Biology subjects

Adewole, D. O.

Publications and source records attributed to Adewole, D. O..

3 recordsLinked to original sources

bioRxiv2021

Relationships between biomechanical parameters, neurological recovery, and neuropathology following concussion in swine

Mild traumatic brain injury (mTBI) affects millions of individuals annually primarily through falls, traffic collisions, or blunt trauma and can generate symptoms that persist for years. Closed-head rotational injury is the most common form of mTBI and is defined by a rapid change in acceleration within an intact skull. Injury kinematics - the mechanical descriptors of injury-inducing motion - explain movement of the head, energy transfer to the brain, and, therefore, determine injury severity. However, the relationship between closed-head rotational injury kinematics - such as angular velocity, angular acceleration, and injury duration - and outcome after mTBI is currently unknown. To address this gap in knowledge, we analyzed archived surgical records of 24 swine experiencing a diffuse closed-head rotational acceleration mTBI against 12 sham animals. Kinematics were contrasted against acute recovery outcomes, specifically apnea, extubation time, standing time, and recovery duration. Compared to controls, animals with mTBI were far more likely to have apnea (p<0.001) along with shorter time to extubation (p=0.023), and longer time from extubation to recovery (p=0.006). Using regression analyses with variable selection, we generated simplified linear models relating kinematics to apnea (R2=0.27), standing time (R2=0.39) and recovery duration (R2=0.42). Neuropathology was correlated with multiple kinematics, with maximum acceleration exhibiting the strongest correlation (R2=0.66). Together, these data suggest the interplay between multiple injury kinematics, including minimum velocity and middle to minimum acceleration time, best explain acute recovery parameters and neuropathology after mTBI in swine. Future experiments that independently manipulate individual kinematics could be instrumental in developing translational diagnostics for clinical mTBI.

neuroscience↗

bioRxiv2018

A Computational Model of Bidirectional Axonal Growth in Micro-Tissue Engineered Neuronal Networks (micro-TENNs)

Micro-Tissue Engineered Neural Networks (Micro-TENNs) are living three-dimensional constructs designed to replicate the neuroanatomy of white matter pathways in the brain, and are being developed as implantable microtissue for axon tract reconstruction or as anatomically-relevant in vitro experimental platforms. Micro-TENNs are composed of discrete neuronal aggregates connected by bundles of long-projecting axonal tracts within miniature tubular hydrogels. In order to help design and optimize micro-TENN performance, we have created a new computational model including geometric and functional properties. The model is built upon the three-dimensional diffusion equation and incorporates large-scale uni- and bi-directional growth that simulates realistic neuron morphologies. The model captures unique features of 3D axonal tract development that are not apparent in planar outgrowth, and may be insightful for how white matter pathways form during brain development. The processes of axonal outgrowth, branching, turning and aggregation/bundling from each neuron are described through functions built on concentration equations and growth time distributed across the growth segments. Once developed we conducted multiple parametric studies to explore the applicability of the method and conducted preliminary validation via comparisons to experimentally grown micro-TENNs for a range of growth conditions. Using this framework, this model can be applied to study micro-TENN growth processes and functional characteristics using spiking network or compartmental network modeling. This model may be applied to improve our understanding of axonal tract development and functionality, as well as to optimize the fabrication of implantable tissue engineered brain pathways for nervous system reconstruction and/or modulation.

bioengineering↗

bioRxiv2018

Optically-Controlled \"Living Electrodes\" with Long-Projecting Axon Tracts for a Synaptic Brain-Machine Interface

Achievements in intracortical neural interfaces are compromised by limitations in specificity and long-term performance. A biological intermediary between devices and the brain may offer improved specificity and longevity through natural synaptic integration with deep neural circuitry, while being accessible on the brain surface for optical read-out/control. Accordingly, we have developed the first "living electrodes" comprised of implantable axonal tracts protected within soft hydrogel cylinders for the biologically-mediated monitoring/modulation of brain activity. Here we demonstrate the controlled fabrication, rapid axonal outgrowth, reproducible cytoarchitecture, and simultaneous optical stimulation and recording of neuronal activity within these engineered constructs in vitro. We also present their transplantation, survival, integration, and optical recording in rat cortex in vivo as a proof-of-concept for this neural interface paradigm. The creation and functional validation of these preformed, axon-based "living electrodes" is a critical step towards developing a new class of biohybrid neural interfaces to probe and modulate native circuitry.

bioengineering↗