scholarly journals Teaching bioelectricity and neurophysiology to medical students using LabAXON simulations

2021 ◽  
Vol 45 (4) ◽  
pp. 702-708
Author(s):  
Olivia Monteiro ◽  
Anand Bhaskar ◽  
Io Nam Wong ◽  
Anna K. M. Ng ◽  
Daniel T. Baptista-Hon
Keyword(s):  
Medical Students ◽  
Action Potential ◽  
Simulation Software ◽  
Multiple Choice Questions ◽  
Voltage Gated ◽  
Quantitative Measurements ◽  
Lecture Material ◽  
Electrophysiological Recordings ◽  
Recovery From Inactivation ◽  
Relationship Of

Patch-clamp electrophysiological recordings of neuronal activity require a large amount of space and equipment. The technique is difficult to master and not conducive to demonstration to more than a few medical students. Therefore, neurophysiological education is mostly limited to classroom-based pedagogies such as lectures. However, the demonstration of concepts such as changes in membrane potential and ion channel activity is best achieved with hands-on approaches. This article details an in silico activity suitable for large groups of medical students that demonstrates the key concepts in neurophysiology using the LabAXON simulation software. Learning activities in our practical include 1) measurements of voltage and time parameters of the neuronal action potential and its relationship to the Nernst potentials of Na+ and K+; 2) determination of the stimulus threshold to evoke action potentials; 3) demonstration of the refractory period of an action potential; and 4) voltage-clamp experiments to determine the current-voltage relationship of voltage-gated Na+ and K+ channels and the voltage dependence of, and recovery from, inactivation of voltage-gated Na+ channels. We emphasized the accuracy of quantitative measurements as well as the correct use of units. The level of difficulty of the activity can be altered through different multiple choice questions relating to material introduced in the associated lectures. This practical activity is suitable for different class sizes and is adaptable for delivery with online platforms. Student feedback showed that the students felt the activity helped them consolidate their understanding of the lecture material.

I A in Kenyon Cells of the Mushroom Body of Honeybees Resembles Shaker Currents: Kinetics, Modulation by K+, and Simulation

1999 ◽  
Vol 81 (4) ◽  
pp. 1749-1759 ◽  
Author(s):  
Corinna Pelz ◽  
Johannes Jander ◽  
Hendrik Rosenboom ◽  
Martin Hammer ◽  
Randolf Menzel
Keyword(s):  
Action Potential ◽  
Time Constant ◽  
Mushroom Body ◽  
Delayed Rectifier ◽  
Patch Clamp Technique ◽  
Time Constants ◽  
Voltage Gated ◽  
Kenyon Cells ◽  
Recovery From Inactivation ◽  
A Current

I A in Kenyon cells of the mushroom body of honeybees resembles shaker currents: kinetics, modulation by K+, and simulation. Cultured Kenyon cells from the mushroom body of the honeybee, Apis mellifera, show a voltage-gated, fast transient K+ current that is sensitive to 4-aminopyridine, an A current. The kinetic properties of this A current and its modulation by extracellular K+ ions were investigated in vitro with the whole cell patch-clamp technique. The A current was isolated from other voltage-gated currents either pharmacologically or with suitable voltage-clamp protocols. Hodgkin- and Huxley-style mathematical equations were used for the description of this current and for the simulation of action potentials in a Kenyon cell model. Activation and inactivation of the A current are fast and voltage dependent with time constants of 0.4 ± 0.1 ms (means ± SE) at +45 mV and 3.0 ± 1.6 ms at +45 mV, respectively. The pronounced voltage dependence of the inactivation kinetics indicates that at least a part of this current of the honeybee Kenyon cells is a shaker-like current. Deactivation and recovery from inactivation also show voltage dependency. The time constant of deactivation has a value of 0.4 ± 0.1 ms at −75 mV. Recovery from inactivation needs a double-exponential function to be fitted adequately; the resulting time constants are 18 ± 3.1 ms for the fast and 745 ± 107 ms for the slow process at −75 mV. Half-maximal activation of the A current occurs at −0.7 ± 2.9 mV, and half-maximal inactivation occurs at −54.7 ± 2.4 mV. An increase in the extracellular K+concentration increases the conductance and accelerates the recovery from inactivation of the A current, affecting the slow but not the fast time constant. With respect to these modulations the current under investigation resembles some of the shaker-like currents. The data of the A current were incorporated into a reduced computational model of the voltage-gated currents of Kenyon cells. In addition, the model contained a delayed rectifier K+ current, a Na+current, and a leakage current. The model is able to generate an action potential on current injection. The model predicts that the A current causes repolarization of the action potential but not a delay in the initiation of the action potential. It further predicts that the activation of the delayed rectifier K+ current is too slow to contribute markedly to repolarization during a single action potential. Because of its fast activation, the A current reduces the amplitude of the net depolarizing current and thus reduces the peak amplitude and the duration of the action potential.

