury. Handb Clin Neurol 127:105-14

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