The role of mitochondrial complex I in ultraweak photon-induced delayed photon emission [delayed luminescence (DL)] of human leukemia Jurkat T cells was probed by using complex I targeting agents like rotenone, menadione, and quercetin. Rotenone, a complex I-specific inhibitor, dose-dependently increased the mitochondrial level of reduced nicotinamide adenine dinucleotide (NADH), decreased clonogenic survival, and induced apoptosis. A strong correlation was found between the mitochondrial levels of NADH and oxidized flavin mononucleotide (FMNox) in rotenone-, menadione- and quercetin-treated cells. Rotenone enhanced DL dose-dependently, whereas quercetin and menadione inhibited DL as well as NADH or FMNox. Collectively, the data suggest that DL of Jurkat cells originates mainly from mitochondrial complex I, which functions predominantly as a dimer and less frequently as a tetramer. In individual monomers, both pairs of pyridine nucleotide (NADH/reduced nicotinamide adenine dinucleotide phosphate) sites and flavin (FMN-a/FMN-b) sites appear to bind cooperatively their specific ligands. Enhancement of delayed red-light emission by rotenone suggests that the mean time for one-electron reduction of ubiquinone or FMN-a by the terminal Fe/S center (N2) is 20 or 284 μs, respectively. All these findings suggest that DL spectroscopy could be used as a reliable, sensitive, and robust technique to probe electron flow within complex I in situ.

These results suggest that a history of strabismus and a deep amblyopia are more likely to be associated with temporal misperceptions than a refractive etiology and a mild acuity loss. A temporally unstable perception may be related to a more profound disorganization of the central neural pathways connected to the amblyopic eye.

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The aim of this study was to investigate the spatial and temporal distortions that occur in strabismic and anisometropic amblyopic vision. Twelve subjects with strabismic (n = 4), anisometropic (n = 4), mixed amblyopia (n = 3) and bilateral refractive amblyopia (n = 1) were asked to describe and sketch their subjective percept of different geometrical patterns, as seen with their amblyopic eye. Based on their descriptions, computer-animated patterns were generated, which were then validated by the subjects. Both spatial distortions and temporal instability were perceived mainly by strabismic and strabismic-anisometropic amblyopes. Temporal instability occurred mainly at high spatial frequencies. Our data suggest that strabismus, in addition to amblyopia, is needed to elicit significant spatial and temporal distortions. The occurrence of these distortions may be related to the early history of each subject.

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The purpose of this study is to quantify the temporal characteristics of spatial misperceptions in human amblyopia. Twenty-two adult participants with strabismus, strabismic, anisometropic, or mixed amblyopia were asked to describe their subjective percept of static geometrical patterns with different spatial frequencies and shapes, as seen with their non-dominant eye. We generated digital reconstructions of their perception (static images or movies) that were subsequently validated by the subjects using consecutive matching sessions. We calculated the Shannon entropy variation in time for each recorded movie, as a measure of temporal instability. Nineteen of the 22 subjects perceived temporal instabilities that can be broadly classified in two categories. We found that the average frequency of the perceived temporal instabilities is ∼1 Hz. The stimuli with higher spatial frequencies yielded more often temporally unstable perceptions with higher frequencies. We suggest that type and amount of temporal instabilities in amblyopic vision are correlated with the etiology and spatial frequency of the stimulus.