scholarly journals Portable conduction velocity experiments using earthworms for the college and high school neuroscience teaching laboratory

2014 ◽  
Vol 38 (1) ◽  
pp. 62-70 ◽  
Author(s):  
Kyle M. Shannon ◽  
Gregory J. Gage ◽  
Aleksandra Jankovic ◽  
W. Jeffrey Wilson ◽  
Timothy C. Marzullo
Keyword(s):  
High School ◽  
Conduction Velocity ◽  
Classroom Environment ◽  
Action Potentials ◽  
Low Cost ◽  
Electrode Placement ◽  
Giant Fiber ◽  
Velocity Measurements ◽  
Single Action ◽  
Tactile Stimuli

The earthworm is ideal for studying action potential conduction velocity in a classroom setting, as its simple linear anatomy allows easy axon length measurements and the worm's sparse coding allows single action potentials to be easily identified. The earthworm has two giant fiber systems (lateral and medial) with different conduction velocities that can be easily measured by manipulating electrode placement and the tactile stimulus. Here, we present a portable and robust experimental setup that allows students to perform conduction velocity measurements within a 30-min to 1-h laboratory session. Our improvement over this well-known preparation is the combination of behaviorally relevant tactile stimuli (avoiding electrical stimulation) with the invention of minimal, low-cost, and portable equipment. We tested these experiments during workshops in both a high school and college classroom environment and found positive learning outcomes when we compared pre- and posttests taken by the students.

scholarly journals Electroneurography of the ulnar nerve in dogs

2014 ◽  
Vol 83 (4) ◽  
pp. 405-409 ◽  
Author(s):  
Ivo Hájek ◽  
Pavel Schánilec ◽  
Ivana Uhríková ◽  
Martin Pyszko ◽  
Jaroslav Dufek
Keyword(s):  
Action Potential ◽  
Ulnar Nerve ◽  
Conduction Velocity ◽  
Rectal Temperature ◽  
Action Potentials ◽  
Limb Length ◽  
Muscle Action ◽  
Velocity Measurements ◽  
Healthy Dogs ◽  
Stimulating Electrodes

Electroneurography as one of the electrodiagnostic techniques is used to measure the speed of action potential which is propagated down the nerve after stimulation. It gives information about normal functioning of the peripheral nerves. The aim of this study was to evaluate the applicability of a new electroneurographic technique by performing motor nerve conduction velocity measurements in the ulnar nerve with surface stimulating electrodes in healthy dogs, to correlate the obtained data by age, limb length, rectal temperature, and sex; and to compare these results with published findings utilizing needle stimulating electrodes. The study was performed in 24 clinically healthy dogs without anaesthesia. Rectal temperatures and limb lengths were measured in all individuals. There were significant correlations among several indicators (age, rectal temperature, limb length, conduction velocity, latency and duration of compound muscle action potentials). Limb length was found to have a significant effect on the duration of the compound muscle action potential from both stimulation sites (proximal/distal; r = 0.71, r = 0.68, P < 0.01), but there was no effect on the conduction velocity or amplitude of the action potentials. There was no significant difference (P > 0.05) in the measured indicators between males and females, even though females had a higher mean conduction velocity than males. These results prove that conduction velocity measurements in dogs could be performed non-invasively, without a danger of infection or haematomas or complications with anaesthesia, which is more favourable and time-saving for clinical practice, and more comfortable for patients.

