bluuebunny/crossref_metadata_2025 huggingface dataset:
The Norepinephrine‐dependent ‘Postinspiratory Complex’ is NOT an Autonomous Generator of the Postinspiratory Rhythm
Authors: Poon Chi‐Sang , Song Gang
Published: November 2023

Previous studies have identified a defined population of postinspiratory (post‐I) driver neurons in pontine Kölliker‐Fuse nucleus which send an excitatory input to post‐I interneurons and motoneurons in medulla1. In contrast, a recent report2 suggests that a group of norepinephrine (NE)‐dependent cholinergic neurons localized within a medullary area dubbed the ‘post‐I complex’ (PiCo) may produce post‐I bursts as well as ectopic bursts that outpace the inspiratory rhythm in vitro. Because the inspiratory and post‐I rhythms are always phase‐locked in vivo, we tested whether the spontaneous post‐I rhythm was dependent on NE by injecting i.v. in rats an α1‐adrenergic receptor antagonist known to block the excitatory effect of NE on respiratory‐related neurons. Remarkably, systemic α1‐adrenergic blockade resulted in a significant decrease of arterial blood pressure but postinspiration at rest and during hypoxic chemostimulation persisted. Next, we suppressed NE facilitation of respiratory‐related neurons by injecting i.v. an α2‐adrenergic receptor agonist known to block the release of NE from pontine noradrenergic neurons. Systemic α2‐adrenergic blockade resulted in a significant decrease of hypoglossal nerve activity but postinspiration at rest and during hypoxic chemostimulation again persisted, indeed with a significant prolongation of the post‐I period. These data strongly suggest that NE‐facilitated PiCo neurons are not necessary for generating post‐I activity, although other NE‐inhibited neurocircuits could play a role. This is in contrast to the reported suppression of vagal post‐I activity after bilateral injections of the peptide somatostatin or the μ‐opioid receptor agonist DAMGO into the mouse PiCo in vivo2. This discrepancy may be attributed to the excessively large volume of injection (reportedly 250 nl) in mice2—which would inevitably invade the neighboring Bötzinger complex where similar injections at a much smaller volume (20–50 nl) has been shown sufficient to produce similar effects in rats. Interestingly, post‐I PiCo neurons are phenotypically akin to post‐I laryngeal motoneurons which (1) are cholinergic; (2) receive catecholamine inputs; (3) receive simultaneous excitatory and GABAA receptor‐mediated inhibitory inputs during inspiration followed by a postinhibitory rebound postinspiration; (4) mediate the laryngeal adductor reflex resetting of inspiratory rhythm; (5) do not generate the post‐I rhythm. The NE‐dependent ectopic PiCo neuronal bursts in vitro are reminiscent of fictive rhythmic bursting in motoneurons and are non‐autonomous and nonphysiologic. Finally, available functional and histologic data do not support the notion that cholinergic PiCo neurons are also glutamatergic.

Support or Funding Information

HL093225, HL127258 and NS094178
Eupnea, Tachypnea, and Autoresuscitation in a Closed‐Loop Respiratory Control Model
Authors: Diekman Casey O , Wilson Christopher G , Thomas Peter J
Published: November 2023

The mechanisms underlying oscillations in a central pattern generator (CPG) may differ fundamentally in the intact organism versus an isolated CPG preparation. We investigate this aspect of rhythmogenesis in a computational model of closed‐loop respiratory control, incorporating minimal models of the brainstem CPG, lung mechanics, oxygen handling, metabolism, and chemosensation. We analyze the model behavior using fast/slow dynamical systems analysis and open‐loop/closed‐loop control analysis. We show that eupnea‐like bursting oscillations arise from a distinct mechanism in the intact (closed loop) versus isolated (open loop) systems. The closed‐loop model exhibits bistability between eupnea‐like bursting and tachypnea‐like tonic spiking, and we demonstrate that imposed bouts of hypoxia can induce a dramatic transition from eupnea to tachypnea. For moderate bouts of hypoxia, the endogenous properties of the ionic conductances in the Butera‐Rinzel‐Smith CPG model can lead to spontaneous autoresuscitation and recovery to eupnea. We also find that chemosensory feedback gives the closed‐loop control system greater robustness to changes in metabolic demand than the open‐loop control system.

Support or Funding Information

This work was partially supported by grants from the National Science Foundation (DMS 1413770, 1412877, and 1555237) and by an intramural grant from Loma Linda University.
Effects of Inhaled Erythropoietin on Canine Post‐pneumonectomy Compensatory Lung Growth
Authors: Dane Dan Merrill , Yilmaz Cuneyt , Gyawali Dipendra , Ravikumar Priya , Estrera Aaron S , Menon Jyothi , Nguyen Kytai , Tustison Nicholas J , Gee James C , Hsia Connie C.W.
Published: November 2023

