Increased robustness and adaptation to simultaneous temperature and elevated extracellular potassium in the pyloric rhythm of the crab, .

Animals must deal with numerous perturbations, oftentimes concurrently. In this study, we examine the effects of two perturbations, high extracellular potassium and elevated temperature, on the resilience of the pyloric rhythm of the crab, . At control temperatures (11°C), high potassium saline (2.

Imperatives and co-benefits of research into climate change and neurological disease.

Evidence suggests that anthropogenic climate change is accelerating and is affecting human health globally. Despite urgent calls to address health effects in the context of the additional challenges of environmental degradation, biodiversity loss and ageing populations, the effects of climate change on specific health conditions are still poorly understood. Neurological diseases contribute substantially to the global burden of disease, and the possible direct and indirect consequences of climate change for people with these conditions are a cause for concern.

Degenerate neuronal and circuit mechanisms important for generating rhythmic motor patterns.

In 1996, we published a review article (Marder E, Calabrese RL. 76: 687-717, 1996) describing the state of knowledge about the structure and function of the central pattern-generating circuits important for producing rhythmic behaviors. Although many of the core questions persist, much has changed since 1996.

What happened to the pursuit of truth?

The knowledge in our brains, not in our phones, is necessary for creative thinking and the pursuit of truth.

Spatiotemporal Cluster Detection for COVID-19 Outbreak Surveillance: Descriptive Analysis Study.

Background: During the peak of the winter 2020-2021 surge, the number of weekly reported COVID-19 outbreaks in Washington State was 231; the majority occurred in high-priority settings such as workplaces, community settings, and schools. The Washington State Department of Health used automated address matching to identify clusters at health care facilities. No other systematic, statewide outbreak detection methods were in place.

I block reveals separation of timescales in pyloric rhythm response to temperature changes in .

Motor systems operate over a range of frequencies and relative timing (phase). We studied the role of the hyperpolarization-activated inward current (I) in regulating these features in the pyloric rhythm of the stomatogastric ganglion (STG) of the crab, as temperature was altered from 11°C to 21°C. Under control conditions, rhythm frequency increased monotonically with temperature, while the phases of the pyloric dilator (PD), lateral pyloric (LP), and pyloric (PY) neurons remained constant.

The Brain's Best Kept Secret Is Its Degenerate Structure.

Degeneracy is defined as multiple sets of solutions that can produce very similar system performance. Degeneracy is seen across phylogenetic scales, in all kinds of organisms. In neuroscience, degeneracy can be seen in the constellation of biophysical properties that produce a neuron's characteristic intrinsic properties and/or the constellation of mechanisms that determine circuit outputs or behavior.

Sulfonylurea Receptor Pharmacology Alters the Performance of Two Central Pattern Generating Circuits in Cancer borealis.

Neuronal activity and energy supply must maintain a fine balance for neuronal fitness. Various channels of communication between the two could impact network output in different ways. Sulfonylurea receptors (SURs) are a modification of ATP-binding cassette proteins that confer ATP-dependent gating on their associated ion channels.

Circuit function is more robust to changes in synaptic than intrinsic conductances.

Circuit function results from both intrinsic conductances of network neurons and the synaptic conductances that connect them. In models of neural circuits, different combinations of maximal conductances can give rise to similar activity. We compared the robustness of a neural circuit to changes in their intrinsic versus synaptic conductances.

Sulfonylurea receptor coupled conductances alter the performace of two central pattern generating circuits in .

Neuronal activity and energy supply must maintain a fine balance for neuronal fitness. Various channels of communication between the two could impact network output in different ways. Sulfonylurea receptors (SURs) are a modification of ATP-binding cassette proteins (ABCs) that confer ATP-dependent gating on their associated ion channels.

The 2018-2019 FoodNet Population Survey: a tool to estimate risks and behaviors associated with enteric infections.

The FoodNet Population Survey is a periodic survey of randomly selected residents at 10 US sites on exposures and behaviors that may be associated with acute diarrheal infections and the health care sought for those infections. This survey is used to estimate the true disease burden of enteric illness in the United States and to estimate rates of exposure to potential sources of illness. Unlike previous FoodNet Population Surveys, this cycle used multiple sampling frames and administration modes, including cell phone and web-based questionnaires, that allowed for additional question topics and a larger sample size.

Resilience of circuits to environmental challenge.

Animals of all kinds evolved to deal with anticipated and unanticipated changes in a variety of features in their environments. Consequently, all environmental perturbations, adaptations, and acclimation involve a myriad of factors that, together, contribute to environmental resilience. New work highlights the importance of neuromodulation in the control of environmental resilience, and illustrates that different components of the nervous system may be differentially resilient to environmental perturbations.

