bluuebunny/crossref_metadata_2025 huggingface dataset:
It Takes Two: Reflections on a Decade of Team Teaching
Authors: Beason‐Abmayr Beth , Caprette David
Published: May 2022

More often than not, a team‐taught course is divided among two or more faculty, such that each instructor is solely responsible for a subset of classes. We have co‐developed and team‐taught an introductory laboratory course in experimental biology targeted at first‐year undergraduate students and an interactive lecture course in animal physiology with both undergraduate and graduate students. Both of these courses were designed using evidence‐based pedagogical approaches to engage students in active learning. We combined our unique experiences, expertise, and creativity to design these courses and actively participated in co‐teaching throughout the semester. For example, one instructor took the lead in organizing the course structure and content and the other took the lead in developing laboratory and classroom activities. We also created assessments together or shared assessments that we had used in our other courses. Sharing the grading promoted a more objective evaluation of student work as well as helped us catch each other’s mistakes. Students greatly benefitted as they did not have to adjust to different styles of teaching and assessment midway through a course as would be the case with traditional team teaching. Having two instructors circulating among groups in the lab or in the classroom helped ensure that all teams received the attention they needed during the allotted time. Our students have given us much positive feedback, suggesting that the synergism resulting from sharing a course among more than one instructor has led to better instruction and a more successful learning environment than what they would have experienced in a course with a single instructor or with two or more instructors teaching back‐to‐back. Here we share some of our strategies for intentionally designing a team‐taught course and describe a few lessons we have learned along the way in over a decade of collaborative teaching. All protocols were approved by Rice University IRB (Protocol FY2017‐294).
Novel HDL mimicking targeted drug delivery system for the treatment of Ewing Sarcoma
Authors: Sabnis Nirupama A. , Raut Sangram , Nagarajan Bhavani , Lacko Andras , Lothstein Leonard , Fudala Rafal
Published: May 2022

Purpose

Since their discovery as antitumor agents, anthracycline drugs such as doxorubicin have remained mainstays as an important class of chemotherapy for the treatment of a wide range of cancers including pediatric malignancies like Ewing Sarcoma (EWS). Unfortunately, their usage is limited due to cumulative dose‐dependent cardiotoxicity. Targeted drug delivery could be an important option to circumvent this problem.

Experimental design

Our laboratory has developed a novel reconstituted HDL drug delivery system comprised of Myristic acid conjugated Apo AI mimicking 5A peptide (Myr5A). We used a hydrophobic derivative of doxorubicin, N‐Benzyladriamycin‐14‐valerate (AD198) to engineer formulations of Myr5A‐AD198. Physico‐chemical characterization including size, zeta potential and entrapment efficiency was determined. Cytotoxic effectiveness of this formulation was tested in Ewing Sarcoma cells A673 and Cardiomyocytes, H9c2 in 2D and 3D spheroid model using CCK‐8 assays. Using Myr5A based formulation‐containing BODIPY; mechanism of uptake of payload was demonstrated by imaging. In addition, we investigated Biodistribution and payload retention in EWS tumors in xenograft NOG mice with EWS tumor model.

Results

Formulation of the Myr5A‐AD198 was stable and non‐leaky with payload entrapment efficiency of 47.6 ± 3.2%. The nanoparticles were spherical with average size of 47 ± 12 nm as observed by transmission electron microscopy (TEM). Cytotoxicity assays demonstrated that IC50 values of Myr5A‐AD198 formulation was 2.8 ± 0.4 times more effective than free AD198 in EWS cells. On the other hand, 3 times more dose was required for Cardiomyocytes with Myr5A‐AD198 formulation as compared to free AD198. Blocking the Scavenger Receptor type B1 (SR‐B1) receptors, resulted in inhibition of the uptake of payload in Myr5A formulation. Subcutaneous injection of Myr5A‐IR 780 dye in xenograft NOG mice indicated the retention of payload for up to 72 hours in tumor.

Conclusion

These preclinical studies indicated a great translational potential of Myr5A‐AD198 formulation for the treatment of EWS patients due to its selective uptake mechanism and cardio‐protective effect. Longer retention of the drug in tumors as well as lower dose requirement compared to free drug gives an additional advantage. In future, the Myr5A based technology shows promise for personalized treatment options in EWS and other type of cancers as well.
Femoral neck anteversion in Xenarthra
Authors: Harper Christine M. , McAfee Robert K. , Sylvester Adam D. , Goldstein Deanna M. , Almonte Juan , Cooke Siobhán B.
Published: May 2022

Degree of femoral neck anteversion distinguishes extinct sloth genera from each other, particularly when analyzed in combination with femoral neck angle. These data have been previously analyzed using a comparative sample including only extant sloths, which limits functional interpretations. Here, we analyze both femoral neck anteversion and femoral neck angle broadly across Xenarthrans to reconstruct the locomotor behavior of extinct Caribbean sloths.

Femora of four extinct sloth genera (n=49; Acratocnus; Megalocnus; Neocnus; Parocnus) and nine extant Xenarthra genera (n=63; Bradypus; Choloepus; Cyclopes; Dasypus; Euphractus; Myrmecophaga; Pridontes; Tamandua; Tolypeutes) were surface scanned. Morphological axes representing the femoral neck, shaft, geometric axis of the femoral condyles (GA), and maximum dimension of the femoral shaft cross section at 30% of whole bone length were extracted. Degree of femoral neck anteversion was calculated relative to both the GA and cross section axes. Femoral neck angle was additionally calculated as the angle between the femoral neck and shaft axes. Non‐parametric MANOVAs with post hoc multiple comparison tests were used to test how the genera differed when the angle of femoral neck anteversion and femoral neck angle were analyzed in conjunction.