Paracrine erythropoietin (Epo) signaling via its receptor (EpoR) recruits endothelial progenitor cells and promotes angiogenesis. Epo‐EpoR axis is upregulated during canine post‐pneumonectomy (PNX) compensatory lung growth (CLG). To determine whether exogenous Epo augments endogenous CLG, adult male canines (age 1 year, 25.1± 3.4 kg, mean±SD) underwent right PNX and received either recombinant human Epo (100 units/kg) encapsulated within poly‐lactic‐co‐glycolic acid (PLGA) nanoparticles (NPs, 0.5 mg/kg) or empty NPs (n=4 animals each), suspended in phosphate buffered saline, nebulized (4μm droplets) and delivered via a previously constructed permanent tracheal stoma. Treatment was repeated weekly for 14 weeks. High resolution CT (HRCT) was performed at two transpulmonary pressures (10 and 30 cmH2O) and lung function was measured using established techniques under anesthesia pre‐PNX and post‐PNX following treatment. HRCT images were analyzed to quantify lobar air and tissue volumes, fractional tissue volume (FTV), parenchymal strain magnitude along 3D coordinate axes, principal strains and shear distortion using established deformation analysis. The remaining lobes were fixed at 25 cm H2O airway pressure for morphometric analysis.

Compared to control treatment, Epo delivery increased serum Epo concentration by 6–13% (p<0.05) without increasing systemic hematocrit. Epo delivery selectively increased the magnitude and reduced the coefficient of variation of in vivo FTV (10–20%, p<0.05) of the remaining lobes without altering lobar air and tissue volumes, principal strains or shear distortion measured by HRCT. Epo treatment increased the prevalence of alveolar double capillary profiles measured at postmortem by 12–28% (p=0.06), indicating mild enhancement of new capillary formation. However, resting lung diffusing capacity (DLCO), pulmonary blood flow, lung compliance, and postmortem extravascular alveolar tissue volume and alveolar surface area, were not significantly different from control. We conclude that targeted inhalational delivery of exogenous Epo improved post‐PNX pulmonary microvascular blood volume distribution and modestly augmented alveolar angiogenesis. Treatment did not significantly alter extravascular alveolar tissue growth, regional lung mechanics or physiological function measured at rest.

Support or Funding Information

Supported by NHLBI R01 HL40070 and U01 HL111146.
Development of a Poly(Lactic Acid) and Fibrin Device for Use in Bone Regenerative Medicine
Authors: Carvalho Renata Aquino , Júnior Valmir Vieira Rocha , Silva Eraldo Jannone , Trovatti Eliane , da Costa Iemma Monica Rosas , Amaral André Capaldo
Published: November 2023

Bone regenerative medicine aims to overcome the limitations of the conventional treatments for bone repair in attempt to develop therapeutic strategies based on biomaterials capable of acting as temporary substitutes for guiding and stimulating the tissue repair, in order to reduce or eliminate the need for autologous donor tissues. The aim of this study was develop a Poly(lactic acid) (PLA) and fibrin cellularized bioactive scaffold to establish a new strategy with potential to use in bone regenerative medicine. For this purpose, three‐dimensional PLA scaffolds were initialy produced by Fused Deposition Modeling (FDM) 3D printing technique, using computer aided drawing (CAD) software. These scaffolds were embedded in the suspension containing human pure platelet‐rich plasma (hP‐PRP) and human infrapatellar fat pad derived mesenchymal stem cells. Then, the platelets were exogenously activated by thrombin and calcium chloride, leading the fibrin to polymerize and form a cellularized device. The scaffolds were maintained in serum‐free Dulbecco's Modified Eagle Medium for 5 days. Scanning electron microscopy and fluorescence microscopy demonstrated that cells kept viable and in tree‐dimensional conformation during the experimental period of time. The results suggest that PLA scaffolds, associated with hP‐PRP fibrin matrix, generated a rigid bioactive scaffold capable of mantain cellular viability and represent a promising strategy for bone regenerative medicine.

Support or Funding Information

FUNADESP‐ Fundação Nacional de Desenvolvimento do Ensino Superior Particular
Isolation and Expansion of “Youthful” Bone Marrow Mesenchymal Stem Cells from Elderly Individuals
Authors: Block Travis Jackson , Marinkovic Milos , Tran Olivia , Dean David D , Chen Xiao‐Dong
Published: November 2023

Due to increased life expectancy, age‐related degenerative diseases are becoming an important public health concern. Although researchers have actively pursued stem cell‐based therapies for retarding or reversing age‐related degeneration, the results of clinical trials aimed at demonstrating stem cell efficacy have been inconsistent. Unfortunately, progress in developing autologous mesenchymal stem cell (MSC)‐based therapies has been impeded by the fact that MSC quantity and quality decline with aging. Since elderly patients are the main target population for cell‐based treatment of age‐related diseases, it is essential that a reproducible strategy for providing sufficient quantities of high‐quality autologous cells be developed and rigorously tested. In the present study, we propose that the ratio of young to old (aged) stem cells in the BM‐MSC population reverses with aging and that old MSCs not only lose their self‐renewal and differentiation capacity, but also release harmful factors that damage and/or suppress the younger “healthy” sub‐population of MSCs. These changes result in an inexorable functional decline of the overall elderly MSC population. Here, we test the hypothesis that MSCs from elderly patients can be rejuvenated by: 1) isolating a sub‐population of more “youthful” cells, using biomarkers (size and SSEA‐4 expression), from the original population of elderly MSCs; and 2) preserving and expanding this “youthful” sub‐population by culture on a “young microenvironment” using our established technology (BM‐ECM produced by young cells). We demonstrate that it is possible to obtain large quantities of MSCs that are functionally and phenotypically similar to MSCs from young donors from elderly donors whose overall cell populations are highly compromised. The results are provocative and suggest that it may be feasible to bank large quantities of high‐quality autologous MSCs for treatment of age‐related diseases.

