Astrocyte-Neuron Lactate Shuttle and Hemodynamic Brain Scans Essay

Astrocyte-Neuron Lactate Shuttle and Hemodynamic Brain ScansHemodynamic brain scans such as Positron Emission Tomography (PET) and functional Magnetic Resonance Imaging (fMRI) pitch been of immense utility in the neuroscience fields in illuminating the components and modulation of brain function. However, these hemodynamic brain scans have afforded utility without brain scientists truly understanding the mechanics by which they produce signals. Previously, it had been accepted without verification that the images produced by such techniques were direct results of neuronal exertion. However, new techniques in studying brain function have revealed that when astrocyte activity is inhibited, hemodependent brain scans do not function (Halber 2008). Additionally, other studies have demonstrated that astrocytes display finely tuned responses to stimuli (Halber 2008) which are amenable to communication with from each one other in networks via calcium-wave propagation. In light of the se new findings in regards to astrocyte function and communication, their influence on hemodynamic brain scans would offer much lucidity to our current understanding of neuropathology and neuromodulation. General Findings of astrocytic Influence on Brain ScansBoth PET and fMRI scans are hemodependent brain scans. However, the mechanism by which each works do differ from each other by which fundamental principle of blood flow they measure. In fMRI, a BOLD-signal (blood-oxygen-level-dependent) measurement is utilized which is then translated into working images. PET scans require a radioactive labeled tracer which accumulates in areas of activation. These active areas are then expressed in imaging techniques that interpret the level of activation. However,... ...arch 2009. doi10.1016/j.tins.2008.11.005Mo. (2008, June 20). Starring mathematical function in the brain for astrocytes Web log post. Retrieved from http//scienceblogs.com/neurophilosophy/2008/06/astrocytes_starring_role _in_the_brain.phpSchummers, J., Yu, H., & Sur, M. (2008). Tuned responses of astrocytes and their influence on hemodynamic signals in the visual cortex. Science, 320, 1638-1643. doi 10.1126/science.1156120Segelken, R. (2004). CU laser microscopy technique settles brain chemistry debate, could aid studies of Alzheimers, slam damage. Cornell Chronicle. Retrieved from http//www.news.cornell.edu/chronicle/04/7.1.04/astrocyte-neuron.htmlVaishnavi S.N., Vlassenko A.G., Rundle M.M., Snyder A.Z., Mintun M.A., Raichle, M.E.,(2010). Regional aerobic glycolysis in the human brain. Proc. Natl. Acad. Sci. U SA. 107, 1775717762. doi 10.1073/pnas.1010459107