Parocnusdoes not significantly differ from any of the armadillo taxa when femoral neck angle is analyzed with either of the two anteversion angles (p>0.171 for all pairwise comparisons), supporting previous suggestions that Parocnuswas largely terrestrial. This finding also indicates that Parocnus may have had similar hindlimb biomechanics to armadillos, and possibly utilized digging behaviors. Megalocnusand Acratocnusdiffer significantly from all extant Xenarthrans (p<0.043 for all pairwise comparisons), but do not exhibit significantly different morphologies from each other (p=0.911). This suggests that the two genera may have utilized similar hip mechanics; however, their locomotor repertoires cannot be accommodated within the range of those exhibited by extant Xenarthrans.
Investigating the Effects of Premedical Experiences on Medical Student Neuroanatomy Self‐Efficacy
Authors: Bergden Jessica , Immekus Jason , Brueckner‐Collins Jennifer
Published: May 2022

One key issue in medical education is medical student fear of learning and applying neuroanatomy called neurophobia. In a previous study, we found a negative correlation between neurophobia and neuroanatomy self‐efficacy (one’s confidence in their ability to complete neuroanatomy tasks). Our findings suggest increasing neuroanatomy self‐efficacy may reduce one’s neurophobia. Additionally, the literature shows self‐efficacy improves academic achievement and clinical performance in medical school. It is unknown whether experiences before medical school may later influence medical student neuroanatomy self‐efficacy. This study aims to fill this literature gap by isolating which premedical experiences most significantly influence neuroanatomy self‐efficacy. We hypothesize medical students with premedical neuroanatomy‐specific experience will exhibit greater neuroanatomy self‐efficacy than students without this experience.

Instrumentation to measure neuroanatomy self‐efficacy and categorize premedical experiences was developed and administered to medical students (n=233). Premedical experiences were categorized as: neuroscience (NSC), neuroanatomy (NAC), neuroscience and neuroanatomy (NSAC), cadaveric gross anatomy (GR), or anatomy and physiology (AP). An analysis of variance with a Tukey’s post‐hoc test was performed to isolate which premedical experience(s) showed significant differences in neuroanatomy self‐efficacy compared to students with no previous experience. All statistical tests were performed at the p=0.05 level. IRB approval was obtained.

Data analysis showed indirect premedical neuroanatomy exposure as part of a premedical gross anatomy course (GR) resulted in greater neuroanatomy self‐efficacy (p=0.01, Cohen’s d= 0.50) compared to students with no previous experience. Interestingly, enrollment in a premedical molecular neuroscience (NSC) or neuroanatomy (NAC) course individually did not show an increase in neuroanatomy self‐efficacy. Only medical students with both premedical NSC and NAC experiences (NSAC) demonstrated higher neuroanatomy self‐efficacy than students with no premedical experience (p= 0.001, Cohen’s d= 0.52).

Premedical exposure to neuroanatomy as part of a gross anatomy course (GR) or enrollment in both premedical neuroanatomy andneuroscience courses (NSAC) appears to be associated with higher neuroanatomy self‐efficacy in medical students. Considering the decline in neurologists, and fewer medical students choosing neurology, these findings support youth STEM initiatives to provide increased access to both neuroscience and neuroanatomy experiences along with cadaveric gross anatomy.
Obesity‐Induced Lymphatic Valve Dysfunction
Authors: Castorena‐Gonzalez Jorge A. , Jablon Kelli L. , Akerstrom Victoria L.
Published: May 2022

A two‐way connection between obesity and lymphatic dysfunction has now been established. Clinical studies have demonstrated that obesity significantly increases the risk for developing secondary lymphedema. Using animal‐models, obesity has been linked to different aspects of lymphatic dysfunction including impaired contractility, flow‐mediated responses, and fluid transport, as well as increased permeability, and impaired dendritic cell migration among others. Dysfunction of lymphatic valves is a main form of lymphatic dysfunction, known to result in severe edematous phenotypes; however, the extent of lymphatic valve deficiency in secondary lymphedema, including obesity‐induced lymphedema, remains unknown. Therefore, the aim of the present study was to determine whether obesity resulted in lymphatic valve dysfunction. We quantitatively assessed and compared valve function in isolated popliteal and mesenteric collecting lymphatic vessels from control and diet‐induced obese mice. Feeding a western diet (N=7) for 14 weeks induced obesity, resulting in significant gain of body weight, i.e., 18.8±1.4 g, versus 9.7±0.7 g for mice fed a control diet (N=6). Obese mice displayed significantly higher non‐fasted blood glucose concentration when compared to controls. The function of lymphatic valves in popliteal lymphatics was not affected by diet‐induced obesity; however, obesity resulted in significant back‐leak of pressure in mesenteric lymphatic valves (0.1±0.1 versus 0.7±0.1 cmH2O for control (n=11) and obese (n=16) groups respectively). Dysfunctional, leaky valves from obese animals required significantly higher adverse pressure to trigger valve closure (i.e., 5.5±1.6 cmH2O, versus 0.9±0.3 cmH2O for controls, when upstream pressure was maintained at 0.5 cmH2O). In obese animals, valve dysfunction in mesenteric lymphatics was associated with structural and mechanical modifications including shortening of valve leaflets, enlargement of the lymphatic vasculature, and increased cross‐sectional distensibility. This is the first study that reports on quantitative assessment of lymphatic valve function in an animal model of obesity, and the first to link obesity with lymphatic valve dysfunction. Finally, utilizing a newly developed method for the isolation and culturing of primary lymphatic endothelial cells (LECs) from collecting vessels, our current and future experiments seek to assess and understand functional modifications to LECs induced by obesity in‐vitro. Specifically, using high‐speed confocal microscopy, mouse lines carrying genetically encoded Ca2+ indicators (i.e., Cdh5‐GCaMP8 and acta2‐RCaMP), and lymphatic cellular co‐cultures, we aim to determine whether obesity results in intracellular calcium dysregulation in LECs, and/or abnormal crosstalk between LECs and lymphatic muscle cells.
Trypanosoma cruzi dysregulates expression of piRNA that can regulate IL‐6 signaling in human cardiac fibroblasts during the early phase of infection
Authors: Rayford Kayla J. , Cooley Ayorinde , Arun Ashutosh , Rachakonda Girish , Villalta Fernando , Lima Maria F. , Pratap Siddarth , Nde Pius N.
Published: May 2022