Support or Funding Information

This study was supported by a VA Merit Review (1I01BX002145‐01) to X‐D Chen the National Institutes of Health, National Center for Advancing Translational Sciences (NIH/NCATS, UL1 TR001119).
Angiotensin‐(1‐7) Treatment Aids in the Recovery of Skeletal Muscle Function After Acute Injury in Rats
Authors: Criswell Tracy , Zhou Yu , Yoseph Benyam
Published: November 2023

Introduction

Pathologic fibrosis is a major impedance to the recovery of muscle function after injury, and is augmented in the elderly population. Angiotensin‐(1‐7) [Ang‐(1‐7)] is an endogenous, 7‐amino acid peptide hormone of the renin‐angiotensin system, which has been shown to reduce fibrosis in the heart, lung and kidney. The objective of this research was to examine the effect of Ang‐(1‐7) treatment on the recovery of muscle function in older rats after compression injury.

Methods

Compression injury was induced in the hind limbs of 12 month old male Lewis rats as previously described1. Ang‐(1‐7) was delivered at a dose of 24 μg/kg/hr by an osmotic pump implanted immediately after injury. Muscle function was measured via peroneal nerve stimulation. The tibialis anterior (TA) muscles were collected at day 14 after injury and processed for histological analyses and quantitative PCR (qPCR) analyses.

Results

Our data showed that treatment with Ang‐(1‐7) significantly increased muscle function 7 and 14 days after injury. However, we did not find any significant changes in fibrosis with Ang‐(1‐7) treatment.

Conclusions

Our data suggests that Ang‐(1‐7) may be acting directly on the muscle tissue and/or the local microenvironment in order to promote restoration of muscle function.

Support or Funding Information

Supported by pilot funding from the Wake Forest Baptist Health Hypertension and Vascular Research Center
Interprofessional Education in Anatomy: Using Q Methodology to Determine Student Perceptions
Authors: Mackinnon Chelsea , Akhtar‐Danesh Noori , Palombella Andrew , Wainman Bruce
Published: November 2023

Interprofessional education (IPE) is critical for preparing healthcare students for the collaborative components of their future careers. Anatomic dissection is an ideal IPE activity because all healthcare professionals require anatomy training and dissection demands extensive student interaction in a sensitive environment. The purpose of this study was to determine which aspects healthcare students perceived to contribute to the development of their (individual) interprofessional skillset within the context of McMaster University's 10‐week IPE gross anatomy dissection course.

We used Q‐methodology to identify the students' common viewpoints regarding the course. A total of 26 students from the Medical, Nursing, Midwifery, Physician Assistants, Occupational Therapy and Physiotherapy programs participated in this study. Students were asked to sort a Q‐sample of 43 statements based on their viewpoints regarding the IPE dissection course. The 43 statements were developed from interviews with students who had previously completed the course.

Using the centroid factor extraction and varimax rotation, three salient factors (groups) emerged. The groups were named based on distinguishing statements as follows: 1) Anatomy IPE Enthusiasts; 2) Practical IPE Advocates; 3) Skeptical IPE Anatomists. The Anatomy IPE Enthusiasts believed that students from different disciplines brought unique anatomical knowledge and each group member guided others through difficult material. The Practical IPE Advocates expressed that they would be much stronger advocates for interprofessional teams in the future as a result of taking the course. The Skeptical IPE Anatomists strongly disagree that learning with students from different disciplines helped them gain a solid understanding of their roles in the context of other healthcare professionals, and felt that there was not much benefit from the IPE program compared to other non‐interdisciplinary programs.

It is critical to understand student perceptions of IPE programs in order to best prepare these students for their future collaborative careers. These findings can help the course developers make further adjustments in the course structure, content and delivery to address some of the issues highlighted by the students, and to further emphasize the topics that were well‐received by the students. Finally, we hope that these results will be helpful to other interprofessional educators, especially those whose program has an anatomy framework.
Student Perceived Difficulties in Learning Organ Systems in an Undergraduate Human Anatomy Course
Authors: Shaffer Justin , Lieu Rebekah , Gutierrez Andrew
Published: November 2023

