Mild Transient Hypercapnia as a Novel Fear Conditioning Stimulus Allowing Re-Exposure during Sleep

Introduction:Studies suggest that sleep plays a role in traumatic memories and that treatment of sleep disorders may help alleviate symptoms of posttraumatic stress disorder. Fear-conditioning paradigms in rodents are used to investigate causal mechanisms of fear acquisition and the relationship between sleep and posttraumatic behaviors. We developed a novel conditioning stimulus (CS) that evoked fear and was subsequently used to study re-exposure to the CS during sleep.Methods:Experiment 1 assessed physiological responses to a conditioned stimulus (mild transient hypercapnia, mtHC; 3.0% CO2; n = 17)+footshock for the purpose of establishing a novel CS in male FVB/J mice. Responses to the novel CS were compared to tone+footshock (n = 18) and control groups of tone alone (n = 17) and mild transient hypercapnia alone (n = 10). A second proof of principle experiment re-exposed animals during sleep to mild transient hypercapnia or air (control) to study sleep processes related to the CS.Results:Footshock elicited a response of acute tachycardia (30-40 bpm) and increased plasma epinephrine. When tone predicted footshock it elicited mild hypertension (1-2 mmHg) and a three-fold increase in plasma epinephrine. When mtHC predicted footshock it also induced mild hypertension, but additionally elicited a conditioned bradycardia and a smaller increase in plasma epinephrine. The overall mean 24 hour sleep-wake profile was unaffected immediately after fear conditioning.Discussion:Our study demonstrates the efficacy of mtHC as a conditioning stimulus that is perceptible but innocuous (relative to tone) and applicable during sleep. This novel model will allow future studies to explore sleep-dependent mechanisms underlying maladaptive fear responses, as well as elucidate the moderators of the relationship between fear responses and sleep. © 2013 McDowell et al

An international definition for "nursing home"

There is much ambiguity regarding the term “nursing home” in the international literature. The definition of a nursing home and the type of assistance provided in a nursing home is quite varied by country. The International Association of Gerontology and Geriatrics and AMDA foundation developed a survey to assist with an international consensus on the definition of “nursing home.”Sin financiación6.616 JCR (2015) Q1, 2/49 Geriatrics & GerontologyUE

Community-led non-invasive polar bear monitoring in the Eeyou Marine Region of James Bay, Canada: insights on distribution and body condition during the ice-free season

Wildlife conservation is informed by detailed understanding of species demographics, habitat use, and interactions with environmental drivers. Challenges to collecting this information, particularly in remote places and on widely ranging species, can contribute to data deficiencies that detract from conservation status assessment and the effectiveness of management actions. Polar bears in James Bay face rapidly changing environmental conditions at the southern edge of their global range, but studying their ecology has been limited by community concerns about the methods typically used in polar bear research. Using a community-led and non-invasive approach, we deployed hair snare and camera trap sampling stations across 400 km of the Eeyou Marine Region in eastern James Bay. Stations collected >100 hair samples and thousands of photographs in one eight-week period that allowed for a novel investigation of this population’s distribution and body condition during the ice-free season. Polar bears were in average to above average body condition, and model selection of detections at stations revealed distance to mainland as a significant predictor of polar bear presence. Given its high potential, we suggest community-based monitoring using this method become a standard protocol to expand the scope and local leadership of polar bear research across the North

Early removal of the infrapatellar fat pad/synovium complex beneficially alters the pathogenesis of moderate stage idiopathic knee osteoarthritis in male Dunkin Hartley guinea pigs

Abstract Background The infrapatellar fat pad (IFP) is the largest adipose deposit in the knee; however, its contributions to the homeostasis of this organ remain undefined. To determine the influence of the IFP and its associated synovium (IFP/synovium complex or IFP/SC) on joint health, this study evaluated the progression of osteoarthritis (OA) following excision of this unit in a rodent model of naturally-occurring disease. Methods Male Dunkin-Hartley guinea pigs (n=18) received surgical removal of the IFP in one knee at 3 months of age; contralateral knees received sham surgery as matched internal controls. Mobility and gait assessments were performed prior to IFP/SC removal and monthly thereafter. Animals were harvested at 7 months of age. Ten set of these knees were processed for microcomputed tomography (microCT), histopathology, transcript expression analyses, and immunohistochemistry (IHC); 8 sets of knees were dedicated to microCT and biomechanical testing (material properties of knee joints tissues and anterior drawer laxity). Results Fibrous connective tissue (FCT) developed in place of the native adipose depot. Gait demonstrated no significant differences between IFP/SC removal and contralateral hindlimbs. MicroCT OA scores were improved in knees containing the FCT. Quantitatively, IFP/SC-containing knees had more osteophyte development and increased trabecular volume bone mineral density (vBMD) in femora and tibiae. Histopathology confirmed maintenance of articular cartilage structure, proteoglycan content, and chondrocyte cellularity in FCT-containing knees. Transcript analyses revealed decreased expression of adipose-related molecules and select inflammatory mediators in FCTs compared to IFP/SCs. This was verified via IHC for two key inflammatory agents. The medial articular cartilage in knees with native IFP/SCs showed an increase in equilibrium modulus, which correlated with increased amounts of magnesium and phosphorus. Discussion/conclusion Formation of the FCT resulted in reduced OA-associated changes in both bone and cartilage. This benefit may be associated with: a decrease in inflammatory mediators at transcript and protein levels; and/or improved biomechanical properties. Thus, the IFP/SC may play a role in the pathogenesis of knee OA in this strain, with removal prior to disease onset appearing to have short-term benefits