Trypanosoma cruzi, the etiological agent of Chagas Disease, causes severe morbidity, mortality, and economic burden in endemic zones. Due to globalization, the disease is now present in all industrialized regions of the world. About 40% of infected individuals will develop cardiovascular, neurological, and/or gastrointestinal pathologies. Cardiomyopathies induced by chronic parasite infection include organ enlargement and fibrosis, accompanied by significant changes in the cellular expression of profibrotic factors and inflammatory molecules. Accumulating evidence suggests that the parasite induces alterations in host gene expression profiles to facilitate infection and pathogenesis. The role of regulatory gene expression machinery during T. cruzi infection remains to be elucidated. In this study, we aim to evaluate the expression of a class of small non‐coding RNA molecules, piwi‐interacting RNAs (piRNAs), during the early phase of T. cruzi infection in primary human cardiac fibroblasts (PHCF). Recent studies defined a role for STAT3 signaling in the onset of cardiac fibrosis in a Chagasic mouse model. Our bioinformatic analysis of parasite challenged PHCF identified significant modulation of piRNAs targeting IL‐6 signaling pathway components. To validate this, we performed qPCR of IL‐6, SOCS3, and piRNAs predicted to target IL‐6 and SOCS3. Furthermore, we evaluated protein expression for pSTAT3 (Y705) and SOCS3 in cell lysates and IL6 secretion in condition media of parasite challenged PHCF. We observed that the piRNAs expression negatively correlated with their target mRNA and protein expression of IL‐6. This suggests T. cruzi dysregulates the expression of piRNA that can regulate IL‐6 signaling during T. cruzi pathogenesis.
Impact of beta‐Hydroxy‐beta‐methylbutyrate plus Vitamin D3 Supplementation on Skeletal Muscle Size, Function and Quality in Sedentary and Resistance Exercise Trained Women
Authors: Elliehausen Christian J. , Fairfield William D. , Minton Dennis M. , Nichol Alex D. , Rathmacher John A. , Pitchford Lisa M. , Paluska Scott A. , Allen Jacob M. , Konopka Adam R.
Published: May 2022

The age‐related loss of skeletal muscle mass, quality, and strength can lead to the loss of independence later in life. Beta‐hydroxy‐beta‐methylbutyrate (HMB), a leucine metabolite, can increase skeletal muscle size and function. However, emerging evidence suggests HMB may be less effective at improving muscle function in people with insufficient Vitamin D3 levels (25‐hydroxy‐Vitamin D (25‐OH‐D) <30 ng/mL,) common in middle‐aged and older adults. Therefore, our current study tested the hypothesis that combining HMB (Calcium salt) with Vitamin D3 (HMB+D) would increase skeletal muscle size, quality and function in middle aged women (53±1 yrs, 26±1 kg/m2, n=43) randomized to sedentary control (SED) or progressive resistance exercise training (RT). In a placebo‐controlled, double‐blinded fashion, women were further randomized to placebo or HMB+D (3g of HMB + 2000IU of Vitamin D3). Study enrollment and recruitment occurred before and after COVID‐19 stay at home measures. In both RT and SED, HMB+D raised circulating levels of 25‐OH‐D after 8 (33±2 ng/mL) and 12 (35±2 ng/mL) weeks to reach sufficient Vitamin D3 levels. In SED, HMB+D prevented the loss of lean arm mass observed in the placebo group (0.07±0.06 vs ‐0.19±0.06 kg; P<0.05). HMB+D also increased thigh skeletal muscle (26±13 vs ‐5±8 cm3; P<0.05) and decreased intermuscular adipose tissue (IMAT) volume (‐20±11 vs 5±6 cm3; P<0.05) compared to placebo. However, 12‐weeks of HMB+D did not change skeletal muscle function. In the RT, 12‐weeks of HMB+D decreased IMAT compared to placebo (‐22±13 vs 6±4 cm3; P<0.05) but did not influence the increase in skeletal muscle mass or function. These data show that 12‐weeks of HMB+D supplementation consistently decreased thigh IMAT volume in both SED and RT. HMB+D in sedentary middle‐aged women was beneficial for skeletal muscle size but did not lead to improved muscle function or quality. Further, HMB+D did not influence the hypertrophic or functional improvements after resistance exercise training in middle‐aged women. HMB+D may be able to help combat the age‐related loss of skeletal muscle mass in sedentary women. These results lend support to conducting a larger study for a longer duration to validate these findings as well as explore additional populations who may also benefit from HMB+D.
The Structural Role of the Beta‐2 Adrenergic Receptor Function for the Pharmacological Treatment of Cardiopulmonary Diseases
Authors: Link Tina , Kona Abhinav , Dunaway Katherine , Singh Siddhant , Stark Kaylan , Thomas‐Wilkinson Phillipa
Published: May 2022