Undergraduate human anatomy courses are often taught with a systems approach by teaching one system at a time, often starting with the skeletal system, then the muscular system, then the nervous system, and so on. When learning about systems sequentially, students will likely perceive certain systems to be more or less difficult than others for various reasons which may contribute to their actual learning of each system. Having an understanding of why students find certain organ systems to be more or less challenging can inform instruction in order to help students learn about organ systems more effectively. The objectives of this study were to determine how students perceived each organ system in terms of difficulty and to determine why students thought certain organ systems were more or less challenging. Student survey data were analyzed from two sections of a large enrollment (~125 students) undergraduate human anatomy course at a large research university in the western United States. A pre‐post survey was used to assess changes in student confidence regarding their knowledge of organ systems and qualitative methods based on grounded theory were used to analyze student written data from a post‐survey that asked students to explain why they thought certain organ systems were difficult to learn. Results showed that while students reported significantly increased confidence in all organ systems by the end of the course, the gains were lowest for the central and peripheral nervous systems. At the end of the course, students perceived the central and peripheral nervous systems to be most difficult organ systems to learn (reported by students in written comments to be largely due to the complexity of the structure‐function relationships within these systems). Students also perceived the cardiovascular system to be least difficult to learn (because of their familiarity with the system from prior courses). These results suggest that undergraduate human anatomy students perceive organ systems as more or less challenging for a variety of reasons ranging from properties inherent to each system (e.g. complexity of systems and structure‐function relationships, quantity of structures, etc) to logistical factors regarding each system (e.g. exposure through pre‐requisites, time spent on a system, etc). These findings have practical implications in that anatomy instructors may choose to alter their course curriculum or design pedagogical activities that specifically address the reasons why students perceive organ systems as more or less challenging in order to improve student learning.

Support or Funding Information

N/A
INTERNATIONALIZATION OF MEDICAL EDUCATION – A PILOT STUDY USING A SHARED DIGITAL DISSECTOR AND EARLY PEER‐TO‐PEER STUDENT INTERACTION IN AMERICAN AND GERMAN CLINICAL GROSS ANATOMY COURSES
Authors: Wu Anette , Goelkel Camilla , Chiuzan Codruta , Duong Jimmy , Kielstein Heike , Bernd Paulette
Published: November 2023

Background

Internationalization of medical education is important at a time of globalization and population migration. It can occur on several levels.

The purpose of this pilot study was to address internationalization of medical education in the Clinical Gross Anatomy course in two areas ‐ on the student level via early peer‐to‐peer communication and on the teacher level via international exchange of teaching material.

Material and Methods

In the current pilot study we a) applied real‐time videoconferencing during the Clinical Gross Anatomy course to connect junior medical students from Germany and the United States and b) tested a US written digital iPad operated Anatomy dissector at a medical school in Germany. Questionnaires were sent to the students to get feedback on their experience with their international counterparts. Checklists were collected in order to get objective measures for successful adaption of the dissector into the German curriculum. Questionnaires were sent to the users of the iPad dissector.

Results

a) the majority of the students liked the international experience and asked for more sessions, as well as more structured interactions; b) the US written iPad operated dissector was liked by the users and easily adapted into a German Anatomy curriculum and resulted in equal if not better dissection results.

Conclusion

Internationalization of medical education on the student level and teacher level is possible and welcomed by students. Starting peer‐to‐peer interaction early in the Anatomy course can give Anatomy courses a new role in international medical education.

Support or Funding Information

Grant of the Virgina Apgar Academy of Medical Educators, Columbia University
Navigating Your First Cut: A Hands‐off Animated Guide to the First Year Anatomy Lab
Authors: Garabedian Maryam , Rothman Zachary , Fejtek Monika , Vo Lien , Krebs Claudia
Published: November 2023

Knowledge of gross anatomy is a critical component of a medical student's education. An understanding of human anatomy is equally essential for the practicing clinician. Historically, schools have solely used cadaver dissections to teach the anatomical sciences. However, lab sessions can be overwhelming, in particular the first session. Students in their first year of medical school are confronted with so many unknowns, and they struggle to prepare mentally and academically for the experience. Where do you cut? What is underneath, beside, above, or below what you are cutting? What are you looking for? A learner, who is yet unfamiliar with the terms, may find written instructions for the dissection difficult to understand. So how does one enhance learning of gross anatomy? In recent years, many medical schools have supplemented cadaver dissections with multimedia, where as others have completely replaced cadaver dissections with prosections or multimedia. We pursued the former method to improve learning: creating an animated video guide for the first gross anatomy dissection in the first year medical undergraduate curriculum. The video takes the learners through the technical and academic steps of their first dissection. And for many students, the video was their first real look at what dissection looks and sounds like. The aim was to alleviate some of the anxieties as students enter this transformative component of their education. We surveyed the students before and after they completed the lab to understand whether the video was helpful. An overwhelming majority of respondents rated the video as very helpful in preparing them for this experience. Some of the comments included: “It was really helpful to see a cadaver being cut before having to do [the dissection] to help mentally prepare” and “The video could not have prepared me better”. In addition, nearly all respondents said they would like to see more videos in the future. Given its reception, we conclude that this visual guide served to optimize the students' gross anatomy experience, and thus their learning and understanding of the material.
Use and Perceptions of Plastination Among Anatomy Medical Educators in the United States
Authors: Klaus Rachel , Royer Danielle , Corral Janet , Stabio Maureen E.
Published: November 2023

