Nervous System Commons^™

Towards A New Role Of Mitochondrial Hydrogen Peroxide In Synaptic Function, Cliyahnelle Z. Alexander

Student Theses and Dissertations

Aerobic metabolism is known to generate damaging ROS, particularly hydrogen peroxide. Reactive oxygen species (ROS) are highly reactive molecules containing oxygen that have the potential to cause damage to cells and tissues in the body. ROS are highly reactive atoms or molecules that rapidly interact with other molecules within a cell. Intracellular accumulation can result in oxidative damage, dysfunction, and cell death. Due to the limitations of H₂O₂ (hydrogen peroxide) detectors, other impacts of ROS exposure may have been missed. HyPer7, a genetically encoded sensor, measures hydrogen peroxide emissions precisely and sensitively, even at sublethal levels, during …

Conditioned Place Avoidance Is Associated With A Distinct Hippocampal Phenotype, Partly Preserved Pattern Separation, And Reduced Reactive Oxygen Species Production After Stress, D. Parker Kelley, Lucas Albrechet-Souza, Shealan Cruise, Rajani Maiya, Aspasia Destouni, Siva S.V.P. Sakamuri, Alexander Duplooy, Meghan Hibicke, Charles Nichols, Prasad V.G. Katakam, Nicholas W. Gilpin, Joseph Francis

School of Medicine Faculty Publications

Stress is associated with contextual memory deficits, which may mediate avoidance of trauma-associated contexts in posttraumatic stress disorder. These deficits may emerge from impaired pattern separation, the independent representation of similar experiences by the dentate gyrus-Cornu Ammonis 3 (DG-CA3) circuit of the dorsal hippocampus, which allows for appropriate behavioral responses to specific environmental stimuli. Neurogenesis in the DG is controlled by mitochondrial reactive oxygen species (ROS) production, and may contribute to pattern separation. In Experiment 1, we performed RNA sequencing of the dorsal hippocampus 16 days after stress in rats that either develop conditioned place avoidance to a predator urine-associated …

High Energy Blue Light Induces Oxidative Stress And Retinal Cell Apoptosis, Jessica Malinsky

Capstone Showcase

Blue light (BL) is a high energy, short wavelength spanning 400 to 500 nm. Found in technological and environmental forms, BL has been shown to induce photochemical damage of the retina by reactive oxygen species (ROS) production. Excess ROS leads to oxidative stress, which disrupts retinal mitochondrial structure and function. As mitochondria amply occupy photoreceptors, they also contribute to oxidative stress due to their selectively significant absorption of BL at 400 to 500 nm. ROS generation that induces oxidative stress subsequently promotes retinal mitochondrial apoptosis. BL filtering and preventative mechanisms have been suggested to improve or repair BL-induced retinal damage, …

Measuring Mitochondrial Respiration In Vivo: From Mouse To Human, Arthur Orchanian, Brennan Schilling, Bruce Berkowitz Phd

Medical Student Research Symposium

Introduction: The mitochondrial energy ecosystem can be non-invasively interrogated in photoreceptors by combing a clinical tool, optical coherence tomography (OCT), with a mitochondrial protonophore (2,4 dinitrophenol, DNP). It remains unclear if only supra-clinical doses of DNP will be useful for mouse studies or if lower but clinically relevant doses of DNP would facilitate translation from mice to humans.

Methods: The experiment was a paired longitudinal design that took place over 2 days. On day 1, C57BL/6J mice were overnight dark adapted, then light-adapted for 5 h before OCT examination before regaining consciousness; a similar procedure was followed on day 2 …

Cardiac Arrest And Global Ischemia Reperfusion Injury: Role Of Mitochondria And Cannabinoid Receptor 2 Signaling., Jennifer L. Bradley

Theses and Dissertations

We explored the effects of cardiac arrest on mitochondria populations and heart whole tissue lysate proteomics utilizing the Weil Institute’s in vivo rat model of cardiac arrest and cardiopulmonary resuscitation. We have discovered that brain mitochondria are more sensitive to global ischemia compared to heart mitochondria. Additionally, complex I is the most sensitive electron transport chain complex to ischemic injury and is a major control point of the rate of oxidative phosphorylation following cardiac arrest and cardiopulmonary resuscitation. Preservation of brain mitochondrial activity and function during cardiac arrest may enhance outcomes and recovery.

A recent article focusing on acute myocardial …

Neuroprotective Strategies Following Experimental Traumatic Brain Injury: Lipid Peroxidation-Derived Aldehyde Scavenging And Inhibition Of Mitochondrial Permeability Transition, Jacqueline Renee Kulbe

Theses and Dissertations--Neuroscience

Traumatic brain injury (TBI) represents a significant health crisis. To date there are no FDA-approved pharmacotherapies available to prevent the neurologic deficits caused by TBI. Following TBI, dysfunctional mitochondria generate reactive oxygen and nitrogen species, initiating lipid peroxidation (LP) and the formation of LP-derived neurotoxic aldehydes, which bind mitochondrial proteins, exacerbating dysfunction and opening of the mitochondrial permeability pore (mPTP), resulting in extrusion of mitochondrial sequestered calcium into the cytosol, and initiating a downstream cascade of calpain activation, spectrin degradation, neurodegeneration and neurologic impairment.

As central mediators of the TBI secondary injury cascade, mitochondria and LP-derived neurotoxic aldehydes make promising …

Kinetics Of Dextromethorphan-O-Demethylase Activity And Distribution Of Cyp2d In Four Commonly-Used Subcellular Fractions Of Rat Brain, Barent N. Dubois, Farideh Amirrad, Reza Mehvar

Pharmacy Faculty Articles and Research

The purpose of this study was to compare the enzymatic kinetics and distribution of cytochrome P450 2D (CYP2D) among different rat brain subcellular fractions.

Rat brains were used to prepare total membrane, crude mitochondrial, purified mitochondrial, and microsomal fractions, in addition to total homogenate. Michaelis–Menten kinetics of the brain CYP2D activity was estimated based on the conversion of dextromethorphan (DXM) to dextrorphan using UPLC-MS/MS. Protein levels of CYP2D and subcellular markers were determined by Western blot.

Microsomal CYP2D exhibited high affinity and low capacity, compared with the mitochondrial CYP2D that had a much lower (∼50-fold) affinity but a higher (∼six-fold) …

Attenuating Trigeminal Neuropathic Pain By Repurposing Pioglitazone And D-Cycloserine In The Novel Trigeminal Inflammatory Compression Mouse Model, Danielle N. Lyons

Theses and Dissertations--Physiology

Approximately 22% of the United States population suffers from a chronic orofacial pain condition. One such condition is known as trigeminal neuropathic pain frequently reported as continuous aching and burning pain, often accompanied by intermittent electrical shock-like sensations. Dental procedures or trauma are known causes of peripheral trigeminal nerve injury and inflammation. Patients who have this type of facial pain also suffer from emotional distress. For these reasons, trigeminal neuropathic pain needs to be studied in more detail to improve the understanding of the etiology and maintenance of this condition, as well as to develop effective treatment strategies. The first …