As a part of the group of Beta‐Adrenergic receptors (B1, B2, B3), the Beta‐2 Adrenergic receptor is a transmembrane glycoprotein that is principally responsible for the mediation of physiological function over the pulmonary and cardiovascular systems through the binding to the catecholamine, adrenaline (epinephrine). Residing in a larger superfamily of hormone‐activated G‐Protein‐Coupled‐Receptors (GPCR), the B2AR adrenoceptor is composed of 3 extracellular and 5 intracellular alpha helices that are coupled with the heterotrimeric G protein, Gs. When the alpha subunit of Gs is bound to GDP, the B2AR adrenoceptor undergoes structural changes upon activation to transmit the communicative signals to the adenylyl cyclase via the stimulatory G‐protein. Consequently, the B2AR receptor resides in two structural conformations: the active and inactive state, dependent on the binding of the GDP to Gs. The shift in equilibrium between each state in proportion to the strength of the binding agonist has brought about new therapeutic research proposing the in silico screening of new B2AR ligands to improve affinity and selectivity profiles of adrenergic agonists. When bound to a full agonist, B2AR exhibits an 11‐Armstrong (A) protrusion of TM6 and inward folding of TM7 and TM3 to transform into a highly unstable arrangement that cannot be adequately established by the potential binding of a stronger agonist alone. The differences inside the ligand‐binding pocket are more subtle but exemplify the weakening of the polar interactions between the amino acids Asn293, Ser203, and Ser207. Once B2AR is activated by any partial or positive agonist, the detached stimulatory G‐protein catalyzes the activity of adenylyl cyclase. In turn, the intracellular cyclic adenosine monophosphate (cAMP) content is elevated significantly. cAMP initiates simultaneous pathways that aid in the release of constricted airways of bronchospastic patients. The pathways induced by the B2AR receptor therapeutically target muscle cell contraction, uterine relaxation, and premature labor within tocolytic drug candidates. Alternatively, B2AR functioning can be restrained by antagonists to inhibit basal, agonist‐independent activity that can be fatally detrimental, such as the continual production of glucose from glycogenolysis. The methodological advances to discover ligands that can function as inverse agonists through the crystallogenesis of B2AR proves to create promising drug treatments for cardiopulmonary diseases involved with muscle contraction. The Walton High School MSOE Center for Biomolecular Modeling SMART Team has designed a 3‐D model of B2AR to further investigate the structure of beta‐2‐adrenergic receptor function relative to adrenaline for pharmacological drug discovery.
Cardiomyocyte‐specific Adhesion G Protein‐Coupled Receptor F5 mediates cardiac homeostasis and contractility
Authors: Einspahr Jeanette , Patwa Viren , Roy Rajika , Tilley Douglas G.
Published: May 2022

G‐protein coupled receptors (GPCRs) serve as pharmacological targets for a third of all currently prescribed drugs, including gold‐standard heart failure (HF) therapeutics. However, the second largest class of GPCRs, adhesion GPCRs (aGPCRs), have yet to be established as clinical targets, representing an area of highly unexplored druggable potential. RNA‐sequencing analysis of left ventricle (LV) tissue isolated from healthy hearts of adult mice identified ADGRF5 as the most highly expressed aGPCR, which was validated in isolated adult mouse cardiomyocytes (AMCM) and shown to increase in response to transaortic constriction (TAC) surgery. To determine the impact of ADGRF5 on cardiac parameters normally or during HF, we generated constitutive cardiomyocyte‐specific (αMHC‐Cre‐driven) ADGRF5 knockout mice (CM‐ADGRF5‐KO), which displayed normal cardiac structure and function at 12 weeks of age, as assessed via echocardiography, gravimetrics and immunohistochemistry. However, over time CM‐ADGRF5‐KO mice developed worsened cardiac function and remodeling with increased mortality, even in the absence of pathologic insult, suggesting ADGRF5 provides a homeostatic regulatory function in the heart. Further, we observed that CM‐ADGRF5‐KO mice experienced an accelerated decrease in cardiac function following transaortic constriction injury (TAC) surgery with greater pathologic remodeling. To identify the mechanistic underpinnings which underlie these phenotypes, we have identified an increase in NFAT‐luciferase activity following stimulation of CM‐ADGRF5 using a synthetic ligand, GAP10, to activate CM‐ADGRF5, in vitro. This suggests that the receptor couples to Gαq signaling to mediate its effects, an intriguing finding which requires further investigation. In all, these results suggest that ADGRF5 plays an integral role in the maintenance of cardiac health normally and during the development of HF.
Proteasome Localization is Regulated Through Mitochondrial Respiration and Kinase Signaling
Authors: Waite Kenrick A. , Roelofs Jeroen
Published: May 2022