Traditionally, medical schools have maintained collections of cadaveric tissues and organs to engage students in anatomy. Such collections are often stored in preservative solutions that are toxic, volatile and carcinogenic. Plastination is an alternative tissue preservation technique in which the water and lipids are replaced with polymers. Thus, the tissues are as benign as a manufactured plastic model, yet anatomically authentic. Plastination was popularized by Body Worlds and Body Works exhibits and is used in medical education internationally; however, its use within U.S. medical schools is not widely discussed in the anatomical literature. Among the 786 peer‐reviewed articles about plastination from 1977–2016, 15% are from U.S. institutions. The objective of this study was to determine the use and perceptions of plastination as an anatomical teaching tool among medical educators in the U.S. A 16‐item survey was developed in Qualtrics and approved by the Colorado Multiple Institutional Review Board. Question types included multiple choice, free response, semantic differential, dichotomous and contingency based. Survey items focused on four main areas: (1) availability and use of cadaveric dissection, (2) familiarity with plastination, (3) integrations of plastination in current curriculum, and (4) perceptions of plastination as a teaching tool. Survey invitations were posted on the American Association of Anatomists Open Forum and emailed to anatomy course directors at 139 allopathic (MD) and 38 osteopathic (DO) schools nationally. Descriptive statistics were performed using SAS. 120 U.S. anatomists completed the survey; 68% indicated they teach MD students (n=81), and 19% teach DO students (n=23). Analysis was restricted to these 98 respondents representing 77 medical schools across 37 states. Of these, 100% had heard of plastination, 78% had attended a Body Worlds and Body Works exhibit, but less than 40% currently utilize plastinates for medical anatomy education. When prompted to explain why plastination is not used, several themes emerged. Most prominently was a preference for the dissection experienced, followed by cost, availability, lack of resources and negative past experiences related to durability and quality. 75% of medical anatomy educators perceived plastination as a good supplement to, but not a replacement for, dissection, 19% indicated no curiosity to use plastination or considered it not useful, 10% expressed ethical concerns about plastination in general, and only 1% considered plastination a good alternative to replace dissection. These findings suggest that plastinates are more widely used in the U.S. than reflected by the literature; however, perceptions regarding their utility are varied with a dominant theme towards their use to supplement, but not replace, cadaveric dissection.
Contributing to the future of diversity in medicine: A powerful outreach program at the SUNY Downstate College of Medicine
Authors: Diaz Ana , Jones Tashzna , Pagano Anthony S , Márquez Samuel
Published: November 2023

The Health Professions Recruitment and Exposure Program (HPREP) at Downstate is a powerful education outreach platform that promotes and supports pools of under represented students interested in choosing careers in medicine and other health care professions. Despite a steady increase in the proportion of the American population comprised of racial and ethnic minority groups, the percentage of minority physicians has remained relatively stagnant over the last 20 years. African Americans, Hispanics and Native Americans comprise 26% of the U.S. population yet make up only 6% of practicing physicians.1 The Health Professions Recruitment and Exposure Program (HPREP) at Downstate aims to minimize this disparity by offering 30 minority high school students in 9th through 11th grade the opportunity to engage in lectures and participate in small group workshops where they learn anatomy, physiology, and some practical clinical applications of the basic sciences. With the help of medical student facilitators, many of whom are also from minority groups, program participants complete a research project on a pre‐approved topic for presentation during the final week of the program. Pre‐ and post‐tests are carried out at each session in order to quantify student learning by grade‐level. Results have shown consistent significant (P<0.05) improvement between pre‐ and post‐test scores as of their first use in 2014. In addition, a pre‐ and post‐program questionnaire is given to assess the program's impact on students' intent to pursue a career as a health professional with the vast majority of participants answering favorably. As HPREP offers early exposure to minorities underrepresented in medicine, it is our goal to better prepare them for completing the rigors required for successful entrance into the field, thereby bringing greater diversity to the physician workforce.
Anatomical Connections: Linking High Schools to the UVM College of Medicine with Anatomy
Authors: McCarthy Sarah A , Flynn Sean P , Merrill Liana
Published: November 2023

The University of Vermont, as the largest post‐secondary school and home of the only medical school in the state, has a strong commitment to community outreach and education. The Robert Larner, M.D. College of Medicine at the University of Vermont has a strong history of outreach that we aimed to expand by designing an anatomy‐based program connecting educators and students at UVM with their peers in local high schools. Many high schools in Vermont do not have the resources to offer anatomy and physiology courses despite the fact that many of their students are interested in the biomedical field. The purpose of our work was to build strong working relationships with local high school teachers in the Champlain Valley area of Vermont in an effort to begin a mentoring program between high school students and UVM students. Our outreach event occurred over two days: one focused on building relationships with high school teachers and the second focused on high school students. Nine high school science teachers attended the first day, which included a visit to the gross anatomy laboratory to view available resources for future collaboration. Teachers then attended a lunch seminar focused on effective mentoring. Finally, there was a session on developing and designing an anatomy and physiology course for high school students. Surprisingly, the greatest benefit of the teacher day was the opportunity for other high school teachers to meet and discuss their anatomy and physiology courses. Twenty high school sophomore and junior students attended the second portion of the program. It started with a session in the gross anatomy laboratory viewing anatomical specimens led by medical and graduate students. Following morning anatomy demonstrations, we invited everyone to stay for a lunch lecture focused on getting the most out of mentoring relationships. After lunch, we broke the high school students into small groups led by graduate and medical students based on their interests in topics such as college applications, interviews, and post high school opportunities. Each session was evaluated by the participants to determine the effectiveness of the program and whether future sessions would be beneficial for the students. The students were very enthusiastic about meeting students in higher education and having the opportunity to discuss their future with them. Based on our pilot year, we hope to grow our program into a formal mentoring network between medical/graduate students and high school students that will expand beyond one day. We will continue to foster our relationships with local high school teachers to ensure the growth of such a program.

