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 structural Magnetic Resonance Imaging (fMRI) have been of immense gain 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 mechanism by which they produce signals. Previously, it had been accepted without verification that the images produced by such techniques were direct results of neuronal activity. However, new techniques in canvas 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 consonant to communication with distributively other in networks via calcium-wave propagation. In light of thes e new findings in regards to astrocyte function and communication, their influence on hemodynamic brain scans would offer much limpidity 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 thusly 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 fork out the level of activation. However,... ...arch 2009. doi10.1016/j.tins.2008.11.005Mo. (2008, June 20). Starring role in the brain for astrocytes Web log post. Retrieved from http//scienceblogs.com/neurophilosophy/2008/06/astrocytes_starring_role_in_the_brain.p hpSchummers, 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, stroke 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