Current Search: Risley, Monica G. (x)
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- Title
- Pushing the limit: Examining factors that affect anoxia tolerance in a single genotype of adult D. melanogaster.
- Creator
- Benasayag Meszaros, Raquel, Risley, Monica G., Hernandez, Priscilla, Fendrich, Margo, Dawson-Scully, Ken
- Abstract/Description
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Drosophila melanogaster is a promiscuous species that inhabits a large range of harsh environments including flooded habitats and varying temperature changes. To survive these environments, fruit flies have adapted mechanisms of tolerance that allow them to thrive. During exposure to anoxic stress, fruit flies and other poikilotherms enter into a reversible, protective coma. This coma can be manipulated based on controlled environmental conditions inside the laboratory. Here we utilize a...
Show moreDrosophila melanogaster is a promiscuous species that inhabits a large range of harsh environments including flooded habitats and varying temperature changes. To survive these environments, fruit flies have adapted mechanisms of tolerance that allow them to thrive. During exposure to anoxic stress, fruit flies and other poikilotherms enter into a reversible, protective coma. This coma can be manipulated based on controlled environmental conditions inside the laboratory. Here we utilize a common laboratory raised strain of D. melanogaster to characterize adaptation abilities to better understand coma recovery and survival limitations. Our goal is to mimic the fly’s natural environments (wet anoxia) and relate findings to a typical gas induced environment (dry anoxia) that is commonly used in a laboratory. Despite the abundance of research regarding acute and chronic anoxic exposure and cold stress, the literature is lacking evidence linking anoxic stress with variable environmental conditions such as animal age and stress duration. We present novel ways to assess coma recovery and survival using readily available laboratory tools. Our findings suggest that younger age, exposure to colder temperatures and wet environments increase resistance to anoxic stress.
Show less - Date Issued
- 2015-08-17
- PURL
- http://purl.flvc.org/fau/fd/FAUIR000065
- Format
- Citation
- Title
- Characterizing electroconvulsive seizure recovery time in the invertebrate model systems Caenorhabditis elegans and Drosophila melanogaster.
- Creator
- Risley, Monica G., Dawson-Scully, Ken, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Seizures are a symptom of epilepsy, characterized by spontaneous firing due to an imbalance of excitatory and inhibitory features. While mammalian seizure models receive the most attention, the simplicity and tractability of invertebrate model systems, specifically C. elegans and D. melanogaster, have many advantages in understanding the molecular and cellular mechanisms of seizure behavior. This research explores C. elegans and D. melanogaster as electroconvulsive seizure models to...
Show moreSeizures are a symptom of epilepsy, characterized by spontaneous firing due to an imbalance of excitatory and inhibitory features. While mammalian seizure models receive the most attention, the simplicity and tractability of invertebrate model systems, specifically C. elegans and D. melanogaster, have many advantages in understanding the molecular and cellular mechanisms of seizure behavior. This research explores C. elegans and D. melanogaster as electroconvulsive seizure models to investigate methods to both modulate and better understand seizure susceptibility. A common underlying feature of seizures in mammals, worms, and flies involves regulating excitation and inhibition. The C. elegans locomotor circuit is regulated via well characterized GABAergic and cholingeric motoneurons that innervate two rows of dorsal and ventral body wall muscles. In this research, we developed an electroconvulsive seizure assay which utilizes the locomotor circuit as a behavioral read out of neuronal function. When inhibition is decreased in the circuit, for example by decreasing GABAergic input, we find a general increase in the time to recovery from a seizure. After establishing the contribution of excitation and inhibition to seizure recovery, we explored a ubiquitin ligase, associated with comorbidity of an X-linked Intellectual Disorder and epilepsy in humans, and established that the worm homolog, eel-1, contributes to seizure susceptibility similarly to the human gene. Next, we investigated a cGMP-dependent protein kinase (PKG) that functions in the nervous system of both worms and flies and determined that increasing PKG activity, decreases the time to recovery from an electroconvulsive seizure. These experiments suggest a potential novel role for a major protein, PKG, in seizure susceptibility and that the C. elegans and D. melanogaster electroconvulsive seizure assays can be used to investigate possible genes involved in seizure susceptibility and future therapeutic to treat epilepsy.
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00005954
- Subject Headings
- Seizures, Epilepsy, Drosophila melanogaster, Caenorhabditis elegans
- Format
- Document (PDF)
- Title
- The HECT Family Ubiquitin Ligase EEL-1 Regulates Neuronal Function and Development.
