Applications of laser-induced fluorescence spectroscopy for the determination of NADH in experimental neuroscience

Abstract

There is an increasing need for continuously monitoring changes in brain metabolism and neuronal activity, respectively. The aim is to improve our understanding of mechanisms involved in physiological as well as pathophysiological and behavioural responses and to characterise drug actions. Changes of NADH concentration in the brain can be regarded as an index of changes in mitochondrial activity, which is closely related to neuronal activity. During the last decade the determination of NADH fluorescence by laser-induced fluorescence spectroscopy has become a method of choice in the study of mitochondrial metabolism in neuroscience. By now, small optical probes, providing excellent temporal and spatial resolution and the development of reliable and robust laser-based fluorescence detectors allow a widespread use in preclinical research. Besides in vitro studies, especially the assessment of changes in the NADH fluorescence in vivo has been shown to provide valuable information on brain function. Several applications are given, ranging from studying drug action or the extent of brain lesion to the measurement the time course of NADH concentration in a brain region of an awake and behaving laboratory rat. Theoretical aspects, opportunities, and limitations that have to be considered during the implementation of fluorescence spectroscopy are described. It is concluded, that measurement of NADH fluorescence by laserinduced fluorescence spectroscopy is a suitable tool for investigation of functional processes in the brain. Distribution and intensity of the NADH fluorescence in coronal rat brain slices containing the hippocampus. The data represent the intensity of the NADH fluorescence in arbitrary units and are shown as averaged data (n=5) from each measuring point, respectively

Altered nicotinamide adenine dinucleotide (NADH) fluorescence in dtsz mutant hamsters reflects differences in striatal metabolism between severe and mild dystonia

“…Concentrations of nicotinamide adenine dinucleotide (NADH), a cosubstrate for energy transfer in the respiratory chain, mirror mitochondrial oxidative metabolism in vitro (Shuttleworth et al, 2003) as well as in vivo (Ince et al, 1992; Rex et al, 1999). Determination of changes in NADH fluorescence, reflecting changes in CNS metabolism with high spatial and time resolution using laser‐induced fluorescence spectroscopy in vivo, is an established method (Mottin et al, 2003; Rex and Fink, 2006a, b). Therefore, this technique was used to measure metabolic activity, indicating changes in neuronal activity.…”

Pharmacokinetic aspects of reduced nicotinamide adenin dinucleotide (NADH) in rats

“…The time course of the NADH absorption in vitro was determined by the NADH fluorescence measurement continuously using the laser-induced fluorescence spectroscopy (4,35). In the preceding experiment we could show that the fluorescence intensity and the concentration of NADH in an aqueous solution are closely and directly proportional and therefore even quantification of the NADH absorbed was possible.…”

“…Mitochondrial dysfunction may cause or is involved in many pathological states like common neurodegenerative diseases (1,2). Consequently, in vitro and in vivo measurement of NADH fluorescence is a well established method to evaluate mitochondrial function in the brain (for review see (3,4).…”

Calculations regarding cell metabolism stimulation using photons in the visible wavelength range

“…Their cellular concentration can be measured by laser-induced fluorescence techniques. Rex et al [9] showed that these compounds are ideal indicators to assess the mitochondrial metabolism activity and that changes in the concentrations reflect an index of mitochondrial activity. However the release of the produced energy is coupled to the translocalisation of protons from the sub-cellular matrix to the outer side of the mitochondrial membrane.…”