The Spine Lab: A Short-Duration, Fully-Remote Course-Based Undergraduate Research Experience

Course-based undergraduate research experiences (CUREs) are increasingly common approaches to provide students with authentic laboratory experiences. Typically, CUREs are semester-long, in-person experiences that can be financially and time prohibitive for some institutions, faculty, and students. Here, we developed a short-duration, fully-online CURE, the Spine Lab, to provide an opportunity for students to conduct original research. In this CURE, we focused on synaptic spines in the mammalian brain; synapses are the unit structure that functions in rapid information processing. The students worked together in pairs and as a class to analyze cortical neuron spine density and structural morphology changes between a mouse line with learning impairments (forebrain-specific β-catenin knockouts [β-cat cKOs]) and control (Ctl) littermates. The students showed their results in an online poster presentation. Their findings show that spine density is significantly reduced, while spine structural maturation is unaltered in the β-cat cKO. Defining pathophysiological changes caused by CTNNB1/β-catenin loss-of-function provides important insights relevant to human disorders caused by disruptive mutations in this gene. To assess the benefits of this CURE, students completed a pre- and post-test assessment including a content quiz, STEM identity survey, and a standardized CURE survey. Participation in the Spine Lab correlated with improved content and STEM identity scores, and decreased negative attitudes about science. Moreover, direct comparison to the CURE database reveals that the Spine Lab produces comparable benefits to traditional CUREs. This work as a whole suggests that short-duration, fully-online CUREs can provide benefit to students and could be an inclusive tool to improve student outcomes.

Uncovering Factors Influencing Instructors' Decision Process when Considering Implementation of a Course-Based Research Experience

Course-based undergraduate research experiences (CUREs) are an effective way to expose large numbers of students to authentic research, yet most laboratory courses still use traditional "cookbook" methods. While barriers to using CUREs have been captured postimplementation, little is known about the decision mindset before implementation or what features of CURE design may mitigate perceived barriers. Perception of an innovation (such as a CURE) influences the likelihood of its adoption, and diffusion of innovations theory posits that the decision to adopt is largely influenced by five perceived features of an innovation: relative advantage, compatibility, complexity, observability, and trialability. We conducted interviews with instructors considering using the Prevalence of Antibiotic Resistance in the Environment (PARE) project to assess their perceptions of CUREs and motivations for using PARE. Instructors viewed CUREs as having relative advantages over traditional methods; however, CUREs were also viewed as complex, with instructors citing multiple barriers. Instructors were motivated to use PARE because of its potential scientific impact and compatibility with their courses' structures and resources. Instructors perceived PARE to have few barriers to implementation compared with other CUREs. Designing CUREs that address common instructor barriers and drivers could increase the rate of diffusion of CUREs.

The PARE Project: A Short Course-Based Research Project for National Surveillance of Antibiotic-Resistant Microbes in Environmental Samples

Course-based research experiences (CREs) have been proposed as an inclusive model to expose all students, including those at institutions without a strong research infrastructure, to research at an early stage. Converting an entire semester-long course can be time consuming for instructors and expensive for institutions, so we have developed a short CRE that can be implemented in a variety of life science course types. The Prevalence of Antibiotic Resistance in the Environment (PARE) project uses common microbiology methods and equipment to engage students in nationwide surveillance of environmental soil samples to document the prevalence of antibiotic-resistant bacteria. The project has been implemented at institutions ranging from community colleges to doctoral-granting institutions in 30 states plus Puerto Rico. Programmatic feedback was obtained from instructors over three iterations, and revisions were made based on this feedback. Student learning was measured by pre/post assessment in a subset of institutions. Outcomes indicate that students made significant gains in the project learning goals. Journal of Microbiology & Biology Education.

Innate Fear-Induced Weight Regulation in the C57BL/6J Mouse

Regulation of body weight is an important strategy for small prey animals to avoid capture. Field and laboratory studies have shown that prey animals reduce body size when subjected to long-term predator stimuli. However, the causes of predator-induced weight regulation are highly variable and the underlying mechanisms remain unclear. Understanding this phenomenon is important for gaining a better understanding of how animals regulate body weight under ethologically relevant conditions and has implications for obesity. Here we expose inbred C57BL/6J mice to a fear-inducing odorant (2,4,5-trimethylthiazole; mT) to model predation-induced weight regulation. Eight week-old mice were put on a 45% high fat diet (HFD) or chow diet (5% fat) and exposed daily to mT, an equally aversive dose of butyric acid (BA), or a neutral control scent (almond). mT-exposed mice in both diet groups gained significantly less weight over a 6-week period than BA-exposed mice. This differential weight gain appears unlikely to be due to differences in food intake and activity level, or brown adipose thermogenesis between the mT and BA groups. However, following chronic mT exposure we find increases in ΔFosB protein, a marker for long-term neural plasticity, in the dorsomedial hypothalamus (DMH)-an area previously implicated in chronic stress and defensive responses, as well as weight regulation. This study establishes a simplified and robust laboratory model of predation-mediated weight regulation with inbred lab mice and fear-inducing odor, and suggests a likely, yet undetermined, metabolic adaptation as contributing to this response.

Thinking evolutionarily about obesity

Obesity, diabetes, and metabolic syndrome are growing worldwide health concerns, yet their causes are not fully understood. Research into the etiology of the obesity epidemic is highly influenced by our understanding of the evolutionary roots of metabolic control. For half a century, the thrifty gene hypothesis, which argues that obesity is an evolutionary adaptation for surviving periods of famine, has dominated the thinking on this topic. Obesity researchers are often not aware that there is, in fact, limited evidence to support the thrifty gene hypothesis and that alternative hypotheses have been suggested. This review presents evidence for and against the thrifty gene hypothesis and introduces readers to additional hypotheses for the evolutionary origins of the obesity epidemic. Because these alternate hypotheses imply significantly different strategies for research and clinical management of obesity, their consideration is critical to halting the spread of this epidemic.