Intrinsic mechanisms in the gating of resurgent Na+ currents

The resurgent component of the voltage-gated sodium current (

The value of ischemia-modified albumin compared with d-dimer in the diagnosis of pulmonary embolism

<p>Abstract</p> <p>Study objective</p> <p>The primary aim of this study was to investigate whether IMA levels are helpful in the diagnosis of pulmonary embolism (PE). The secondary aim was to determine whether IMA was more effective alone or in combination with clinical probability scores in the diagnosis of PE. Thirdly, the sensitivity and specificity of IMA is compared with D-dimer both with and without clinical probability scores in patients with suspected PE.</p> <p>Methods</p> <p>Consecutive patients presenting to the emergency department with suspected PE were prospectively recruited, and healthy volunteers were also enrolled as controls. D-dimer and IMA levels were measured for the entire study group. Wells and Geneva scores were calculated and s-CTPA was performed on all suspected PE patients.</p> <p>Results</p> <p>The study population consisted of 130 patients with suspected PE and 59 healthy controls. Mean IMA levels were 0.362 ± 0.11 ABSU for Group A, the PE group (n = 75); 0.265 ± 0.07 ABSU for Group B, the non-PE group (n = 55); and 0.175 ± 0.05 ABSU for Group C, the healthy control group (p < 0.0001). At a cut-off point of 0.25 ABSU, IMA was 93% sensitive and 75% specific in the diagnosis of PE. PPV was 79.4% and NPV was 78.6%. Mean D-dimer levels were 12.48 ± 10.88 μg/ml for Group A; 5.36 ± 7.80 μg/ml for Group B and 0.36 ± 0.16 μg/ml for Group C (p < 0.0001). The D-dimer cut-off point was 0.81 μg/ml with a sensitivity of 98.9% and a specificity of 62.7%, PPV of 69.4% and NPV of 83.3%. The use of IMA in combination with Wells and Geneva clinical probability scores was determined to have a positive impact on these scores' sensitivity and negative predictive values.</p> <p>Conclusion</p> <p>IMA is a good alternative to D-dimer in PE diagnosis in terms of both cost and efficiency. Used in combination with clinical probability scores, it has a similar positive effect on NPV and sensitivity to that of D-dimer. The PPV of IMA is better than D-dimer, but it is still unable to confirm a diagnosis of PE without additional investigation.</p

Psilocybin and Motor Function: A Triple‐Blind, Dose‐Finding Study in Healthy Participants

Background: There has been a resurgence of research into the potential therapeutic benefits of psychedelics for neuropsychiatric disorders. Classic psychedelics, such as psilocybin, exert complex effects on higher cognitive functions such as perception and awareness, but their impact on motor function remains unexplored. Moreover, there is a theoretical rationale for using psychedelics to promote motor retraining in certain neuropsychiatric conditions associated with motor dysfunction. This protocol paper outlines the first study to investigate the feasibility and safety of performing movement tasks during the acute effects of psilocybin in healthy participants. The findings from this study will further our understanding of the impact of psychedelics on motor function, and inform future studies that combine classic psychedelics with motor retraining in clinical populations. Methods: 12 healthy participants will each receive three doses of psilocybin (between 5 and 20 mg) in a randomized order, with each dose administered at least 1 week apart. Participants, the trial physiotherapists, and statisticians will remain blinded to the psilocybin dose. A battery of measures assessing motor function will be completed during the acute drug effects. In addition, measures of safety, pre‐ and post‐dose resting‐state brain activity via functional magnetic resonance imaging, and participants' subjective experience will be assessed

Psilocybin-Assisted Physiotherapy for Refractory Motor Functional Neurological Disorder: Protocol for a Randomised Dose-Comparison Pilot Study

Background: Motor functional neurological disorder (FND) is a common illness associated with significant functional impairment. There are no effective pharmacotherapies, and despite the early promise of physiotherapy studies, many suffer disabling symptoms in the long term. There is a theoretical rationale for combining psychedelics with physiotherapy; however, the potential benefit of this approach and optimal treatment model remains unexplored. Here, we present the protocol for the first study investigating the tolerability, feasibility, and potential efficacy of two distinct treatment regimens of psilocybin-assisted physiotherapy for refractory motor FND: a moderate dose that incorporates movement tasks during the acute drug effects versus a standard dose alone. Methods: Twenty-four participants with refractory motor FND will be randomised in a 1:1 ratio to either (1) psilocybin 15mg, with movement tasks conducted during the acute drug effects; or (2) psilocybin 25mg alone. All participants will receive two sessions of FND-specific physiotherapy pre-dosing, six sessions of physiotherapy post-dosing, and undergo follow-up visits one week and four weeks following their final physiotherapy session. A battery of outcome measures will be completed as scheduled, assessing tolerability, feasibility, motor FND symptom severity, psychiatric and physical symptoms, quality of life, treatment expectations, intensity of the acute drug effects, personality, motor function, force-matching performance, resting-state and task-based brain imaging, and subjective experiences of the study treatment. Discussion: These findings will assist the design of an adequately powered randomised controlled trial in this cohort. The findings may also inform the feasibility of psychedelic treatment in related functional and neuropsychiatric disorders

Bumblebees exhibit the memory spacing effect

Associative learning is key to how bees recognize and return to rewarding floral resources. It thus plays a major role in pollinator floral constancy and plant gene flow. Honeybees are the primary model for pollinator associative learning, but bumblebees play an important ecological role in a wider range of habitats, and their associative learning abilities are less well understood. We assayed learning with the proboscis extension reflex (PER), using a novel method for restraining bees (capsules) designed to improve bumblebee learning. We present the first results demonstrating that bumblebees exhibit the memory spacing effect. They improve their associative learning of odor and nectar reward by exhibiting increased memory acquisition, a component of long-term memory formation, when the time interval between rewarding trials is increased. Bombus impatiens forager memory acquisition (average discrimination index values) improved by 129% and 65% at inter-trial intervals (ITI) of 5 and 3 min, respectively, as compared to an ITI of 1 min. Memory acquisition rate also increased with increasing ITI. Encapsulation significantly increases olfactory memory acquisition. Ten times more foragers exhibited at least one PER response during training in capsules as compared to traditional PER harnesses. Thus, a novel conditioning assay, encapsulation, enabled us to improve bumblebee-learning acquisition and demonstrate that spaced learning results in better memory consolidation. Such spaced learning likely plays a role in forming long-term memories of rewarding floral resources

Generalization Mediates Sensitivity to Complex Odor Features in the Honeybee

Animals use odors as signals for mate, kin, and food recognition, a strategy which appears ubiquitous and successful despite the high intrinsic variability of naturally-occurring odor quantities. Stimulus generalization, or the ability to decide that two objects, though readily distinguishable, are similar enough to afford the same consequence [1], could help animals adjust to variation in odor signals without losing sensitivity to key inter-stimulus differences. The present study was designed to investigate whether an animal's ability to generalize learned associations to novel odors can be influenced by the nature of the associated outcome. We use a classical conditioning paradigm for studying olfactory learning in honeybees [2] to show that honeybees conditioned on either a fixed- or variable-proportion binary odor mixture generalize learned responses to novel proportions of the same mixture even when inter-odor differences are substantial. We also show that the resulting olfactory generalization gradients depend critically on both the nature of the stimulus-reward paradigm and the intrinsic variability of the conditioned stimulus. The reward dependency we observe must be cognitive rather than perceptual in nature, and we argue that outcome-dependent generalization is necessary for maintaining sensitivity to inter-odor differences in complex olfactory scenes