scholarly journals The Role of Undegraduate Medical Students Training in Respect for Patient Confidentiality

2020 ◽  
Author(s):  
Cristina M Beltran-Aroca ◽  
Rafael Ruiz-Montero ◽  
Fernando Labella ◽  
Eloy Girela-López
Keyword(s):  
Medical Students ◽  
Clinical History ◽  
Multiple Choice Questions ◽  
Right To Privacy ◽  
The Right To Privacy ◽  
Direct Exposure ◽  
Spanish Universities ◽  
The Right ◽  
Relationship Of

Abstract IntroductionEncouraging professional integrity is vital in providing a standard of excellence in the quality of medical care and education, promoting a culture of respect and responsibility. The main objective of this work consisted of studying the relationship of medical students with the right to privacy of patients in Spain, specifically analysing the conditions of accessing patients’ Clinical History (CH).MethodsA questionnaire was sent to final-year students at 41 Spanish universities. It had 14 multiple choice questions framed in 3 large blocks. The first one addressed basic general knowledge issues on the right to privacy and the obligation of confidentiality. The two remaining blocks were made up of questions directed towards evaluating the frequency with which certain requirements and steps of action related to the students in attending the patient were performed, and regarding the guarantees in accessing and handling their CH both on paper and in the Electronic Medical Record.ResultsA total of 245 valid replies was considered. 67.8% of participants were women, with an average age of 24.05±3.49 years. Up to 90.6% were aware that confidentiality affected the data in CHs, although 43.3% possessed non-anonymized photocopies of patients’ clinical reports outside healthcare context, and only 49.8% of the students were always adequately identified. 59.2% accessed patients’ CHs on some occasions by using passwords of healthcare professionals and 77.2% of them did not have patients’ express consent and 71.9% accessed a CH that was not anonymised.ConclusionsThe role of healthcare institutions and universities is considered to be fundamental in implementing educational measures regarding the risks and ethical and legal problems arising from the use of CHs among professionals and students. A profound study of medical ethics is needed through the analysis of clinical cases, and direct exposure to situations in which the patient’s confidentiality is questioned.

scholarly journals Statistical Approach to Incorporating Experimental Variability into a Mathematical Model of the Voltage-Gated Na+ Channel and Human Atrial Action Potential

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1516
Author(s):  
Daniel Gratz ◽  
Alexander J Winkle ◽  
Seth H Weinberg ◽  
Thomas J Hund
Keyword(s):  
Action Potential ◽  
Mathematical Models ◽  
Cardiac Myocyte ◽  
Population Level ◽  
Na Channel ◽  
Model Parameters ◽  
Healthy Population ◽  
Experimental Measurements ◽  
Voltage Gated ◽  
Experimental Variability

The voltage-gated Na+ channel Nav1.5 is critical for normal cardiac myocyte excitability. Mathematical models have been widely used to study Nav1.5 function and link to a range of cardiac arrhythmias. There is growing appreciation for the importance of incorporating physiological heterogeneity observed even in a healthy population into mathematical models of the cardiac action potential. Here, we apply methods from Bayesian statistics to capture the variability in experimental measurements on human atrial Nav1.5 across experimental protocols and labs. This variability was used to define a physiological distribution for model parameters in a novel model formulation of Nav1.5, which was then incorporated into an existing human atrial action potential model. Model validation was performed by comparing the simulated distribution of action potential upstroke velocity measurements to experimental measurements from several different sources. Going forward, we hope to apply this approach to other major atrial ion channels to create a comprehensive model of the human atrial AP. We anticipate that such a model will be useful for understanding excitability at the population level, including variable drug response and penetrance of variants linked to inherited cardiac arrhythmia syndromes.