In most organisms, proteasomes are enriched in cell nuclei under optimal physiological conditions, indicating an important need for protein degradation in this organelle. However, stress conditions can result in proteasome nuclear export, possibly reflecting changes in demand for protein degradation. To understand this adaptive response, it is crucial to know when and how proteasome localization and activity are altered upon changing cellular needs. In yeast, carbon starvation triggers a reversible re‐localization of proteasomes to cytosolic granules known as proteasome storage granules (PSGs). These PSGs behave like liquid‐liquid phase separated structures and highlight a link between cellular metabolism and proteasome localization. We hypothesized that mitochondrial respiration is important in this process. To test this, we manipulated the glycolytic and respiratory activity in yeast using different carbon sources as well as chemical inhibitors of mitochondrial function and monitored proteasome localization by fluorescent microscopy. Growing cells in carbon sources that necessitate respiration prior to starvation, caused a strong reduction in proteasome storage granule formation upon carbon starvation. This suggests that the mitochondrial activity of cells is a determining factor in proteasome localization. Consistent with this, upon chemical inhibition of mitochondrial function, we observed proteasomes re‐localize to cytosolic granules independent of starvation stress. Interestingly, the stress response kinase Snf1, which is not required for proteasome re‐localization upon carbon starvation, was required for proteasome re‐localization following mitochondrial inhibition. In addition, MAP kinases of the cell wall integrity cascade were required for proteasome granule formation, specifically following respiratory but not glycolytic growth, upon carbon starvation or mitochondrial inhibition. In all, our data point to a model where mitochondria regulate proteasome localization via kinases that sense the cells metabolic state.
Cannabinoid Receptor‐Mediated Synaptic Signaling and Neural Plasticity in Central Olfactory Neurons
Authors: Heinbockel Thomas , Wang Ze‐Jun
Published: May 2022

Our studies aim to understand integrative and computational mechanisms that allow main olfactory bulb neurons to respond to afferent input and synaptic or feedback signals. The endocannabinoid (eCB) signaling system has been functionally implicated in many brain regions but our understanding of the role of cannabinoid receptor type 1 (CB1R) in olfactory processing remains limited. Endocannabinoids are known to mediate retrograde signaling at synapses in several brain regions through a form of short‐term neural plasticity. Endocannabinoids are released from depolarized principal neurons and rapidly diffuse to presynaptic inhibitory interneurons to transiently reduce presynaptic firing and neurotransmitter (GABA) release (Depolarization‐Induced Suppression of Inhibition, DSI).

We study the function of the endocannabinoid system in regulating neural activity at synapses in the main olfactory bulb, the first central relay station in the brain for the processing of olfactory information coming from the nose. Our experimental approach uses electrophysiological recording techniques, specifically whole cell patch‐clamp recordings. Previously, using anatomical approaches, we showed that CB1R is present in periglomerular processes of a GAD65‐positive population of interneurons but not in mitral cells, key output neurons. We detected eCBs in the mouse main olfactory bulb as well as the expression of CB1R and other genes associated with the cannabinoid signaling system.

Output neurons such as mitral cells and tufted cells in the olfactory bulb are computational elements in brain circuits that integrate incoming signals with membrane properties to generate behaviorally relevant synaptic output. Our data support the notion that retrograde signaling is present in neural circuits involving mitral and tufted cells. Mitral and tufted cells release endocannabinoids and, through retrograde signaling, inhibit presynaptic interneurons such as periglomerular cells, which controls the GABA release of these presynaptic neurons. This, in turn, allows mitral and tufted cells to temporarily regulate their synaptic input and relieve them from synaptic inhibition. Endocannabinoids function as retrograde messengers to regulate neural signaling and mediate plasticity at olfactory bulb synapses with potential effects on olfactory threshold and behavior.
Estrogen‐mediated signaling mechanisms regulate voluntary running behavior in rats
Authors: Mathis Victoria , Points Lauren , Pope Brock , Lee Chia‐Ming , Li Yaru , Winter Lori , Clayton Sarah , Yuan Li‐Lian
Published: May 2022

Despite the myriad social and health benefits of exercise, humans display heterogeneous levels of participation. Significant progress has been made in identifying molecular events, systems, and mechanisms that support exercise’s beneficial effects, but it is not clear yet what regulates exercise behavior itself or serves to maintain prolonged chronic exercise behavior.

The human heterogeneity in voluntary exercise can be recapitulated in a rodent model of wheel running, a behavior with high rewarding properties. While rats given continuous access to running wheels all began with low running activity, a 3‐week training program dramatically increased running activity and uncovered a wide range of individual differences in running behavior. In addition, we have identified intriguing sex differences in this model. Compared to age‐matched males, female rats exhibited significantly higher levels of average daily running. When assessing individual female rats’ running behavior, we also observed a repetitive peak‐valley pattern of running activity, with peaks coinciding with the proestrus stage (highest estrogen level) in the rat estrous cycle. Bilateral ovariectomy (OVX) not only lowered their overall running activity, but also completely eliminated cyclical variations. Furthermore, low dose estrogen replacement via osmotic mini‐pumps in an OVX background restored running activity to pre‐OVX levels, and acute estradiol injections were able to replicate running peaks. Collectively, those results suggest estrogen exerts strong regulation of female running activity. By taking individual and sex differences into consideration in the experimental design, we anticipate our subsequent biochemical assays will identify signaling molecules and pathways involved in running activity that is driven by a surge of estradiol.
Energy Balance and Muscular Power Alterations Following Repeated 4‐Hour Exercise Dives
Authors: Considine Elizabeth G. , Simmons Erin E. , Bergeron Elizabeth R. , Klemp Alex O.
Published: May 2022

