scholarly journals Understanding the Role of Diffusion in Synaptic Transmission through Inquiry-Based Learning & Quantitative Reasoning

2019 ◽  
Vol 81 (6) ◽  
pp. 435-441
Author(s):  
Günther K. H. Zupanc
Keyword(s):  
Synaptic Transmission ◽  
Synaptic Cleft ◽  
Quantitative Reasoning ◽  
Synaptic Delay ◽  
Structural Components ◽  
High Concentration ◽  
Undergraduate Biology ◽  
Inquiry Based Learning ◽  
History Of

The elucidation of the principal features of chemical synaptic transmission has been one of the great achievements in the history of neuroscience, yet students have significant difficulties developing a deeper understanding of the underlying concept. This is particularly true for the role that diffusion of neurotransmitters across the synaptic cleft plays in this process. At least part of the learning problem is due to an erroneous view of diffusion as a slow process, and to an inability to apply the concepts of size and scale to the synapse and its structural components. To overcome these difficulties, a structured/guided inquiry activity, combined with quantitative reasoning tasks, is described for teaching chemical synaptic transmission as part of undergraduate biology or neuroscience courses. Through this activity, students familiarize themselves with the absolute and relative dimensions of the structural components of synapses; use data from morphometric and schematic models of synapses to estimate the time it takes a neurotransmitter to diffuse across the synaptic cleft; and evaluate how this process relates to synaptic delay and generation of a sufficiently high concentration of transmitter molecules for activation of postsynaptic receptors.

Functional Role of Ca2+ Currents in Graded and Spike-Mediated Synaptic Transmission Between Leech Heart Interneurons

1997 ◽  
Vol 77 (4) ◽  
pp. 1779-1794 ◽  
Author(s):  
Jin Lu ◽  
John F. Dalton ◽  
Darrell R. Stokes ◽  
Ronald L. Calabrese
Keyword(s):  
Synaptic Transmission ◽  
Voltage Clamp ◽  
Functional Role ◽  
Inactivation Kinetics ◽  
High Concentration ◽  
Outward Currents ◽  
Low Concentrations ◽  
Low Threshold ◽  
Kinetics Of

Lu, Jin, John F. Dalton, IV, Darrell R. Stokes, and Ronald L. Calabrese. Functional role of Ca2+ currents in graded and spike-mediated synaptic trnasmission between leech heart interneurons. J. Neurophysiol. 77: 1779–1794, 1997. We used intracellular recording and single electrode voltage-clamp techniques to explore Ca2+ currents and their relation to graded and spike-mediated synaptic transmissions in leech heart interneurons. Low-threshold Ca2+ currents (activation begins below −50 mV) consist of a rapidly inactivating component ( I CaF) and a slowly inactivating component ( I CaS). The apparent inactivation kinetics of I CaF appears to be influenced by Ca2+; both the substitution of Ca2+ (5 mM) with Ba2+ (5 mM) in the saline and the intracellular injection of the rapid Ca2+ chelator, bis-( o-aminophenoxy)- N,N,N′,N′-tetraacetic acid (BAPTA), from the recording microelectrode, significantly increase its apparent inactivation time constant. The use of saline with a high concentration of Ba2+ (37.5 mM) permitted exploration of divalent ion currents over a broader activation range, by acting as an effective charge carrier and significantly blocking outward currents. Ramp and pulse voltage-clamp protocols both reveal a rapidly activating and inactivating Ba2+ current ( I BaF) and a less rapidly activating and slowly inactivating Ba2+ current with a broad activation range ( I BaS). Low concentrations of Cd2+ (100–150 μM) selectively block I BaS, without significantly diminishing I BaF. The current that remains in Cd2+ lacks the characteristic delayed activation peak of I BaS and inactivates with two distinct time constants. I BaF appears to correspond to a combination of I CaF and I CaS, i.e., to low-threshold Ca2+ currents, that can be described as T-like. I BaS appears to correspond to a Ca2+ current with a broad activation range, which can be described as L-like. Cd2+ (100 μM) selectively blocks spike-mediated synaptic transmission between heart interneurons without significantly interfering with low-threshold Ca2+ currents and plateau formation in or graded synaptic transmission between heart interneurons. Blockade of spike-mediated synaptic transmission between reciprocally inhibitory heart interneurons with Cd2+ (150 μM), in otherwise normal saline, prevents the expression of normal oscillations (during which activity in the two neurons consists of alternating bursts), so that the neurons fire tonically. We conclude that graded and spike-mediated synaptic transmission may be relatively independent processes in heart interneurons that are controlled predominantly by different Ca2+ currents. Moreover, spike-mediated synaptic inhibition appears to be required for normal oscillation in these neurons.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