The Iterative Development and Testing of an Interactive Mobile Application for Skill Retention of Cardiopulmonary Resuscitation Among High School Students: A Pilot Study

2021 ◽  
pp. 104687812110326
Author(s):  
Adeel Arif ◽  
Amber Arif ◽  
Kimberly Anne Fasciglione ◽  
Farrukh Nadeem Jafri
Keyword(s):  
High School ◽  
High School Students ◽  
Cardiopulmonary Resuscitation ◽  
Mobile Apps ◽  
Low Cost ◽  
Survival Rates ◽  
Compression Rate ◽  
School Students ◽  
Skill Retention ◽  
Before And After

Abstract: Background Locations concentrated with High School (HS) students tend to have lower out-of-hospital cardiac arrest (OHCA) survival rates. Mobile applications (apps) have the capability to augment cardiopulmonary resuscitation (CPR) skill retention as a low-cost, accessible training method. Methods An iterative process to develop an app to reinforce CPR skills emphasizing hand placement, compression rate, real-time feedback, and recurring tips is described. The app was tested on HS students to measure its impact on quality and comfort of CPR using Likert surveys and skills assessments before and after one month of usage. CPR Score and compression rate were measured using the Laerdal™ Little Anne Manikin QCPR software. Results Fourteen HS students participated in a prospective observational study. It was found that the use of the developed app was associated with improved CPR performance (80.43% v. 87.86%, p=0.01-0.02, 95% CI=2.20-12.66) after one month. Additionally, improvements were demonstrated in compression rate accuracy (21.43% v. 64.29%, p=0.041, 95% CI=0.132-0.725), increased comfort performing CPR (3.86 v. 4.79, p<0.001, 95% CI =0.99-1.00) and comfort performing CPR on strangers (2.71 v. 4.42, p<0.001, 95% CI=1.24-2.19). In addition, for every time the app was used, CPR performance increased by 0.5668% (p=0.0182). Conclusion Findings suggest that mobile apps may have promising implications as augmentative tools for CPR curriculums.

Calcium Dynamics and Compartmentalization in Leech Neurons

2005 ◽  
Vol 94 (6) ◽  
pp. 4430-4440 ◽  
Author(s):  
Sofija Andjelic ◽  
Vincent Torre
Keyword(s):  
Information Processing ◽  
Action Potential ◽  
Action Potentials ◽  
Time Course ◽  
Ccd Camera ◽  
Calcium Dynamics ◽  
Single Action ◽  
Single Action Potential ◽  
Calcium Indicator ◽  
Mechanosensory Neurons

Calcium dynamics in leech neurons were studied using a fast CCD camera. Fluorescence changes (Δ F/ F) of the membrane impermeable calcium indicator Oregon Green were measured. The dye was pressure injected into the soma of neurons under investigation. Δ F/ F caused by a single action potential (AP) in mechanosensory neurons had approximately the same amplitude and time course in the soma and in distal processes. By contrast, in other neurons such as the Anterior Pagoda neuron, the Annulus Erector motoneuron, the L motoneuron, and other motoneurons, APs evoked by passing depolarizing current in the soma produced much larger fluorescence changes in distal processes than in the soma. When APs were evoked by stimulating one distal axon through the root, Δ F/ F was large in all distal processes but very small in the soma. Our results show a clear compartmentalization of calcium dynamics in most leech neurons in which the soma does not give propagating action potentials. In such cells, the soma, while not excitable, can affect information processing by modulating the sites of origin and conduction of AP propagation in distal excitable processes.

Electronmicroscopic and electrophysiological studies of the teat branch of the XIII thoracic nerve: relationship with lactation in the rat

1988 ◽  
Vol 118 (3) ◽  
pp. 471-483 ◽  
Author(s):  
L. M. Voloschin ◽  
E. Décima ◽  
J. H. Tramezzani
Keyword(s):  
Electrical Stimulation ◽  
Conduction Velocity ◽  
Action Potentials ◽  
Silent Period ◽  
High Amplitude ◽  
Milk Ejection ◽  
Nerve Activity ◽  
Thoracic Nerve ◽  
Myelinated Fibres ◽  
Stimulation Of

