Biophotonic Activity and Transmission Mediated by Mutual Actions of Neurotransmitters are Involved in the Origin and Altered States of Consciousness

Individual and synergistic effects of different neurotransmitters and propofol on glutamate-induced biophotonic activity in mouse coronal brain slices. A–E Arrows indicate the time points for application of ACh, DA, NE, 5-HT, and GABA during the maintenance period of the action of 50 mmol/L glutamate (150 min). Representative dynamic changes in the biophotonic activity demonstrated by relative gray values (RGVs) in a slice are shown in the left panels in A, B, C, and E and in the upper panel in D. The sum of the time course of the average change of RGVs from 15 continuously-processed original gray images is shown in the right panels in A and B, the middle panels in C and E, and the lower panel in D. Application of 75 mmol/L ACh, 10 mmol/L DA, or 500 mmol/L GABA resulted in significant enhancement of biophotonic activity (A, B, D, n = 6 for ACh and DA; n=5 for GABA). Two different effects were found after the application of 20 mmol/L NE (C). A sustained enhancement occurred after a brief inhibitory effect for~3 min if the action of glutamate was greater (type I, blue line, middle and right panels in C, n = 13); a slight sustained inhibitory effect occurred if the action of glutamate was weaker, and a recovery was observed after long-lasting application (type II, green line, middle and right panels in C, n = 17). 5-HT (20, 100, and 500 μmol/L, n = 6) significantly decreased biophotonic activity in a dose-dependent manner (E, right panel). F–K Representative dynamic changes in biophotonic activity measured as RGVs in a slice are shown in each colored line in the left panels. The right panels show the sum of the time course of the average change of RGVs from 15 continuously-processed original gray images. The left arrow indicates the time point for application of glutamate (0 min), ACh, DA, or NE (150 min) (middle), and propofol, 5-HT, or GABA (270 min) (right) in each panel. F Glutamate-induced biophotonic activity was slightly influenced by propofol at 10 μmol/L (n = 6) but significantly by 20 μmol/L (n = 10) and 80 μmol/L (n = 6), and recovery occurred after long-lasting application. G Sustained enhancement effect of 75 mmol/L ACh on the action of glutamate was not influenced by propofol at 10 μmol/L (n = 4) but significantly by 20 μmol/L (n = 6) and 80 μmol/L (n = 10), and recovery occurred after long-lasting application. H The “bell shaped” effect of 10 mmol/L DA on the action of glutamate was not influenced by propofol at 10 μmol/L (n = 6) but significantly by 20 μmol/L (n = 6) and 80 μmol/L (n = 8). I The “type II” effect of 20 mmol/L NE on the