- Creator
- Opperman, Karla J., Mulcahy, Ben, Giles, Andrew C., Risley, Monica G., Birnbaum, Rayna L., Tulgren, Erik D., Dawson-Scully, Ken, Zhen, Mei, Grill, Brock
- Date Issued
- 2017-04
- PURL
- http://purl.flvc.org/fau/flvc_fau_islandoraimporter_10.1016_j.celrep.2017.04.003_1644939781
- Format
- Document (PDF)
- Title
- Modulating Behavior in C. elegans Using Electroshock and Antiepileptic Drugs.
- Creator
- Monica G. Risley, Stephanie P. Kelly, Kailiang Jia, Brock Grill, Ken Dawson- Scully
- Abstract/Description
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The microscopic nematode Caenorhabditis elegans has emerged as a valuable model for understanding the molecular and cellular basis of neurological disorders. The worm offers important physiological similarities to mammalian models such as conserved neuron morphology, ion channels, and neurotransmitters. While a wide-array of behavioral assays are available in C. elegans, an assay for electroshock/electroconvulsion remains absent. Here, we have developed a quantitative behavioral method to...
Show moreThe microscopic nematode Caenorhabditis elegans has emerged as a valuable model for understanding the molecular and cellular basis of neurological disorders. The worm offers important physiological similarities to mammalian models such as conserved neuron morphology, ion channels, and neurotransmitters. While a wide-array of behavioral assays are available in C. elegans, an assay for electroshock/electroconvulsion remains absent. Here, we have developed a quantitative behavioral method to assess the locomotor response following electric shock in C. elegans. Electric shock impairs normal locomotion, and induces paralysis and muscle twitching; after a brief recovery period, shocked animals resume normal locomotion. We tested electric shock responses in loss-of-function mutants for unc-25, which encodes the GABA biosynthetic enzyme GAD, and unc-49, which encodes the GABAA receptor. unc-25 and unc-49 mutants have decreased inhibitory GABAergic transmission to muscles, and take significantly more time to recover normal locomotion following electric shock compared to wild-type. Importantly, increased sensitivity of unc-25 and unc-49 mutants to electric shock is rescued by treatment with antiepileptic drugs, such as retigabine. Additionally, we show that pentylenetetrazol (PTZ), a GABAA receptor antagonist and proconvulsant in mammalian and C. elegans seizure models, increases susceptibility of worms to electric shock.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FAUIR000530
- Format
- Document (PDF)
- Title
- egl‑4 modulates electroconvulsive seizure duration in C. elegans.
- Creator
- Monica G. Risley, Stephanie P. Kelly, Justin Minnerly, Kailiang Jia, Ken Dawson‑Scully
- Abstract/Description
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Increased neuronal excitability causes seizures with debilitating symptoms. Effective and noninvasive treatments are limited for easing symptoms, partially due to the complexity of the disorder and lack of knowledge of specific molecular faults. An unexplored, novel target for seizure therapeutics is the cGMP/protein kinase G (PKG) pathway, which targets downstream K+ channels, a mechanism similar to Retigabine, a recently FDA-approved antiepileptic drug. Our results demonstrate that...
Show moreIncreased neuronal excitability causes seizures with debilitating symptoms. Effective and noninvasive treatments are limited for easing symptoms, partially due to the complexity of the disorder and lack of knowledge of specific molecular faults. An unexplored, novel target for seizure therapeutics is the cGMP/protein kinase G (PKG) pathway, which targets downstream K+ channels, a mechanism similar to Retigabine, a recently FDA-approved antiepileptic drug. Our results demonstrate that increased PKG activity decreased seizure duration in C. elegans utilizing a recently developed electroconvulsive seizure assay. While the fly is a well-established seizure model, C. elegans are an ideal yet unexploited model which easily uptakes drugs and can be utilized for high-throughput screens. In this study, we show that treating the worms with either a potassium channel opener, Retigabine or published pharmaceuticals that increase PKG activity, significantly reduces seizure recovery times. Our results suggest that PKG signaling modulates downstream K+ channel conductance to control seizure recovery time in C. elegans. Hence, we provide powerful evidence, suggesting that pharmacological manipulation of the PKG signaling cascade may control seizure duration across phyla.
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FAUIR000532
- Format
- Document (PDF)