Divers often perform repeated dives with taxing activity using various underwater breathing apparatuses (UBA), which may increase total energy expenditure (TEE) and alter energy balance (EB) and physical ability. However, data is lacking regarding metabolic and muscular responses to repeated diving. We tested the hypotheses that repeated diving induces negative EB and decreases muscular force, but these decrements would not be affected by UBA. 16 military divers participated in 3 4‐hr dives (31 ± 2 °C) at 1.3 ata, with 20‐hr surface intervals, while wearing a MK25 (n=8, age: 33.8 ± 4.4 yr) UBA with 100% oxygen or MK20 (n=8, age: 36.0 ± 4.7 yr) with air. During dives, subjects alternated 30 min rest and cycling exercise at 60% HRmax. EB was calculated as TEE – energy intake (EI). TEE was measured via doubly labeled water (DLW; 4‐8 atom % 2H2O and 8‐12 atom % 18O). Urine samples were taken before each dive, and for 4 days after diving to assess differences in EB diving and non‐diving (control) days. EI was assessed via food logs. EB, TEE, and EI were normalized to body weight. Before and after each dive, peak force (PF) and rate of power development (RPD) were measured on a force plate during 3 countermovement jumps (3J) and while hopping in place for 10 sec (Hop). EB and muscular power were analyzed with mixed model ANOVAs (UBA: MK25 vs MK20, Diving: Dive Day (DD) vs Control Day (CD), Dive: Pre vs Post Dive, Repeated Diving: Dive 1, 2, 3). There was no effect of UBA on EB during dive days (MK25: ‐12.8 ± 8.9 kcal/kg; MK20: ‐8.4 ± 6.2 kcal/kg); but, EB did increase during diving (p < 0.01, DD: ‐13.0 ± 7.6 kcal/kg; CD: ‐6.7 ± 10.4 kcal/kg). There was no effect of UBA on TEE (p = 0.16, MK25: 37.6 ± 5.6 kcal/kg, MK20: 42.3 ± 2.5 kcal/kg) during dive days; but, TEE (p < 0.01) increased on dive days compared to control (DD: 39.6 ± 5.2 kcal/kg; CD: 31.2 ± 7.0 kcal/kg). There was no effect of UBA or diving on EI. 3J‐RPD (p < 0.01) and Hop‐RPD increased (p < 0.01) with repeated diving (3J‐RPD – D1: 11.7 ± 3.9 kW/s vs. D2: 13.0 ± 4.0 kW/s, p > 0.05; D1 vs. D3: 13.7 ± 3.9 kW/s, p < 0.01; D2 vs. D3, p > 0.05; Hop‐RPD – D1: 37.4 ± 21.6 kW/s vs. D2: 46.1 ± 29.0 kW/s, p = 0.02; D1 vs. D3: 49.9 ± 27.1 kW/s, p < 0.01; D2 vs. D3, p > 0.05). There was a group effect for 3J‐PF (p = 0.02) and 3J‐RPD (p < 0.01) with higher PF (MK25: 1948 ± 205 N; MK20: 1655 ± 223 N) and RPD (MK25: 15.2 ± 3.5 kW/s; MK20: 10.4 ± 2.9 kW/s) in MK25, but no other effects. Repeated 4‐hr exercise dives induce negative EB due to higher TEE, independent of UBA. RPD increased after repeated diving; however, further research is needed to determine mechanisms.
Analysis of the Hydrophobic Cleft of Perilipins 3 and 5
Authors: Dean Kaitlin M. , Tansey John T.
Published: May 2022

Obesity, type II diabetes mellitus, and non‐alcoholic fatty liver disease are all diseases associated with dysfunction of lipid metabolism or lipid mobilization – the breakdown of lipids into free fatty acids and glycerol. Because of this, research done on topics related to lipid metabolism provides potentially valuable insight into disease pathogenesis. Neutral lipids in the cell are stored in lipid storage droplets coated with at least one of the perilipin family of proteins, essential regulators of lipase function. Previous work by other laboratories has indicated that the carboxy terminus of perilipin 3 folds into a boot‐like structure consisting of a four‐helix bundle capped by a mixed α‐β domain. At the interface of the four‐helix bundle and the mixed α‐β domain is a hydrophobic cleft of unknown function. The genomic organization, nucleotide sequence, and amino acid sequence of perilipins 3 and 5 are highly conserved, particularly in the region that contains this hydrophobic cleft. Threading the sequence of perilipin 5 onto perilipin 3 using both RAPTOR X and PHYRE 2 produces a similar structure that also includes conservation of the pocket of interest. To study interactions of the hydrophobic pocket, models of the proteins were docked in silico to a series of small organic biological molecules using the GOLD software package from Cambridge Crystallographic Database. Mono and bicyclic systems were docked and yielded CHEMPLP scores ranging from approximately 25 to 45. Docking results were visualized and verified and fits compared using the molecular visualization software HERMES. Examination of current results informed future decisions of which candidate molecules to attempt to dock. The increasing CHEMPLP scores for the molecules examined, and their fits into the pocket seen in Hermes, indicate that a small molecule may bind to this pocket, potentially impacting the biological function of this class of proteins. Additionally, this work may provide a means for development of small molecules which could be used as possible pharmacological interventions for the treatment of lipid storage disorders.
Cephalic Ganglia Transcriptomics of the American Cockroach (Periplaneta americana) Yield Insights into Signaling Infrastructure and Metabolism of the Central Nervous System
Authors: Levy Ilana , Sanchez Benjamin , Arvidson Ryan
Published: May 2022

