Fig. 2.

¹³C MRS and PET results of baseline energy. (A) Experimental results of V_cyc and CMR_glc(ox),N. Values of V_cyc and CMR_glc(ox),N for the rat brain reported in studies published between 1998 and 2006. The dark blue squares are from Patel et al. (58), the red circle is from Oz et al. (59), the light blue circle is from Choi et al. (60), the green diamonds are from de Graaf et al. (61), and the gray triangles are from Sibson et al. (29). For details of these papers, see ref. 30. [Reproduced with permission from Hyder et al. (30) (Copyright 2006).] (B) The ratio of V_cyc/CMR_glc(ox),N in the nonanesthetized resting awake state in rat (extrapolated from A; see ·) and human brain (see ref. 30 for details). Similarity of the V_cyc/CMR_glc(ox),N ratio in rats and humans suggests that the relationship between V_cyc and CMR_glc(ox),N are similar. [Reproduced with permission from Hyder et al. (30) (Copyright 2006).] (C) PET image of CMR_glc of the human brain showing uniform and high energy metabolism in the resting, awake state. From ref. 32 with permission. [Reprinted by permission from Wolters Kluwer Health: Alkire MT (2008) Loss of effective connectivity during general anesthesia. Int Anesthesiol Clin 46(3):55–73.]