The role of a family history of adenocarcinomas in patients with Barrett oesophagus

2001 ◽  
Vol 120 (5) ◽  
pp. A442-A442
Author(s):  
P TSIBOURIS ◽  
M HENDRICKSE ◽  
P ISAACS
Keyword(s):  
Family History ◽  
History Of ◽  
Barrett Oesophagus

Protective Factors and Suicidality in Members of Arab Kindred

Crisis ◽  
2012 ◽  
Vol 33 (2) ◽  
pp. 80-86 ◽  
Author(s):  
Sami Hamdan ◽  
Nadine Melhem ◽  
Israel Orbach ◽  
Ilana Farbstein ◽  
Mohammad El-Haib ◽  
...  
Keyword(s):  
Risk Factors ◽  
Protective Factors ◽  
Suicidal Behavior ◽  
Composite International Diagnostic Interview ◽  
Diagnostic Interview ◽  
Suicidal Risk ◽  
Arab Population ◽  
Psychiatric Interview ◽  
History Of

Background: Relatively little is known about the role of protective factors in an Arab population in the presence of suicidal risk factors. Aims: To examine the role of protective factors in a subsample of in large Arab Kindred participants in the presence of suicidal risk factors. Methods: We assessed protective and risk factors in a sample of 64 participants (16 suicidal and 48 nonsuicidal) between 15 and 55 years of age, using a comprehensive structured psychiatric interview, the Composite International Diagnostic Interview (CIDI), self-reported depression, anxiety, hopelessness, impulsivity, hostility, and suicidal behavior in first-degree and second-relatives. We also used the Religiosity Questionnaire and suicide attitude (SUIATT) and multidimensional perceived support scale. Results: Suicidal as opposed to nonsuicidal participants were more likely to have a lifetime history of major depressive disorder (MDD) (68.8% vs. 22.9% χ2 = 11.17, p = .001), an anxiety disorder (87.5% vs. 22.9, χ2 = 21.02, p < .001), or posttraumatic stress disorder (PTSD) (25% vs. 0.0%, Fisher’s, p = .003). Individuals who are otherwise at high risk for suicidality have a much lower risk when they experience higher perceived social support (3.31 ± 1.36 vs. 4.96 ± 1.40, t = 4.10, df = 62, p < .001), and they have the view that suicide is somehow unacceptable (1.83 ± .10 vs. 1.89 ± .07, t = 2.76, df = 60, p = .008). Conclusions: Taken together with other studies, these data suggest that the augmentation of protective factors could play a very important role in the prevention of incidental and recurrent suicidal behavior in Arab populations, where suicidal behavior in increasing rapidly.

THE ROLE OF RECTAL EUS-FNA/B IN PRE-SACRAL UNDEFINED LESIONS IN PATIENTS WITH HISTORY OF LOWER GI NEOPLASIA

2020 ◽  
Author(s):  
B Mangiavillano ◽  
S Carrara ◽  
E Dabizzi ◽  
F Auriemma ◽  
V Cennamo ◽  
...  
Keyword(s):  
History Of

The problem of periodization of the history of religion

1997 ◽  
pp. 3-8
Author(s):  
Borys Lobovyk
Keyword(s):  
Religious Studies ◽  
Human Being ◽  
Religious Development ◽  
History Of Religion ◽  
The Social ◽  
The World ◽  
History Of ◽  
Role Of Religion

An important problem of religious studies, the history of religion as a branch of knowledge is the periodization process of the development of religious phenomenon. It is precisely here, as in focus, that the question of the essence and meaning of the religious development of the human being of the world, the origin of beliefs and cult, the reasons for the changes in them, the place and role of religion in the social and spiritual process, etc., are converging.

ROLE OF LIPID PROFILE IN OVARIAN CARCINOMA PATIENTS

2019 ◽  
Vol 3 (8) ◽  
Author(s):  
Dr. Manisha ◽  
Dr. Ruchi Jindal
Keyword(s):  
Ovarian Cancer ◽  
Lipid Profile ◽  
Cancer Patients ◽  
Ovarian Tumor ◽  
Ovarian Cancer Risk ◽  
Low Level ◽  
Medical College ◽  
Group I ◽  
History Of

