Journal: Journal of Biomedical Optics

Article Title: Two-photon microscopy of cortical NADH fluorescence intensity changes: correcting contamination from the hemodynamic response

doi: 10.1117/1.3633339

Figure Lengend Snippet: (a) Schematic of the cortical surface. Excitation and detection cones are defined by objective NA. (b) Normalized emission spectra of NADH and SR101 (thick solid lines), transmission of emission filters in NADH and SR101 detection channels (dashed lines), and HbO and HbR molar extinction coefficients (thin solid lines).

Article Snippet: 2 , 3 In addition to linear excitation of NADH fluorescence, a relatively small but sufficient two-photon absorption cross section exists in the near-infrared spectrum from 700 to 750 nm, 4 which allows two-photon laser scanning microscopy (TPLSM) imaging of NADH fluorescence.

Techniques: Transmission Assay

Journal: Journal of Biomedical Optics

Article Title: Two-photon microscopy of cortical NADH fluorescence intensity changes: correcting contamination from the hemodynamic response

doi: 10.1117/1.3633339

Figure Lengend Snippet: Comparison of the ray-tracing algorithm with the experimental data. (a) Maximum intensity projection (MIP) of a 400-μm-thick microvascular stack labeled with FITC in rat primary somatosensory cortex. (b) MIP of the 110-μm-thick reconstructed microvasculature obtained from (a) using microvascular graphing. Vessel diameters were presented with different shades of gray. (c, e) TPLSM images of NADH and SR101 fluorescence intensities at a depth of 110 μm. Scale bars are 100 μm. (d, f) Fluorescence intensity profiles (black dots) along the white dotted lines from (c) and (e), respectively. Solid lines represent the results of the full ray-tracing algorithms (fluorescence excitation and emission detection), while dashed lines represent ray-tracing results based on blood absorption of emission detection only.

Article Snippet: 2 , 3 In addition to linear excitation of NADH fluorescence, a relatively small but sufficient two-photon absorption cross section exists in the near-infrared spectrum from 700 to 750 nm, 4 which allows two-photon laser scanning microscopy (TPLSM) imaging of NADH fluorescence.

Techniques: Comparison, Labeling, Fluorescence

Journal: Journal of Biomedical Optics

Article Title: Two-photon microscopy of cortical NADH fluorescence intensity changes: correcting contamination from the hemodynamic response

doi: 10.1117/1.3633339

Figure Lengend Snippet: Dependence of detected relative NADH fluorescence intensity on microvascular structure and imaging parameters. (a–c) Relative NADH fluorescence intensity dependence on vessel diameter (5–80 μm) and lateral distance at imaging depths of 20, 50, and 100 μm, respectively. (d, e) summarize the information presented in (a–c). Contour lines represent 50 and 90% intensity levels. (f) Influence of objective NA on detected relative NADH signal in the presence of the pial vessel with 50-μm diameter at three imaging depths (20, 50, and 100 μm).

Article Snippet: 2 , 3 In addition to linear excitation of NADH fluorescence, a relatively small but sufficient two-photon absorption cross section exists in the near-infrared spectrum from 700 to 750 nm, 4 which allows two-photon laser scanning microscopy (TPLSM) imaging of NADH fluorescence.

Techniques: Fluorescence, Imaging

Journal: Journal of Biomedical Optics

Article Title: Two-photon microscopy of cortical NADH fluorescence intensity changes: correcting contamination from the hemodynamic response

doi: 10.1117/1.3633339

Figure Lengend Snippet: Influence of blood volume and hemoglobin oxygen saturation changes on the detected NADH fluorescence intensity given no changes in NADH concentration. (a–c) Influence of ±20% changes in HbT on the NADH signal. (d–f) Influence of SO2 changes on the NADH signal. The relative changes in the NADH signal in (d–f) were calculated with respect to SO2 = 75%. Contour lines represent ±0.1, ±1, and ±10% changes in detected NADH fluorescence intensity as a function of lateral distance, relative HbT (rHbT), SO2, pial vessel diameter (10, 20, and 50 μm) and imaging depth (20, 50, and 100 μm).

Article Snippet: 2 , 3 In addition to linear excitation of NADH fluorescence, a relatively small but sufficient two-photon absorption cross section exists in the near-infrared spectrum from 700 to 750 nm, 4 which allows two-photon laser scanning microscopy (TPLSM) imaging of NADH fluorescence.