Support or Funding Information

This work was supported by a Outreach Grant from the American Association of Anatomists.
Integrating Clinical Medicine with the Basic Sciences: Musculoskeletal System Cadaver‐Based Learning Module for Medical Students
Authors: Doroudi Majid , Majdzadeh Ali , Wong Alex , Nouraei Hirman
Published: November 2023

In undergraduate medical education, there has traditionally been a focus on the basic sciences, cornerstones of which include anatomy and clinical skills. However, there is concern among some practicing clinicians that the pre‐clinical knowledge of medical students in anatomy and clinical skills could be improved to allow for safer and more effective medical practice. Clinical skills education often draws on the anatomy that students learn in the anatomy lab, and both topics are often studied in parallel. However, the anatomy curriculum seldom underscores the relevance of anatomical features and their direct correlations with clinical skills and examination techniques. As such, we hypothesize that by developing an online module which employs cadaver‐based teaching of anatomy with enhanced context provided by clinical skills cases and examinations, students will achieve a better appreciation and understanding of the underlying anatomical pathology that is often manifested clinically, and that this will facilitate their overall learning of anatomy. Accordingly, an online module was developed for 2nd year UBC medical students which focused on the lower limb musculoskeletal anatomy, as well as the pertinent clinical tests. Overall, 101 students provided feedback and 95% expressed that the module had successfully enabled them to better consider the correlation between anatomy and clinical skills. We conclude that cadaver‐based modules are effective for reviewing the anatomy content and the integration of clinical relevance further facilitates this process, while also bridging the gap between these two domains.
An Innovative 3 Dimensional Model of Middle Ear
Authors: Dixit Shilpi Gupta , Dixit Abhinav , Ghatak Surajit
Published: November 2023

Objective

The study of anatomy is generally related to identifying various structures and their spatial relationships with respect to each other. Physical models are particularly useful in demonstrating complex topics or those ones that are difficult to access when seen in the textbook or cadaver. One such topic is middle ear. Aim of the present study was to introduce a muticoloured cardboard model of middle ear to provide ease in understanding of its anatomical structure.

Methods

It was a qualitative research study. The participants were 2nd semester medical undergraduate class of 78 students. They were exposed to a cuboidal multicolored model (made from cardboard box) with 6 walls that could be opened to see the details of structures related to them. Student feedback was taken through a structured Questionnaire based on Likert Scale (5 to 1).

Results

More than 80% of students (n=78) felt that this model was a good tool for visualizing complex anatomy of middle ear in small groups and it reduced the time needed for self‐study. This model provided multifaceted feedback with active participation from students. A low fidelity middle ear model proved to be a practical low cost tool for use in both didactic and small group teaching.

Conclusion

A strong foundation of understanding anatomy requires appreciation of complex 3D spatial relationships and mutual 3D visualization skills. Low fidelity models continue to have a place in anatomy and can be integrated in the current curriculum.

Support or Funding Information

No funding was needed
The Promise of Mixed Reality in Anatomy Education
Authors: Romaniuk Michael , Lamb Jason , Mitchell Josh , Bayer Ilana , Wainman Bruce
Published: November 2023

We have previously demonstrated that when anatomy is learned from traditional 3D computer models (i.e., those projected on flat screens) or using pictures and diagrams of specimens, test scores are approximately 30% less than when the anatomy is learned from solid models when students are tested on cadavers. We have shown that these traditional, computer generated 3D images are perceived as 2D images due to our use of 2D‐displays. Our current goal is to utilize technology that allow our learners to perceive these computer objects as true 3D models i.e., as solid objects. Recent developments in technology, like the Microsoft HoloLens, allow us to generate convincing, interactive, 3D models in real space. These mixed‐reality anatomic objects have the potential to be as efficient as our solid models in learning anatomy and thus may replace the traditional tools of anatomic teaching. This presentation will demonstrate anatomic specimens in all formats, including mixed reality applications in an interactive setting to emphasize the benefits and problems of each form of learning object.

Support or Funding Information

Education Services, Faculty of Health Sciences and MacPherson Institute, McMaster University.
The Use Of Nigrosin Staining To Increase Brain Slice Contrast For Neuroanatomy Teaching
Authors: Saraco Anthony N. , MacPhee Neil , Ball Alexander K. , Wainman Bruce C.
Published: November 2023

Although plastic models and electronic resources play an important role in demonstrating concepts in neuroanatomy, the study of human cadaver brain remains important where it is necessary to illustrate detail, spatial relationships, or in clinical teaching. The most difficult structures to visualize in embalmed brains are the deep cerebral and cerebellar nuclei due to the muted contrast after embalming. Many contrast enhancing staining protocols have several drawbacks including vague published protocols, variability of staining, the need for counter‐stains, or the length of the staining process. The purpose of our study was to evaluate several simple stains and protocols that would be effective in increasing grey matter contrast in brain slices.