ABSTRACT Electrical stimulation of the XIII thoracic nerve (the 'mammary nerve') causes milk ejection and the release of prolactin and other hormones. We have analysed the route of the suckling stimulus at the level of different subgroups of fibres of the teat branch of the XIII thoracic nerve (TBTN), which innervates the nipple and surrounding skin, and assessed the micromorphology of the TBTN in relation to lactation. There were 844 ± 63 and 868 ± 141 (s.e.m.) nerve fibres in the TBTN (85% non-myelinated) in virgin and lactating rats respectively. Non-myelinated fibres were enlarged in lactating rats; the modal value being 0·3–0·4 μm2 for virgin and 0·4–0·5 μm2 for lactating rats (P > 0·001; Kolmogorov–Smirnov test). The modal value for myelinated fibres was 3–6 μm2 in both groups. The compound action potential of the TBTN in response to electrical stimulation showed two early volleys produced by the Aα- and Aδ-subgroups of myelinated fibres (conduction velocity rate of 60 and 14 m/s respectively), and a late third volley originated in non-myelinated fibres ('C') group; conduction velocity rate 1·4 m/s). Before milk ejection the suckling pups caused 'double bursts' of fibre activity in the Aδ fibres of the TBTN. Each 'double burst' consisted of low amplitude action potentials and comprised two multiple discharges (33–37 ms each) separated by a silent period of around 35 ms. The 'double bursts' occurred at a frequency of 3–4/s, were triggered by the stimulation of the nipple and were related to fast cheek movements visible only by watching the pups closely. In contrast, the Aα fibres of the TBTN showed brief bursts of high amplitude potentials before milk ejection. These were triggered by the stimulation of cutaneous receptors during gross slow sucking motions of the pup (jaw movements). Immediately before the triggering of milk ejection the mother was always asleep and a low nerve activity was recorded in the TBTN at this time. When reflex milk ejection occurred, the mother woke and a brisk increase in nerve activity was detected; this decreased when milk ejection was accomplished. In conscious rats the double-burst type of discharges in Aδ fibres was not observed, possibly because this activity cannot be detected by the recording methods currently employed in conscious animals. During milk ejection, action potentials of high amplitude were conveyed in the Aα fibres of the TBTN. During the treading time of the stretch reaction (SR), a brisk increase in activity occurred in larger fibres; during the stretching periods of the SR a burst-type discharge was again observed in slow-conducting afferents; when the pups changed nipple an abrupt increase in activity occurred in larger fibres. In summary, the non-myelinated fibres of the TBTN are increased in diameter during lactation, and the pattern of suckling-evoked nerve activity in myelinated fibres showed that (a) the double burst of Aδ fibres, produced by individual sucks before milk ejection, could be one of the conditions required for the triggering of the reflex, and (b) the nerve activity displayed during milk-ejection action may result, at least in part, from 'non-specific' stimulation of cutaneous receptors. J. Endocr. (1988) 118, 471–483

Structure and Function of the Lateral Giant Neurone of the Primitive Crustacean Anaspides Tasmaniae

1979 ◽  
Vol 78 (1) ◽  
pp. 121-136
Author(s):  
GERALD E. SILVEY ◽  
IAN S. WILSON
Keyword(s):  
Action Potentials ◽  
Tactile Stimulation ◽  
Large Diameter ◽  
Whole Body ◽  
Giant Fibre ◽  
Single Action ◽  
Giant Neurone ◽  
And Function ◽  
Thoracic And Abdominal ◽  
Stimulation Of

The syncarid crustacean Anaspides tasmaniae rapidly flexes its free thoracic and abdominal segments in response to tactile stimulation of its body. This response decrements but recovers in slightly more than one hour. The fast flexion is evoked by single action potentials in the lateral of two large diameter fibres (40 μm) which lie on either side of the cord. The lateral giant fibre is made up of fused axons of 11 neurones, one in each of the last 5 thoracic and 6 abdominal ganglia. The soma of each neurone lies contralateral to the axon. Its neurite crosses that of its counterpart in the commissure and gives out dendrites into the neuropile of each hemiganglion. The lateral giant neurone receives input from the whole body but fires in response only to input from the fourth thoracic segment posteriorly. Both fibres respond with tactile stimulation of only one side. Since neither current nor action potentials spread from one fibre to the other, afferents must synapse with both giant neurones. The close morphological and physiological similarities of the lateral giant neurone in Anaspides to that in the crayfish (Eucarida) suggest that the lateral giant system arose in the ancestor common to syncarids and eucarids, prior to the Carboniferous.