scholarly journals Coping with COVID-19: medical students as strong and responsible stewards of their education

2021 ◽  
Author(s):  
Jacquelyn B. Kercheval ◽  
Deena Khamees ◽  
Charles A. Keilin ◽  
Netana H. Markovitz ◽  
Eve D. Losman
Keyword(s):  
Medical Students ◽  
Curriculum Development ◽  
De Novo ◽  
Traditional Approach ◽  
Clinical Care ◽  
Successful Implementation ◽  
Discussion Boards ◽  
Multiple Choice Questions ◽  
Continued Learning ◽  
Comprehensive Curriculum

Abstract Background Due to the COVID-19 pandemic, clinical rotations at the University of Michigan Medical School (UMMS) were suspended on March 17, 2020, per the Association of American Medical Colleges’ recommendations. No alternative curriculum existed to fill the educational void for clinical students. The traditional approach to curriculum development was not feasible during the pandemic as faculty were redeployed to clinical care, and the immediate need for continued learning necessitated a new model. Approach One student developed an outline for an online course on pandemics based on peer-to-peer conversations regarding learners’ interests and needs, and she proposed that students author the content given the immediate need for a curriculum. Fifteen student volunteers developed content to fill knowledge gaps, and expert faculty reviewers confirmed that the student authors had successfully curated a comprehensive curriculum. Evaluation The crowdsourced student content coalesced into a 40-hour curriculum required for all 371 clinical-level students at UMMS. This student-driven effort took just 17 days from outline to implementation, and the final product is a full course comprising five modules, multiple choice questions, discussion boards, and assignments. Learners were surveyed to gauge success, and 93% rated this content as relevant to all medical students. Reflection The successful implementation of this model for curriculum development, grounded in the Master Adaptive Learner framework, suggests that medical students can be entrusted as stewards of their own education. As we return to a post-pandemic “normal,” this approach could be applied to the maintenance and de novo development of future curricula.

scholarly journals A sodium-activated potassium channel supports high-frequency firing and reduces energetic costs during rapid modulations of action potential amplitude

2013 ◽  
Vol 109 (7) ◽  
pp. 1713-1723 ◽  
Author(s):  
Michael R. Markham ◽  
Leonard K. Kaczmarek ◽  
Harold H. Zakon
Keyword(s):  
Action Potential ◽  
High Frequency ◽  
Electric Fish ◽  
Electric Organ Discharge ◽  
Electric Organ ◽  
Weakly Electric Fish ◽  
Energetic Costs ◽  
Dynamic Regulation ◽  
Voltage Gated

We investigated the ionic mechanisms that allow dynamic regulation of action potential (AP) amplitude as a means of regulating energetic costs of AP signaling. Weakly electric fish generate an electric organ discharge (EOD) by summing the APs of their electric organ cells (electrocytes). Some electric fish increase AP amplitude during active periods or social interactions and decrease AP amplitude when inactive, regulated by melanocortin peptide hormones. This modulates signal amplitude and conserves energy. The gymnotiform Eigenmannia virescens generates EODs at frequencies that can exceed 500 Hz, which is energetically challenging. We examined how E. virescens meets that challenge. E. virescens electrocytes exhibit a voltage-gated Na+current ( INa) with extremely rapid recovery from inactivation (τrecov= 0.3 ms) allowing complete recovery of Na+current between APs even in fish with the highest EOD frequencies. Electrocytes also possess an inwardly rectifying K+current and a Na+-activated K+current ( IKNa), the latter not yet identified in any gymnotiform species. In vitro application of melanocortins increases electrocyte AP amplitude and the magnitudes of all three currents, but increased IKNais a function of enhanced Na+influx. Numerical simulations suggest that changing INamagnitude produces corresponding changes in AP amplitude and that KNachannels increase AP energy efficiency (10–30% less Na+influx/AP) over model cells with only voltage-gated K+channels. These findings suggest the possibility that E. virescens reduces the energetic demands of high-frequency APs through rapidly recovering Na+channels and the novel use of KNachannels to maximize AP amplitude at a given Na+conductance.