Whole brains were extracted from cadavers fixed with 65% ethanol, 10% propylene glycol, 4% phenol, 4% Dettol and 2% formalin after 10–12 months. Brains were postfixed with 10% formalin for 2–3 weeks before use. Two Plexiglas frames were constructed with horizontal (transverse) or vertical (coronal) slits spaced 1 cm apart to facilitate the cutting of serial sections. Serial transverse or coronal slices of brains were washed in tap water for 1 min prior to staining. Brain slices were stained in various dilutions of aqueous toluidine blue, cresyl violet, or Nigrosin. The contrast between grey and white matter was measured with a standardized camera and image analysis was performed on 8‐bit images using Image‐J. Overstained or understained sections were obtained with all protocols except Nigrosin. The most successful staining was obtained on sections stained with 0.5% aqueous Nigrosin for 15 min followed by clearing in a series of water and ethanol rinses. Sections were stored on a stainless steel tray covered with a moist cloth for various times before quantitative analyses was performed. The depth of staining was evaluated in sections cut tangential to the stained surface. The robustness of the staining was evaluated in sections stored in water, 2% aqueous glycerol, 100% ethanol, or 100% acetone for various times up to 4 wks.

We conclude that the staining of brain sections with Nigrosin provides high contrast differentiation of grey and white matter. Interestingly, details of white matter tracts became visible but certain deep brain nuclei were consistently unstained. There was minimal fading of the staining after storage in organic and inorganic solvents indicating that the method may be useful for long term storage as both wet or plastinated specimens. Nigrosin staining of brain slices serves as a simple method to increase the visibility of brain structures for the study of neuroanatomy.

Support or Funding Information

Education Program in Anatomy, McMaster University
Evidence that studying histology improves students' spatial ability
Authors: Schmalz Naomi A , Condon Keith W , Brokaw James J
Published: November 2023

Spatial ability has been defined as the capacity to think about objects in three dimensions, as for example, the ability to visualize how a 3D object would look when mentally‐rotated in space. There is a general consensus that spatial ability is correlated with course performance in gross anatomy, and that spatial ability can be improved with practice and certain kinds of training. However, few studies have examined the role of spatial ability in histology. We sought to determine whether students' spatial ability can be improved simply by taking a graduate histology course in which glass slides are examined with optical microscopes. From 2013–2015, we administered the 20‐question Purdue Visualization of Rotation Test (VORT) at the beginning of the course (pre‐VORT) and again approximately 14 weeks later at the end of the course (post‐VORT). All students agreed to participate (n = 65). At baseline, the mean ± SD pre‐VORT score was 13.62 ± 4.46 for the males (n = 29) and 11.33 ± 4.52 for the females (n = 36). At the end of the course, the post‐VORT score had increased by 7.6% in the males (14.66 ± 4.06; p = 0.011, Wilcoxon Signed Rank Test for paired data) and by 10.9% in the females (12.56 ± 4.23; p = 0.036). When the analysis was confined to students whose baseline spatial ability was low to average at the start of the course (defined as pre‐VORT scores at the 50th percentile or below, i.e., the bottom half of the class) the improvement in spatial ability was more striking. For the males in this category (n = 15), their mean VORT score increased from 9.87 ± 2.10 at the beginning of the course to 11.80 ± 2.93 at the end of the course – a 19.6% increase (p = 0.002, Wilcoxon Signed Rank Test for paired data). For the females in this category (n = 19), their mean VORT score increased from 7.95 ± 2.88 at the beginning of the course to 10.42 ± 4.03 at the end of the course – a 31.1% increase (p = 0.009). These results suggest that studying histology with glass slides and optical microscopes can passively improve students' spatial ability as measured by a mental rotation test, and that the greatest benefit is accrued by female learners.
Mitochondria Adjacent to Ribbon Synapses in Vestibular Hair Cells Are Not Polarized Toward the Synapse
Authors: Jayakumar Ashik , Ghatalah Laila , Perkins Guy , Lysakowski Anna
Published: November 2023

Mitochondria are generally known as “the powerhouses of the cell”. In our research, 3D models of mitochondria in vestibular hair cells were constructed from electron microscope (EM) tomograms to understand the structural role of their internal cristae in support of neuronal activity at ribbon synapses. The mitochondrial inner compartment is made up of the, the inner membrane and the cristae. Recent EM tomography studies have shown us that these two membrane domains are connected by small tubular structures known as crista junctions (CJs). CJs “have been proposed to regulate the dynamic distribution of proteins, lipids, and soluble metabolites between mitochondrial subcompartments” (Zick et al. 2009). Mitochondrial cristae are the location of most of the enzymes and is responsible for cellular respiration and ATP production, and therefore play an essential role in cellular activities. A ribbon synapse is known to be a ‘high capacity docking site’ of synaptic vesicles that provide the fusion sites for ‘active zones’ and they are known to have a large supply of “immobile synaptic vesicles rapidly available for exocytosis” (Schmitz et al. 1996). The vesicles are powered by ATP produced by mitochondria. The goal of this study was to test the hypothesis of whether the distance of a mitochondrion from a synapse would have an influence on the number of cristae junctions(CJs) on the mitochondrion. Our hypothesis is that cristae that are present in the mitochondrion, are oriented perpendicular to the ribbon and would be expected to demonstrate a higher number of CJs on the side of the mitochondrion facing the ribbon synapse. Using our reconstructions, the number of CJs present in a mitochondrion is counted. In our tomograms, we observed that the ratio of CJs towards the ribbon to the CJs away from the ribbon synapse is close to 1:1 regardless of the distance from the ribbon synapse. From this we can conclude, despite the cristae being oriented perpendicular to the ribbon synapse, distance from the synapse apparently does not affect whether CJs are more prevalent on the side adjacent to the synaptic ribbon in vestibular hair cells.