Techniques: Fluorescence, Concentration Assay, Imaging

Journal: Journal of Biomedical Optics

Article Title: Two-photon microscopy of cortical NADH fluorescence intensity changes: correcting contamination from the hemodynamic response

doi: 10.1117/1.3633339

Figure Lengend Snippet: Influence of blood volume changes on the detected NADH fluorescence intensity assuming a true +2% change in NADH fluorescence. (a–i) show the relative error of the detected change in NADH fluorescence intensity (ΔNADH/NADH0) given a ±20% range of change in HbT, different vessel diameters (10, 20, and 50 μm), and imaging depths (20, 50, and 100 μm) as a function of lateral distance. Contours show the relative NADH error of ±1, ±10, and ±100%. Shaded regions signify the importance of a ⩽−100% detection error, where measurements affected by the HbT changes show the opposite sign from the true NADH fluorescence changes.

Article Snippet: 2 , 3 In addition to linear excitation of NADH fluorescence, a relatively small but sufficient two-photon absorption cross section exists in the near-infrared spectrum from 700 to 750 nm, 4 which allows two-photon laser scanning microscopy (TPLSM) imaging of NADH fluorescence.

Techniques: Fluorescence, Imaging

Journal: Journal of Biomedical Optics

Article Title: Two-photon microscopy of cortical NADH fluorescence intensity changes: correcting contamination from the hemodynamic response

doi: 10.1117/1.3633339

Figure Lengend Snippet: Correction procedure applied to the detected NADH fluorescence intensity changes during mild hypoxia and hyperoxia. (a–c) Mild hypoxia with FiO2 = 16.8%. (a, b) NADH and SR101 fluorescence intensities, respectively, 55 μm below cortical surface. (c) Temporal profiles of relative noncorrected NADH and SR101 fluorescence intensity changes from the ROIs outlined by white lines in (a) and the corresponding corrected NADH signal obtained by using simple correction procedure with K = 1.15. An initial ∼3 min. of normoxia (FiO2 = 21%) was followed by 7 min. of mild hypoxia (FiO2 = 16.8%). The hypoxic period is marked by the black bar in (c). (d–f) Mild hypoxia with FiO2 = 14.7%, 50 μm below cortical surface. (g–i) Hyperoxia with FiO2 = 100%, 70 μm below cortical surface. Scale bar: 100 μm.

Article Snippet: 2 , 3 In addition to linear excitation of NADH fluorescence, a relatively small but sufficient two-photon absorption cross section exists in the near-infrared spectrum from 700 to 750 nm, 4 which allows two-photon laser scanning microscopy (TPLSM) imaging of NADH fluorescence.

Techniques: Fluorescence

Journal: Journal of Biomedical Optics

Article Title: Two-photon microscopy of cortical NADH fluorescence intensity changes: correcting contamination from the hemodynamic response

doi: 10.1117/1.3633339

Figure Lengend Snippet: Influence of blood volume changes on the detected NADH fluorescence intensity using our correction procedure given a +2% true change in NADH fluorescence. (a–i) show the relative error of the corrected change in NADH fluorescence intensity (ΔNADH/NADH0) given a ±20% range of change in HbT, different vessel diameters (10, 20, and 50 μm) and imaging depths (20, 50, and 100 μm) as a function of lateral distance. Contours show the relative NADH error of ±1, ±10, and ±100%. Shaded regions signify the importance of a ⩽−100% detection error, where measurements affected by the HbT changes show the opposite sign from the true NADH fluorescence changes. The value of the correction factor was 1.15.

Article Snippet: 2 , 3 In addition to linear excitation of NADH fluorescence, a relatively small but sufficient two-photon absorption cross section exists in the near-infrared spectrum from 700 to 750 nm, 4 which allows two-photon laser scanning microscopy (TPLSM) imaging of NADH fluorescence.

Techniques: Fluorescence, Imaging

Journal: Journal of Biomedical Optics

Article Title: Two-photon microscopy of cortical NADH fluorescence intensity changes: correcting contamination from the hemodynamic response

doi: 10.1117/1.3633339

Figure Lengend Snippet: NADH fluorescence emission intensity change during respiratory arrest. (a) Maximum intensity projection of a 200-μm-thick microvascular stack labeled with FITC in rat SI cortex. (b) NADH fluorescence intensity map 100 μm below cortical surface. Scale bar: 100 μm. (c) Temporal profile of relative NADH fluorescence intensity changes from the ROI outlined by black line in (b). An initial 95 s of normal breathing (FiO2 = 21%) was followed by 70 s of respiratory arrest and subsequent return to normal breathing. The respiratory arrest period is marked by the black bar in (c).

Article Snippet: 2 , 3 In addition to linear excitation of NADH fluorescence, a relatively small but sufficient two-photon absorption cross section exists in the near-infrared spectrum from 700 to 750 nm, 4 which allows two-photon laser scanning microscopy (TPLSM) imaging of NADH fluorescence.

Techniques: Fluorescence, Labeling