The American cockroach Periplaneta americana has been a model organism for biochemical and physiological study for almost a century, however, its use does not benefit from the genetic tools found in key model species such as Drosophila. To facilitate the use of the cockroach as a model system in neuroscience, and to serve as a foundation for functional and translational experimentation, a transcriptome of the cephalic ganglia was generated and annotated. The transcriptome of the cerebral and gnathic ganglia of the cockroach was assembled and differential expression profiles between these ganglia were generated. The transcriptome assembly yielded >400k transcripts, with >40k putative coding sequences. Gene ontology and protein domain searches indicate the cerebral and gnathal ganglia have distinct genetic expression profiles, while on the other hand none of the >100 identified GPCRs were differentially expressed. The developmental Toll signaling pathway appears to be active in the adult CNS, which may suggest a separate role for this pathway besides innate immune activation or embryonic development. The catabolic glycolytic and citric acid cycle enzymes are well represented in both ganglia, but key enzymes are more highly expressed in the gnathal ganglia. Both ganglia express gluconeogenic and trehaloneogenic enzymes suggesting a larger role of the CNS in regulating hemolymph‐sugar homeostasis than previously appreciated. Several homologs of proteins involved in synaptic plasticity and neurodegenerative diseases are also present. The annotation and quantification of the cephalic ganglia transcriptome reveal both canonical and novel pathways in signaling and metabolism in an adult insect and lay a foundation for future functional and genetic analysis. Additionally, the presence of homologs whose mutations are known to be critical in human nervous systems diseases may allow for adaptation from Drosophilaand mouse models, opening new avenues for experimentation into disease processes and pharmacology. These results shed light on the signaling and metabolic pathways of the cockroach brain and may expand of the role of the cockroach as a model system in neuroscience research.
Topographical Mapping of Catecholaminergic Axon Distribution and Morphology in the Flat‐Mounts of the Mouse Heart
Authors: Bizanti Ariege , Zhang Yuanyuan , Bendowski Kohlton , Chen Jin , Heal Maci , Osanlouy Mahyar , Tappan Susan , Hunter Peter J. , Cheng Zixi J.
Published: May 2022

The sympathetic nervous system plays a crucial role in the control of heart functions. However, the distribution and morphology of sympathetic postganglionic innervation of the heart has not been well elucidated, which has significantly impeded the understanding of the sympathetic neuroanatomical organization and control of the heart. Our goal is to provide a map of the topographical innervation of sympathetic postganglionic neurons in the whole heart of mice. In this study, we used Tyrosine hydroxylase (TH) as a marker for sympathetic axons and applied a combination of state‐of‐the‐art techniques, including confocal microscopy, Zeiss Imager microscopy, flat‐mount tissue processing and immunohistochemistry, Neurolucida 360 Tracing and integration of the tracing data onto a 3D heart scaffold. We found that 1) Multiple large extrinsic TH‐IR nerve bundles entered the heart and branched out into smaller axons which covered the whole left and right atria and ventricles, 2) These TH‐IR bundles branched out into smaller axon bundles and ramified into individual axons covering the whole left and right atria and ventricles. 3) The TH‐IR axons formed an extensive neural network in the epicardium and axons formed varicose synaptic endings within the cardiac muscle. 4) TH‐IR axons and terminals were densest in the sinoatrial (SA) and atrioventricular (AV) node regions. 5) TH‐IR axons innervated blood vessels and fat cells. 6) Many principal neurons in intrinsic cardiac ganglia and small intensely fluorescent (SIF) cells were TH‐IR. 7) However, TH‐IR axons do not appear to innervate any cardiac principal neurons and SIF cells. 8) TH‐IR axon innervation will be integrated into a 3D scaffold. Our work will provide a comprehensive topographical map of the catecholaminergic efferent axon distribution, innervation, and morphology of the whole heart at single cell/axon/synapse scale that will be used to create a cardiac sympathetic‐brain atlas. It will also provide an anatomical reference to evaluate the altered sympathetic cardiac control in pathological conditions. The first two authors contributed equally to this work.
Ciprofloxacin May Cause an Anxiety‐like Phenotype in a Rodent Model of Fluoroquinolone Associated Disability
Authors: Getaneh Bitseat , Kerler Jacqueline , Bove Cecilia
Published: May 2022

Fluoroquinolones (FQ) are one of the most commonly prescribed antibiotics used to treat several infections including urinary tract infections, bacterial bronchitis, and bacterial gastroenteritis. However, the FDA has restricted their use to life‐threatening infections only, or for infections for which other antibiotics do not show therapeutic efficacy. The most frequent side‐effects reported include common gastrointestinal reactions (nausea, vomiting) and severe side effects, including Central Nervous System adverse reactions such as dizziness, insomnia, and severe mood disorders. For this reason, the existence of Fluoroquinolones‐Associated Disability has been proposed as the constellation of disabling side effects that may arise following administration of these antibiotics. Other preliminary data from our laboratory shows that administration of 20 mg/kg of ciprofloxacin (CPX), one of the most commonly prescribed FQs, permanently accelerates gastrointestinal transit. The goal of this study is to test whether the same dosage of CPX affects anxiety‐ and depression‐like behaviors in rats, and whether or not these behavioral changes are correlated to the observed gastrointestinal dysfunction. 3 males and 3 female rats received 20mg/kg of CPX through oral gavage once a day for 14 consecutive days. The Elevated plus‐maze test (EPM) and Sucrose Preference Test (SPT) were administered before the beginning of the treatment with CPX (baseline) and once weekly for a total of 4 weeks. At this dose, CPX did not affect the rats' preference for 1% sucrose water vs regular water in the SPT test. However, while we did not observe any differences in the time spent in the open or closed arm, nor in the number of entries in either arms, the EPM test showed that there was a significant difference in the time spent in the neutral zone for male CPX treated rats at 7, 21, and 28 testing days compared to baseline. This data shows that 20 mg/kg of CPX do not induce anhedonia, a measure of depression‐like behavior, but can induce an anxious phenotype in male rats only, which does not appear to be associated with the observed acceleration of gastrointestinal transit. Future experiments will determine whether this behavior is associated with an increase in anxiety, as observed in numerous clinical cases, or if it is caused by either a decrease in motor performance or cognitive abilities following CPX administration.
Effects of Physical Activity During Pregnancy on Maternal and Fetal Health Outcomes
Authors: Abuoqab Lema O.
Published: May 2022

Introduction

Physical activity during pregnancy and its effects on fetal fat accrual and lipids has not been deeply explored. The purpose of this study was to further investigate how fitness during pregnancy relates to neonatal adiposity.