THE INFLUENCE OF MORAL DISENGAGEMENT ON CLASSROOM ENVIRONMENT IN A JUNIOR HIGH SCHOOLEMENT ON CLASSROOM ENVIRONMENT IN A JUNIOR HIGH SCHOOL

2021 ◽  
pp. 208-216
Author(s):  
Yufiarti ◽  
Thia Rusbita
Keyword(s):  
High School ◽  
Regression Analysis ◽  
Data Analysis ◽  
Junior High School ◽  
Classroom Environment ◽  
Moral Disengagement ◽  
Junior High ◽  
Research Subject ◽  
Analysis Method ◽  
Negative Behaviour

Moral disengagement is a tendency to justify negative behaviour that is morally acceptable and minimizes the influence of others. It is supported by Bandura et al (2000) and Santrock (2003) who said that the teenagers have a tendency to not show their consistent behaviour in different moral situations. This research aimed to find out the influence of moral disengagement on classroom environment in junior high school. The research instruments used were a modified form of Moral Disengagement Instrument (MDI) and What is Happening in This Class? (WIHIC) Questionnaire. The research subject included 171 students of junior high school. The data analysis method used in testing hypothesis was regression analysis. Analysis of the data showed that there was a significant influence of moral disengagement on classroom environment in junior high school. The classroom environment was found to be influenced by moral disengagement .

Electrophysiological properties of neurons within the nucleus ambiguus of adult guinea pigs

1991 ◽  
Vol 66 (3) ◽  
pp. 744-761 ◽  
Author(s):  
S. M. Johnson ◽  
P. A. Getting
Keyword(s):  
Action Potential ◽  
Action Potentials ◽  
Outward Current ◽  
Nucleus Ambiguus ◽  
Transient Outward Current ◽  
Maximum Magnitude ◽  
Action Potential Firing ◽  
Onset Of Action ◽  
Electrophysiological Properties ◽  
Single Action

1. The purpose of this study was to determine the electrophysiological properties of neurons within the region of the nucleus ambiguus (NA), an area that contains the ventral respiratory group. By the use of an in vitro brain stem slice preparation, intracellular recordings from neurons in this region (to be referred to as NA neurons, n = 235) revealed the following properties: postinhibitory rebound (PIR), delayed excitation (DE), adaptation, and posttetanic hyperpolarization (PTH). NA neurons were separated into three groups on the basis of their expression of PIR and DE: PIR cells (58%), DE cells (31%), and Non cells (10%). Non cells expressed neither PIR nor DE and no cells expressed both PIR and DE. 2. PIR was a transient depolarization that produced a single action potential or a burst of action potentials when the cell was released from hyperpolarization. In the presence of tetrodotoxin (TTX), the maximum magnitude of PIR was 7-12 mV. Under voltage-clamp conditions, hyperpolarizing voltage steps elicited a small inward current during the hyperpolarization and a small inward tail current on release from hyperpolarization. These currents, which mediate PIR, were most likely due to Q-current because they were blocked with extracellular cesium and were insensitive to barium. 3. DE was a delay in the onset of action potential firing when cells were hyperpolarized before application of depolarizing current. When cells were hyperpolarized to -90 mV for greater than or equal to 300 ms, maximum delays ranged from 150 to 450 ms. The transient outward current underlying DE was presumed to be A-current because of the current's activation and inactivation characteristics and its elimination by 4-aminopyridine (4-AP). 4. Adaptation was examined by applying depolarizing current for 2.0 s and measuring the frequency of evoked action potentials. Although there was a large degree of variability in the degree of adaptation, PIR cells tended to express less adaptation than DE and Non cells. Nearly three-fourths of all NA neurons adapted rapidly (i.e., 50% adaptation in less than 200 ms), but PIR cells tended to adapt faster than DE and Non cells. PTH after a train of action potentials was relatively rare and occurred more often in DE cells (43%) and Non cells (33%) than in PIR cells (13%). PTH had a magnitude of up to 18 mV and time constants that reflected the presence of one (1.7 +/- 1.4 s, mean +/- SD) or two components (0.28 +/- 0.13 and 4.1 +/- 2.2 s).(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Conduction velocity of the rabbit facial nerve: a noninvasive functional evaluation