Background: The term "ovarian cancer" includes several different types of cancer that  arise from cells of the ovary, most commonly, tumors arise from the epithelium or lining cells of the ovary.  Ovarian cancer risk is positively associated with higher consumption of dietary cholesterol and eggs, and inversely associated with a higher intake of vegetables. High consumption of fats may increase circulating estrogen levels, thus increasing the possibility of cell damage and proliferation that is responsible for cancerous growth. Material & Methods: The present study was conducted at Geetanjali Medical College and Hospital, Udaipur (Rajasthan). Total  100 cases (females) attending the obstetrics and gynecology department for some gynecological and other problem  were selected for this study between the age of 40-60 years, who were attending cancer centre at GEETANJALI MEDICAL COLLEGE AND  HOSPITAL, Udaipur (Rajasthan).                GROUP I: - It consisted of healthy females control subjects (n=50) .By routine examination and tests, we ensured that all the subjects were healthy and there were no signs and symptoms or history of ovarian tumor and diseases GROUP II: - It consisted of ovarian cancer females subjects (n=50) with a history of ovarian tumor. Results:   Higher level of cholesterol, LDL, VLDL and low level of HDL are found in ovarian cancer patients. Conclusion: The present study we highlights the importance and role of serum lipid profile in diagnosis, prognosis and recurrence of the disease. The study shows that serum level of cholesterol, LDL, VLDL was elevated in  patients of ovarian cancer while low level of HDL are found in ovarian cancer patients. Key words: lipid profile, ovarian cancer.

PERAN IBU DALAM PENINGKATAN SISTEM IMUN ANAK DENGAN INFEKSI SALURAN PERNAFASAN AKUT

2019 ◽  
Vol 11 (2) ◽  
pp. 79-86
Author(s):  
Cindy Ayustin Noya ◽  
Angkit Kinasih ◽  
Venti Agustina ◽  
R.Rr Maria Dyah Kurniasari
Keyword(s):  
Immune System ◽  
Acute Respiratory Infection ◽  
Lower Respiratory Tract ◽  
Research Method ◽  
Respiratory Infections ◽  
Acute Respiratory Infections ◽  
Clean Environment ◽  
History Of ◽  
Qualitative Descriptive

Infeksi saluran pernafasan akut atau yang sering disebut ISPA merupakan infeksi pada saluran pernafasan baik saluran pernafasan atas atau bawah.ISPA juga kebanyakan terjadi pada anak balita karena daya tahan tubuh mereka tidak kuat dalam menghadapi penyakit ISPA. ISPA mengakibatkan kematiansekitar15%-20% per tahun pada usia balita di Negara berkembang. Tujuan penelitian ini adalah untuk mengetahui dan menganalisa peran ibu dalam meningkatkan sistem imun anak dengan ISPA.Metode penelitian yang digunakan dalam penelitian ini adalah kualitatif deskriptif dengan sampel purposive sampling.Populasi dan sampel penelitian ini adalah ibu yang mempunyai anak dengan riwayat dan saat ini menderita penyakit ISPA di Batu Gajah Kota Ambon.Partisipan dalam penelitian ini berjumlah 5 orang. Hasil dari penelitian mendapati 4 kategori yaitu pemberian nutrisi pada anak untuk memenuhi kebutuhan agar sistem imunnya terjaga, kebersihan lingkungan, peran ibu dalam melakukan pencegahan pada anaknya yang mengalami ISPA, dan  peran ibu dalam menjaga dan mempertahankan kesehatan anaknya.   Kata kunci: peran ibu, sistem imun, ispa THE ROLE OF MOTHERS IN INCREASING IMMUNE SYSTEM OF CHILDREN WITH ACUTE RESPIRATORY INFECTION    ABSTRACT Acute respiratory infections or often called ARI is an infection of the upper or lower respiratory tract. ARI occurs mostly in children under the age of five because their endurance is not strong in dealing with ARI. ARI results in deaths of around 15%-20% per year at the age of under-five in developing countries. The purpose of this study was to determine and analyze the role of mothers in improving the immune system of children against ARI. The research method used in this study was qualitative descriptive with a purposive sampling sample. Respondents and samples of this study were five mothers who had children with a history of ARI and currently suffering from the disease in Batu Gajah, Ambon City. The results of the study found 4 categories, namely providing nutrition to children to meet their needs so that their immune systems are maintained, clean environment, mother's role in preventing children with ARI, and mother's role to preserve and maintain the health of their children. The findings indicated that in terms of coping or improving the immune system of a child to avoid ARI, it is necessary to have role the of mothers in providing nutrition so that the immune system is boosted, besides that the mother can prevent and protect her child from various diseases, especially ARI. Keywords: role of mothers, immune system, acute respiratory infections

Sign in / Sign up

Export Citation Format

Share Document