Methods

30 mothers were surveyed using the Pregnancy Physical Activity Questionnaire (PPAQ) at early pregnancy (EP; 12‐16 weeks), and of these 27 completed the study at late pregnancy (LP; 34‐36 weeks). Mothers were analyzed by sedentary, light, moderate, and vigorous activities, involvement in caregiving, occupations, and exercise. Mothers’ body composition (% fat and fat free mass) assessed by air densitometry (BOD POD), and BMI, were tracked throughout pregnancy. Infant adiposity (% fat via air densitometry/PEA POD) was measured within 48 hours of birth. Umbilical venous (UV) lipid levels were measured in the clinical pathology lab by standard methodology. Associations between maternal physical activity and infant outcomes were analyzed using non‐parametric Spearman correlation.

Results

EP fitness scores were positively correlated with parity (P=0.0047). EP overall scores were positively correlated with higher first trimester maternal BMI (P=0.0205). EP fitness scores were negatively correlated with infant % fat free mass (P=0.0407), and showed no significant correlation with any other infant factors post birth. LP PPAQ scores were negatively correlated with infant % fat free mass (P=0.0180); and positively correlated to infant % fat (P=0.0230). LP fitness scores, unlike EP, were negatively correlated with UV LDL, non‐HDL, and cholesterol readings (P=0.0172, P=0.0347, and P=0.0087, respectively). Infants of mothers who decreased in fitness between EP and LP had trends of higher levels of UV HDL, LDL, and non‐LDL compared to infants of mothers who had increased fitness.

Conclusion

Unexpectedly, higher maternal fitness levels correlated with higher maternal BMI and infant adiposity, potentially due to skewness in the PPAQ towards questions involving household or caregiving activity. Indeed, higher fitness scores were associated with parity. As postpartum weight retention is a risk factor for obesity, this may also explain the positive correlation between fitness and infant adiposity, potentially mediated by high maternal BMI. As the change in maternal fitness from EP to LP is correlated with UV lipids, our findings suggest that modifications of maternal physical activity during pregnancy may impact lipid transfer in utero. Future studies should investigate the effect of maternal fitness on placental function.
Impact of Acute Hyperbaric Oxygen Treatment on Phrenic Motor Output in Adult Male Rats
Authors: Thakre Prajwal P. , DeLucia Claire M. , Sunshine Michael D. , Fuller David D.
Published: May 2022

Hyperbaric oxygen (HBO) therapy involves exposure to 100% oxygen delivered above one atmosphere absolute (ATA), typically for ≤1 hour. HBO therapy is commonly used for promoting wound healing and treating decompression sickness. HBO treatment radically increases arterial oxygen content and can stimulate production of anti‐oxidants and suppress inflammation. These and other HBO‐induced responses could potentially impact the neural regulation of breathing. Here we investigated if exposure to HBO (100% O2, 2 ATA, 1 hr) impacts baseline phrenic motor output or the ability to express phrenic long term facilitation induced by acute intermittent hypoxia (AIH). Adult male Sprague‐Dawley rats were treated with HBO (n=8) or sham treatment (n=7, room air, 1 ATA), and then immediately urethane‐anesthetized and mechanically ventilated. Rats were vagotomized and phrenic nerve output was recorded using a suction electrode. On average, 86±23 min elapsed from the end to HBO treatment to the initiation of phrenic recordings. After establishing the CO2 apneic and recruitment thresholds, a stable baseline was maintained at 2 mmHg above of recruitment threshold for 15‐20 min. Rats were then exposed to AIH which consisted of three 5‐min episodes of moderate hypoxia (arterial partial pressure of O2, PaO2, approximately 45 mmHg) separated by 5‐min intervals of baseline O2conditions. Arterial samples were drawn at baseline, during hypoxia and every 20 min following AIH for blood‐gas analysis. Phrenic activity was recorded for 60 min after AIH. An unpaired two‐tailed t‐test was applied to compare baseline (BL) parameters between groups. Analysis of long term facilitation of phrenic burst amplitude after AIH (expressed as %BL) was done using two‐way repeated measures ANOVA. The HBO treatment did not affect baseline parameters including phrenic burst amplitude (p=0.34), burst frequency (p=0.48), mean arterial blood pressure (p=0.66), PaO2 (p=0.86) or PaCO2 (p=0.27). Phrenic LTF tended to be greater in the HBO group (burst amplitude 81±50 %BL at 60 min) as compared to control (43±9 %BL at 60 min). However, this difference was not statistically significant (treatment effect, P=0.16). Our preliminary conclusion is that a single session of HBO at 2 ATA for 1 hour has no detectable impact on baseline phrenic motor output recorded approximately 90 minutes after end of the HBO treatment. Additional experiments are needed before drawing a firm conclusion regarding the impact of HBO on phrenic long‐term facilitation.