scholarly journals Processing of ARIA and release from isolated nerve terminals

1999 ◽  
Vol 354 (1381) ◽  
pp. 411-416 ◽  
Author(s):  
Bomie Han ◽  
Gerald D. Fischbach
Keyword(s):  
Neuromuscular Junction ◽  
Action Potential ◽  
Acetylcholine Receptors ◽  
Molecular Layer ◽  
Postsynaptic Membrane ◽  
High Density ◽  
Small Contribution ◽  
Presynaptic Nerve Terminal ◽  
Voltage Gated

The neuromuscular junction is a specialized synapse in that every action potential in the presynaptic nerve terminal results in an action potential in the postsynaptic membrane, unlike most interneuronal synapses where a single presynaptic input makes only a small contribution to the population postsynaptic response. The postsynaptic membrane at the neuromuscular junction contains a high density of neurotransmitter (acetylcholine) receptors and a high density of voltage–gated Na + channels. Thus, the large acetylcholine activated current occurs at the same site where the threshold for action potential generation is low. Acetylcholine receptor inducing activity (ARIA), a 42 kD protein, that stimulates synthesis of acetylcholine receptors and voltage–gated Na + channels in cultured myotubes, probably plays the same roles at developing and mature motor endplates in vivo . ARIA is synthesized as part of a larger, transmembrane, precursor protein called proARIA. Delivery of ARIA from motor neuron cell bodies in the spinal cord to the target endplates involves several steps, including proteolytic cleavage of proARIA. ARIA is also expressed in the central nervous system and it is abundant in the molecular layer of the cerebellum. In this paper we describe our first experiments on the processing and release of ARIA from subcellular fractions containing synaptosomes from the chick cerebellum as a model system.

Undergraduate performance assessment

2017 ◽  
Vol 5 (9) ◽  
pp. 1-7
Author(s):  
Umayya Musharrafieh ◽  
Khalil Ashkar ◽  
Dima Dandashi ◽  
Maya Romani ◽  
Rana Houry ◽  
...  
Keyword(s):  
Medical Students ◽  
Family Medicine ◽  
Assessment Tool ◽  
Clinical Skills ◽  
Faculty Evaluation ◽  
Multiple Choice Questions ◽  
Final Exam ◽  
Monthly Basis ◽  
Medicine Clerkship ◽  
Clinical Evaluations

Introduction: Objective Structured Clinical Examination (OSCE) is considered a useful method of assessing clinical skills besides Multiple Choice Questions (MCQs) and clinical evaluations. Aim: To explore the acceptance of medical students to this assessment tool in medical education and to determine whether the assessment results of MCQs and faculty clinical evaluations agree with the respective OSCE scores of 4th year medical students (Med IV). Methods: performance of a total of 223 Med IV students distributed on academic years 2006-2007, 2007-2008, and 2008-2009 in OSCE, MCQs and faculty evaluations were compared. Out of the total 93 students were asked randomly to fill a questionnaire about their attitudes and acceptance of this tool. The OSCE was conducted every two months for two different groups of medical students who had completed their family medicine rotation, while faculty evaluation based on observation by assessors was submitted on a monthly basis upon the completion of the rotation. The final exam for the family medicine clerkship was performed at the end of the 4thacademic year, and it consisted of MCQsResults: Students highly commended the OSCE as a tool of evaluation by faculty members as it provides a true measure of required clinical skills and communication skills compared to MCQs and faculty evaluation. The study showed a significant positive correlation between the OSCE scores and the clinical evaluation scores while there was no association between the OSCE score and the final exam scores.Conclusion: Student showed high appreciation and acceptance of this type of clinical skills testing. Despite the fact that OSCEs make them more stressed than other modalities of assessment, it remained the preferred one.

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