Natural polymorphism in protein kinase G modulates functional senescence in Drosophilamelanogaster.

The common fruit fly, Drosophila melanogaster, is a well-characterized model for neurological disorders and is widely used to investigate the biology of aging, stress tolerance and pleiotropy. The foraging (for) gene encodes a cGMP-dependent protein kinase (PKG), which has been implicated in several behavioral phenotypes including feeding, sleep, learning and memory, and environmental stress tolerance. We used the well-established Drosophila activity monitor (DAM) to investigate the effects of the conserved NO/cGMP/PKG signaling pathway on functional senescence. Our results show that the polymorphic for gene confers protection during low oxygen stress at the expense of longevity and a decline in locomotor activity with age in D. melanogaster, which suggests a novel role for the PKG pathway in healthy aging and senescence.

Contribution of a natural polymorphism in protein kinase G modulates electroconvulsive seizure recovery in Drosophila melanogaster.

Drosophila melanogaster is a well-characterized model for neurological disorders and is widely used for investigating causes of altered neuronal excitability leading to seizure-like behavior. One method used to analyze behavioral output of neuronal perturbance is recording the time to locomotor recovery from an electroconvulsive shock. Based on this behavior, we sought to quantify seizure susceptibility in larval D. melanogaster with differences in the enzymatic activity levels of a major protein, cGMP-dependent protein kinase (PKG). PKG, encoded by foraging, has two natural allelic variants and has previously been implicated in several important physiological characteristics including: foraging patterns, learning and memory, and environmental stress tolerance. The well-established NO/cGMP/PKG signaling pathway found in the fly, which potentially targets downstream K+ channel(s), ultimately impacts membrane excitability, leading to our hypothesis: altering PKG enzymatic activity modulates time to recovery from an electroconvulsive seizure. Our results show that by both genetically and pharmacologically increasing PKG enzymatic activity, we can decrease the locomotor recovery time from an electroconvulsive seizure in larval D. melanogaster.

egl-4 modulates electroconvulsive seizure duration in C. elegans.

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 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.

Electroshock Induced Seizures in Adult C. elegans.

The nematode Caenorhabditis elegans is a useful model organism for dissecting molecular mechanisms of neurological diseases. While hermaphrodite C. elegans contains only 302 neurons, the conserved homologous neurotransmitters, simpler neuronal circuitry, and fully mapped connectome make it an appealing model system for neurological research. Here we developed an assay to induce an electroconvulsive seizure in C. elegans which can be used as a behavioral method of analyzing potential anti-epileptic therapeutics and novel genes involved in seizure susceptibility. In this assay, worms are suspended in an aqueous solution as current is passed through the liquid. At the onset of the shock, worms will briefly paralyze and twitch, and shortly after regain normal sinusoidal locomotion. The time to locomotor recovery is used as a metric of recovery from a seizure which can be reduced or extended by incorporating drugs that alter neuronal and muscular excitability.

Modulating Behavior in C. elegans Using Electroshock and Antiepileptic Drugs.

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 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.

Perspectives of academic faculty and clinical instructors on entry-level DPT preparation for pediatric physical therapist practice.

BACKGROUND: To prepare students for pediatric practice, the professional (entry-level) curriculum must reflect the essential knowledge, skills, and abilities (KSA) required for pediatric physical therapist practice. OBJECTIVES: The aim of this study was to develop consensus concerning the pediatric-specific KSA that should be expected of doctor of physical therapy (DPT) students at various points in the curriculum: prior to a pediatric clinical education experience, after a pediatric clinical education experience, and at the end of a DPT program. DESIGN AND METHODS: The study was conducted using the Delphi method. Purposive and snowball sampling were used to recruit pediatric academic faculty and pediatric clinical instructors. Three Web-based survey rounds were used to achieve consensus, defined as agreement among ≥70% of informants. The first round identified pediatric-specific KSA that were essential for DPT students to demonstrate at the identified points in the curriculum. In the second round, informants indicated their level of agreement with each item identified in the first round. Items that achieved consensus were included in the third round, in which informants rated the level of proficiency that DPT students should demonstrate related to pediatric-specific KSA. RESULTS: Consensus revealed the informants' perspectives concerning pediatric-specific KSA that a DPT student should be able to demonstrate at the identified curricular points. Consensus was reached on items in the curricular categories of basic science and foundations for practice; common pediatric diagnoses/pathologies, examination, interventions/plan of care/documentation; and general skills and abilities. LIMITATIONS: Limitations included the small sample size and the potential for informants to feel uncomfortable prioritizing KSA. CONCLUSIONS: This study is an initial step toward identifying pediatric-specific KSA that should be demonstrated by DPT students.

Effects of an intensive, task-specific rehabilitation program for individuals with chronic stroke: a case series.

PURPOSE: The purpose of this case series was to determine feasibility and evaluate changes in activity and participation outcomes in persons with chronic stroke after an intensive, task-specific rehabilitation program incorporating whole-body and client-centred interventions. METHOD: Participants with chronic stroke (N = 12) who were ambulatory and had at least minimal arm/hand function were recruited. The program included whole-body goal-focused activities, gait training and strengthening exercises for 4 h, 5 days per week for 2 weeks. Daily educational sessions and a home activities program were also included. Activity-based measures including the Wolf motor function test, Berg balance scale, timed up and go test and 6-min walk test and participation-based measures including the Stroke Impact Scale and Canadian Occupational Performance Measure were collected at pre-test, immediate post-test and 5-month retention. RESULTS: The effect of the intervention on participation-based outcomes was much greater than on the activity-based outcomes. Minimal detectable differences in self-perceived participation were reported for most participants. CONCLUSIONS: The intensive, task-specific intervention was a feasible program for these participants with stroke. Although minimal changes in activity-based outcomes were found, the participants perceived improvements in participation with personal goal-related activities that resulted in large effect sizes that were maintained for 5-months after the intervention.