2003 ◽  
Vol 17 (2) ◽  
pp. 126-131 ◽  
Author(s):  
Belmiro Cavalcanti do Egito Vasconcelos ◽  
Cosme Gay Escoda ◽  
Ricardo José de Holanda Vasconcellos ◽  
Riedel Frota Sá Nogueira Neves
Keyword(s):  
Facial Nerve ◽  
Conduction Velocity ◽  
Nerve Conduction ◽  
Action Potentials ◽  
Functional Evaluation ◽  
Surface Electrodes ◽  
Nerve Grafts ◽  
Synthetic Materials ◽  
Facial Nerves ◽  
The Mean

The aim of this study was to evaluate standardized conduction velocity data for uninjured facial nerve and facial nerve repaired with autologous graft nerves and synthetic materials. An evaluation was made measuring the preoperative differences in the facial nerve conduction velocities on either side, and ascertaining the existence of a positive correlation between facial nerve conduction velocity and the number of axons regenerated postoperatively. In 17 rabbits, bilateral facial nerve motor action potentials were recorded pre- and postoperatively. The stimulation surface electrodes were placed on the auricular pavilion (facial nerve trunk) and the recording surface electrodes were placed on the quadratus labii inferior muscle. The facial nerves were isolated, transected and separated 10 mm apart. The gap between the two nerve ends was repaired with autologous nerve grafts and PTFE-e (polytetrafluoroethylene) or collagen tubes. The mean of maximal conduction velocity of the facial nerve was 41.10 m/s. After 15 days no nerve conduction was evoked in the evaluated group. For the period of 2 and 4 months the mean conduction velocity was approximately 50% of the normal value in the subgroups assessed. A significant correlation was observed between the conduction velocity and the number of regenerated axons. Noninvasive functional evaluation with surface electrodes can be useful for stimulating and recording muscle action potentials and for assessing the functional state of the facial nerve.

scholarly journals A viabilidade do uso do pêndulo simples como ferramenta no ensino de física do ensino médio para o cálculo da aceleração da gravidade local

2020 ◽  
Vol 42 ◽  
pp. e1
Author(s):  
Cristiano Rocha da Cunha ◽  
Lúcio Ângelo Vidal ◽  
Guilherme Tales da Silva ◽  
Ruth Silva Pereira ◽  
Rita Santana Ramos Silva ◽  
...  
Keyword(s):  
High School ◽  
Learning Process ◽  
Low Cost ◽  
Simple Pendulum ◽  
Oscillatory Movement ◽  
High School Classrooms ◽  
G Value ◽  
Acceleration Of Gravity ◽  
Teaching Learning

Knowing the g-value of acceleration of gravity is of paramount importance in various analyzes, and there are several ways of obtaining it experimentally. Here, searching for resources that are easy to apply in high school classrooms, the authors opted for the observation of a simple pendulum, performing a series of measurements of the pendulum period and applying them to the equations (appropriately manipulated for this experiment) of this oscillatory movement. The experiment was carried out in four steps: one with a mass of 10 grams and three with a mass of 20 grams; two with ten swings, one with fifteen and one with twenty. As a result, four values of local acceleration were estimated,which were compared, using the theory of errors, with the value made available in the literature. With these data, the feasibility of using this device in the teaching-learning process was verified, given its ease of handling and assembly, its low cost and its negligible error with the value of the literature.

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