Figure 2. (A) Typical traces show changes in the intensities of fluorescence at 340 (I³⁴⁰) and 380 nm (I³⁸⁰) and their ratio (R340/380) caused by aglycemic anoxia and (B) the inhibitory effects of thiopental on aglycemic anoxia-mediated changes in R340/380 in hippocampal (Hippocampus) and cortical slices (Cortex). The values of I³⁴⁰and I³⁸⁰(arbitrary units) at several time points are given above the I³⁴⁰and I³⁸⁰traces. Aglycemic anoxia is indicated by bars below each trace. The vertical line indicates the normalized increase in R340/380. There are three phases of increases in R340/380 after the onset of 15 min of aglycemic anoxia: a slow increase phase (SP), a rapid increase phase (RP), and a plateau phase (PP). The [Ca²⁺]ⁱplateau indicates the period between the two vertical dotted lines. Thiopental was present 5 min before and during the period of ischemia, as indicated by the bar above each trace.