Support or Funding Information

NIH R21‐DC013181 and P41‐RR004050
Assessing the Asymmetrical Distribution of Crista Junctions in Tubular Mitochondria Located Adjacent to a Post‐Synaptic Density of a Vestibular Hair Cell Ribbon Synapse
Authors: Vazirian Saeed , Babu Vidya , Perkins Guy , Lysakowski Anna
Published: November 2023

Mitochondria are energy processing organelles in most cell types, essential for maintaining major cellular functions by ATP production, such as the cell‐to‐cell signaling of neurons in the mammalian nervous system. Inner ear hair cells, like all cells, use the mitochondrial machinery for their normal functioning (Song et al., 2013). The structure of these organelles, consequently, has implications for the healthy function of inner ear hair cells and impairments are the cause of certain forms of deafness and imbalance. As a double‐membraned organelle, the inner membranes of mitochondria includes the inner mitochondrial membrane and the cristae. Electron microscopic tomography (EMT) reveal that these two inner portions of mitochondria articulate with each other via narrow tubular‐shaped openings known as crista junctions (CJs) (Song et al., 2013). These structures are probably dynamic, with CJs forming and disintegrating in response to environmental changes, mitochondrial shape changes, inner membrane surface area variations or nutrient transport to the mitochondrion (Perkins and Ellisman, 2007). For this study, we predicted an asymmetrical distribution of crista junctions in mitochondria with tubular cristae located in the calyxplasm of a vestibular calyx ending adjacent to a post‐synaptic density at a ribbon synapse in a vestibular hair cell. Synaptic ribbons are the form that synapses take in retinal photoreceptors and inner ear hair cells, consisting of synaptic vesicles and an electron‐dense “ribbon” or docking site, and they are the location of vesicle fusion during active neurotransmitter release (Schmitz et al., 1996). Using the EM tomograms and 3‐D imaging software called IMOD, qualitative and computational data can be obtained on these mitochondria including their tubular cristae and CJ numbers, shape, distribution and even the density of the matrix (Tasel et al., 2016). With these tools, we hypothesized that a statistically significantly larger number of CJs will appear on the sides of mitochondria near the ribbon synapse, as opposed to away from it. Furthermore, we expect metabolic activity at the synapse to also be higher, as ATP is required for signaling activity of the ribbon synapse provided by the tubular cristae (Perkins and Ellisman, 2007). Calculations, with the help of the IMOD software has helped us bear out these assumptions, using information on the number, total volume and other details on CJs of vestibular hair cells (Tasel et al., 2016) (Song et al., 2013).

Support or Funding Information

Supported by NIH R21‐DC013181 (AL) and P41‐RR004050 (GP, ME).
ENERGY OUTPUT CHARACTERISTICS OF EFFERENT BOUTON MITOCHONDRIA OF THE INNER EAR
Authors: Kambalyal Anuj Channu , Sobkiv Sofia , Perkins Guy , Lysakowski Anna
Published: November 2023

Mitochondria produce ATP to power many functions in cells throughout the body. The current depiction of a mitochondrion, containing an inner membrane (IM), outer membrane and cristae that increase the surface area of the IM, has been the universally accepted model for decades. Although the basic function and structure of mitochondria have been studied for many years, recent analyses based upon data gathered from electron microscopy (EM) has led to further investigations of mitochondria (Rabl et al., 2009; Zick et al., 2009). We have been using IMOD software (Univ. of Colorado, Boulder) to reconstruct mitochondria located near different high energy‐demanding intracellular components and have obtained new quantitative data. In efferent boutons coming from the brainstem to contact vestibular calyx endings in the inner ear, we have observed tubular crista morphology, thought to be a lower‐energy form of mitochondria compared to the lamellar morphology found in most neurons. We have used the values obtained for total crista surface area in our 3D reconstructions to calculate both the rate of ATP production (Song et al., 2013) and the amount of energy produced by this type of mitochondrion. Our values are 250–350 zeptomoles of ATP/sec and 8–10 femtojoules of energy, compared to roughly 1000 zeptomoles of ATP/sec and 25–50 femtojoules of energy for more typical lamellar cristae. Thus, we can confirm that tubular cristae in efferent boutons contacting vestibular calyx endings in the inner ear do indeed produce less ATP and less energy. The implications of this level of ATP production or energy output on hair cell or afferent function are unknown at this time, but will be the subject of future research.

Support or Funding Information

Supported by NIH R21‐DC013181 (AL) and P41‐RR004050 (GP, ME)