I Block Reveals Separation of Timescales in Pyloric Rhythm Response to Temperature Changes in .

Motor systems operate over a range of frequencies and relative timing (phase). We studied the contribution of the hyperpolarization-activated inward current (I) to frequency and phase in the pyloric rhythm of the stomatogastric ganglion (STG) of the crab, as temperature was altered from 11°C to 21°C. Under control conditions, the frequency of the rhythm increased monotonically with temperature, while the phases of the pyloric dilator (PD), lateral pyloric (LP), and pyloric (PY) neurons remained constant.

Alterations in network robustness upon simultaneous temperature and pH perturbations.

Nervous systems have evolved to function consistently in the face of the normal environmental fluctuations experienced by animals. The stomatogastric nervous system (STNS) of the crab, , produces a motor output that has been studied for its remarkable robustness in response to single global perturbations. Changes in environments, however, are often complex and multifactorial.

A biophysical perspective on the resilience of neuronal excitability across timescales.

Neuronal membrane excitability must be resilient to perturbations that can take place over timescales from milliseconds to months (or even years in long-lived animals). A great deal of attention has been paid to classes of homeostatic mechanisms that contribute to long-term maintenance of neuronal excitability through processes that alter a key structural parameter: the number of ion channel proteins present at the neuronal membrane. However, less attention has been paid to the self-regulating 'automatic' mechanisms that contribute to neuronal resilience by virtue of the kinetic properties of ion channels themselves.

Gating of homeostatic regulation of intrinsic excitability produces cryptic long-term storage of prior perturbations.

Neurons and neuronal circuits must maintain their function throughout the life of the organism despite changing environments. Previous theoretical and experimental work suggests that neurons monitor their activity using intracellular calcium concentrations to regulate their intrinsic excitability. Models with multiple sensors can distinguish among different patterns of activity, but previous work using models with multiple sensors produced instabilities that lead the models' conductances to oscillate and then to grow without bound and diverge.

Risk Factors for Non-O157 Shiga Toxin-Producing Escherichia coli Infections, United States.

Shiga toxin-producing Escherichia coli (STEC) causes acute diarrheal illness. To determine risk factors for non-O157 STEC infection, we enrolled 939 patients and 2,464 healthy controls in a case-control study conducted in 10 US sites. The highest population-attributable fractions for domestically acquired infections were for eating lettuce (39%), tomatoes (21%), or at a fast-food restaurant (23%).

Sodium channel slow inactivation normalizes firing in axons with uneven conductance distributions.

The Na channels that are important for action potentials show rapid inactivation, a state in which they do not conduct, although the membrane potential remains depolarized. Rapid inactivation is a determinant of millisecond-scale phenomena, such as spike shape and refractory period. Na channels also inactivate orders of magnitude more slowly, and this slow inactivation has impacts on excitability over much longer timescales than those of a single spike or a single inter-spike interval.

Neuronal morphology enhances robustness to perturbations of channel densities.

Biological neurons show significant cell-to-cell variability but have the striking ability to maintain their key firing properties in the face of unpredictable perturbations and stochastic noise. Using a population of multi-compartment models consisting of soma, neurites, and axon for the lateral pyloric neuron in the crab stomatogastric ganglion, we explore how rebound bursting is preserved when the 14 channel conductances in each model are all randomly varied. The coupling between the axon and other compartments is critical for the ability of the axon to spike during bursts and consequently determines the set of successful solutions.

Elimination of PBB-153; findings from a cohort of Michigan adults.

Background: An industrial accident led to the widespread contamination of polybrominated biphenyl (PBB), a flame retardant, into the food system in Michigan in the 1970's. PBB continues to be detected in Michiganders' blood some forty years later. It is necessary to understand the elimination rate and half-life of PBB because it may provide clues on how to hasten the elimination of it from the human body.

The compliment sandwich.

What is the best way to ensure that scientific criticism is heard and understood?

Repeated applications of high potassium elicit long-term changes in a motor circuit from the crab, .

We examined the effects of altered extracellular potassium concentration on the output of the well-studied pyloric circuit in the crab, . Pyloric neurons initially become quiescent, then recover spiking and bursting activity in high potassium saline (2.5x[K]).

New insights from small rhythmic circuits.

Small rhythmic circuits, such as those found in invertebrates, have provided fundamental insights into how circuit dynamics depend on individual neuronal and synaptic properties. Degenerate circuits are those with different network parameters and similar behavior. New work on degenerate circuits and their modulation illustrates some of the rules that help maintain stable and robust circuit function despite environmental perturbations.