Question 1
What role does sodium play in neuronal action?
Sodium supports the proper functioning of the nerves by playing its role in action potentials. Action potentials are electrical impulses sent when the nerve cells receive signals down the length of the cells, triggering communication with the neighboring cells. During the action potentials, sodium ions rush out of the nerve cells to initiate electrochemical impulses (Budvytyte et al., 2014).
Why is this approach relevant or useful to understanding the loss of function in neurons?
This approach is useful to understand neurons’ loss of functions because lack of sodium in the blood hinders the communication of the nerves; hence deficiency of sodium can result in muscle cramps because of an abnormal communication between the muscle fibers and the nerves (Budvytyte et al., 2014).
Question 2
What is the normal concentration gradient of sodium in the nervous system (should the sodium concentration be higher or lower within the cell compared to the extracellular fluid)?
For a resting neuron, there is a high concentration of chlorine and sodium ions in the extracellular fluid than in the intracellular fluid. However, there is a high potassium concentration in the intracellular fluids compared to the extracellular fluid (Madelin et al., 2010).
How does the change in the sodium concentration detected from the hippocampus MRI suggest that the hippocampus’s neurons became diseased and were not functioning properly?
To detect neuron death, Sodium MRI imaging is used. The higher sodium (Na+) concentration indicates dead or damaged cells. When making comparisons of the two images of the control patients and the Alzheimer’s brain, brighter areas are seen in the Alzheimer’s patent brain than in the control patient. This is an indication of higher concentration levels of sodium and indicates dysfunction of neurons. Before the death of cells, the increased sodium levels in the tissue could result from direct sodium leak because of the Na/K ATPase retrogradation or amyloid beta channels (Mellon et al., 2009).
What sort of a change in the Na+ concentration gradient would you expect when neurons are damaged or malfunctioning?
Only a small intracellular sodium increase would be expected to produce signal intensity change. After the death of the neurons, the space in the intracellular shrinks, and the extracellular space expands. Moreover, the extracellular space will have a large sodium concentration which produces a large signal intensity of sodium (Mellon et al., 2009).
Question 3
Mellon, E. A., Pilkinton, D. T., Clark, C. M., Elliott, M. A., Witschey, W. R. ., Borthakur, A., & Reddy, R. (January 01, 2009). Sodium MR imaging detection of mild Alzheimer disease: a preliminary study. American Journal of Neuroradiology, 30, 5, 978-84. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2866317/
Budvytyte, R., Gonzalez-Perez, A., Mosgaard, L., & Heimburg, T. (January 01, 2014). Action Potential Collision in Nerves. Biophysical Journal, 106)
Madelin,G, Oesingmann.N, Johnson. N, A. Jerschow, and M. Inglese (2010). Sodium MRI with Triple Quantum Filter and Inversion Recovery at 7T. [ONLINE] Available at: http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCcQFjAA&url=http%3A%2F%2Fwww.med.nyu.edu%2Fradiology_research%2Fassets%2F03251.pdf&ei=tTyNVJmdH9GcugS5lYCIAw&usg=AFQjCNEbJrsrWJx0NrRJ0UjQSQ7y7IPJtA&sig2=4GdWwL6yW-a0Obj6LLMEmA&bvm=bv.81828268,d.c2E.[Last Accessed 14th November 2014].
Question 4
The peer-reviewed article “Sodium MR imaging detection of mild Alzheimer’s disease” discusses how the changes in the concentration of sodium detected from the hippocampus MRI suggest that the hippocampus neuron became diseased and did not function properly.
The article “Action Potential Collision in Nerves” discusses the Potential action Collision in Nerves. I used this assignment’s article to understand the role sodium plays in neuronal action.
The article “Sodium MRI with Triple Quantum Filter and Inversion Recovery at 7T” concerns the current awareness of NNR in medicine. I used the article to understand the differences in the relative concentrations of sodium (Na+) in the hippocampus using magnetic resonance imaging (MRI).
In what ways are the studies similar in their method and conclusions?
All three studies used experimental methodology in their research design. Moreover, their conclusions showed similarities since all of them proved their hypothesis about sodium innerves.
In what ways are the studies different in their method and conclusions?
The three studies used different equipment in their data collection. For instance, the study of “Sodium MR imaging detection of mild Alzheimer’s disease” used a 3T clinical scanner, in the study “Sodium MRI with Triple Quantum Filter and Inversion Recovery at 7T” used a 7T Whole Body Scanner and a single tuned Na head coil.
Question 7
What other observations might we expect to find in cases with similar issues?
The other observations expected to be found using sodium imaging as a clinical tool in detecting neuropathologic changes that are related to Alzheimer’s disease
What would we want to look for in the future, now that we know what this case has taught us?
In the future, we would want to look for the implementation of IR23NaMRI and TQR for the human brain at 7T in vivo to assess the intracellular concentration of sodium.
Question 8
Give your resolution of the case: What does it tell us about autopoiesis in human anatomy and physiology?
I resolve that the case is that there is a dysfunction in the neurons or cell death because of the brighter areas of the patient’s brain. Brighter areas are an indication of higher concentration levels of sodium on the neurons that have dysfunctional.
On a scale of 1–5, rate your confidence in your conclusions in questions 1 and 2.
I would rate my conclusions at 5
Question 9
Describe how you located the information you used in this case.
To begin the search, I started with the most comprehensive database, the Cumulative Index to Nursing and Allied Health (NINAH) (Kennedy 2009). The search then continued to search engines such as British Nursing Index and MEDLINE. Moreover, PubMed and NCBI were other major search engines that assisted some relevant articles. These search engines were used because they contained most peer review articles and books. To limit and narrow down the search for articles, internal searches of the databases were used by inserting the full length of texts and searching the relevant articles from the list of journals displayed. Moreover, I limited myself to the current articles of up to 5 years.
If you had it to do over again, what might you do differently?
I would use different resources to get different information to compare different studies.
References
Budvytyte, R., Gonzalez-Perez, A., Mosgaard, L., & Heimburg, T. (January 01, 2014). Action Potential Collision in Nerves. Biophysical Journal, 106, 2.)
Madelin, N. Oesingmann, G. Johnson, A. Jerschow, and M. Inglese (2010). Sodium MRI with Triple Quantum Filter and Inversion Recovery at 7T. [ONLINE] Available at: http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCcQFjAA&url=http%3A%2F%2Fwww.med.nyu.edu%2Fradiology_research%2Fassets%2F03251.pdf&ei=tTyNVJmdH9GcugS5lYCIAw&usg=AFQjCNEbJrsrWJx0NrRJ0UjQSQ7y7IPJtA&sig2=4GdWwL6yW-a0Obj6LLMEmA&bvm=bv.81828268,d.c2E. [Last Accessed 14th November 2014].
Kennedy, J. R. (2009). Library research guide to education: illustrated search strategy and sources. Ann Arbor, Mich, Pierian Press.
Mellon, E. A., Pilkinton, D. T., Clark, C. M., Elliott, M. A., Witschey, W. R. ., Borthakur, A., & Reddy, R. (January 01, 2009). Sodium MR imaging detection of mild Alzheimer disease: a preliminary study. Ajnr. American Journal of Neuroradiology, 30, 5, 978-84. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2866317/
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