Metabolic mapping of the primary visual system of the monkey by means of the autoradiographic [14C]deoxyglucose technique.

Abstract

ABSTRACT[14C]deoxyglucose-6-phosphate, the fractional turnover rate of the free [14C]deoxyglucose pool in the tissue, and the ratios of the Michaelis-Menten kinetic constants of hexokinase for deoxyglucose and glucose (6). The key to the localization possible with the method is a quantitative autoradiographic technique for the measurement of local tissue concentrations of ['4C]deoxyglucose-6-phosphate. Even without the quantification, however, the autoradiographs are themselves pictorial representations of the local rates of glucose consumption throughout the brain. Inasmuch as local energy metabolism in the brain, as in other tissues, is closely coupled to'local functional activity, the method has proved effective for the delineation of local cerebral regions with altered functional activity in response to experimentally modified physiological states (7).The binocular visual system of the monkey appeared to offer an appropriately intricate METHODSRhesus monkeys of either sex weighing 2.5-3.5 kg were used in these studies. Polyethylene catheters were inserted in a femoral artery and vein after light halothane and nitrous oxide anesthesia, and the animals were then placed in a restraining chair and allowed to recover from the anesthesia for at least 4 hr. The experimental period was initiated by the intravenous injection of a pulse of 100 ,uCi/kg of ['4C]deoxyglucose (specific activity, 50-55 mCi/mmol; New England Nuclear Corp., Boston, Mass.) contained in 3 ml of normal saline. In most of the animals, timed arterial blood samples were drawn during the ensuing 45 min period for the measurement of the arterial 4230

Brain aerobic glycolysis and motor adaptation learning

“…Surprisingly however, the increase in AG observed here in BA44 is not driven only by increased glucose consumption, but also by reduced oxygen consumption. Oxygen consumption is a direct measure of brain energy consumption (37), and its reduction, combined with the localized reduction in resting-state functional connectivity between BA44 and V1, is indicative of decreased synaptic activity in BA44 (75)(76)(77). The changes in glucose, oxygen, and functional connectivity suggest that both LTP and LTD may have occurred, with the net effect being an overall decrease in the number of synapses (78,79).…”

Metabolic Activation Pattern of Distinct Hippocampal Subregions during Spatial Learning and Memory Retrieval

“…Recent advances in our understanding of its cellular and molecular bases suggest that the glucose utilization signal is a faithful (although indirect) reflection of glutamatemediated synaptic activity (Bonvento et al, 2002;Pellerin and Magistretti, 1994). Over the years, the technique has been extensively used to unravel the involvement of specific brain areas in several paradigms involving somatosensory activation through various modalities (Coopersmith and Leon, 1984;Kennedy et al, 1976;Melzer et al, 1985;Schwartz et al, 1979). Furthermore, it has been applied to obtain functional maps of learningrelated activity such as in Pavlovian conditioning (Jones and Gonzalez-Lima, 2001), habituation (Gonzalez-Lima et al, 1989;Toga and Collins, 1981), or different working memory tasks (Friedman and Goldman-Rakic, 1988;Sybirska et al, 2000).…”

Long-range dichoptic interactions in the human visual cortex in the region corresponding to the blind spot

“…This belief is based on 2-deoxyglucose experiments conducted on monkeys (Kennedy, Des Rosiers, Jehle, Reivich, Sharpe & Sokoloff, 1975;Kennedy, des Rosiers, Sakurada, Shinohara, Reivich, Jehle & Sokoloff, 1976;Horton, 1984;LeVay, Connolly, Houde & Van Essen, 1985). The blind spot is represented as a disk in the striate cortex, driven entirely by the ipsilateral eye and devoid of ocular dominance columns.…”