Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Email this article to a Colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to My Articles & Searches Download to citation manager Citing Articles via HighWire Citing Articles via Google Scholar Articles by Shulman, R. G. Search for Related Content PubMed Citation Articles by Shulman, R. G. Neurophysiology Neurotransmitters General Topics in Psychiatry fMR PET Other Neuroimaging

Functional Imaging Studies: Linking Mind and Basic Neuroscience

OBJECTIVE: The imaging of brain activity with positron emission tomography (PET) and functional magnetic resonance imaging has assumed a central position in psychiatry. Functional imaging signals arise from changes in the neurophysiological parameters of glucose and oxygen consumption mediated by blood flow. METHOD: Recent in vivo ¹³C nuclear magnetic resonance (NMR) neurochemical studies have established a quantitative coupling between the rates of glucose oxidation and glutamate neurotransmitter flux in rats and humans, thereby linking measured neurophysiological parameters to brain function. RESULTS: These results show that in the awake, resting, and unstimulated states, 70%–80% of brain energy consumption is devoted to the same glutamate/glutamine neurotransmitter signaling as are the small percentages stimulated by tasks. Furthermore, in anesthetized animals, in which unstimulated activity is reduced, the total signal rather than a particular increment is required for a response. CONCLUSIONS: On this basis, the total signal, as well as the difference in the signal, measures cortical neurotransmitter flux. The total signal in a region therefore contains valuable information about required brain activity. Although signal change is often more easily measured, certain PET and ¹³C NMR methods can quantify total regional signal activity and thereby provide another measure of neurotransmitter activity.

This article has been cited by other articles:

				L. S. Kegeles, K. M. Malone, M. Slifstein, S. P. Ellis, E. Xanthopoulos, J. G. Keilp, C. Campbell, M. Oquendo, R. L. Van Heertum, and J. J. Mann Response of Cortical Metabolic Deficits to Serotonergic Challenge in Familial Mood Disorders Am J Psychiatry, January 1, 2003; 160(1): 76 - 82. [Abstract] [Full Text] [PDF]

				F. Hyder, D. L. Rothman, and R. G. Shulman From the Cover: Total neuroenergetics support localized brain activity: Implications for the interpretation of fMRI PNAS, August 6, 2002; 99(16): 10771 - 10776. [Abstract] [Full Text] [PDF]

				R. M. GOSSART "Mind" and "Brain". Am J Psychiatry, November 1, 2001; 158(11): 1938 - 1939. [Full Text]

				R. G. Shulman, F. Hyder, and D. L. Rothman Cerebral energetics and the glycogen shunt: Neurochemical basis of functional imaging PNAS, May 3, 2001; (2001) 101129298. [Abstract] [Full Text]

				R. G. Shulman, F. Hyder, and D. L. Rothman Cerebral energetics and the glycogen shunt: Neurochemical basis of functional imaging PNAS, May 22, 2001; 98(11): 6417 - 6422. [Abstract] [Full Text] [PDF]

Get information about faster international access.

Privacy Policy

Copyright © 2001 American Psychiatric Association. All rights reserved.

Home | Search | Current Issue | Past Issues | Subscribe | All APPI Journals | Help | Contact Us