Brain energy metabolism in early blind subjects: neural activity in the visual cortex.
As an attempt to better understand the metabolic basis for the previously reported increases in glucose metabolism in the visual cortex of congenitally blind subjects, cerebral blood flow, oxygen consumption and glucose utilization were investigated with multitracer positron emission tomography. Measurements were carried out in three subjects who became blind early in life and in three age-matched blindfolded controls. Regional analysis of cerebral blood flow, metabolic rates for oxygen and glucose utilization revealed that these parameters were relatively higher in the visual cortex in case of early blindness (109.7 +/- 2.4%; 114.3 +/- 1.5%; 118.0 +/- 5.5%, respectively) than in controls (98.1 +/- 3.9%; 108.6 +/- 3.6%; 105.2 +/- 4.8%). There were slight differences, albeit statistically not significant, between early blind and control subjects in terms of oxygen-to-glucose metabolic ratios. The relatively preserved stoichiometry in the visual areas of blind subjects points to the lack of variation in the yield of glucose oxidation in this cortex. Those observations suggest that the high level of energy metabolism disclosed in early blind visual cortex is related to neural activity.
De Volder
A G
AG
Positron Tomography Laboratory, University of Louvain, Louvain-la-Neuve, Belgium.
Bol
A
A
Blin
J
J
Robert
A
A
Arno
P
P
Grandin
C
C
Michel
C
C
Veraart
C
C
D000328:Adult; D000704:Analysis of Variance; D001345:Autoradiography; D001766:Blindness / Q000151:congenital / Q000378:metabolism* / Q000503:physiopathology; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000378:metabolism*; D002250:Carbon Radioisotopes; D002560:Cerebrovascular Circulation; D004734:Energy Metabolism; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000378:metabolism* / Q000502:physiology; D009928:Organ Specificity; D010101:Oxygen Consumption; D012016:Reference Values; D012039:Regional Blood Flow; D014055:Tomography, Emission-Computed; D014793:Visual Cortex / Q000098:blood supply* / Q000378:metabolism*
D002250:Carbon Radioisotopes