1. Voltage-Sensitive Fluorescence of Indocyanine Green in the Heart
Irma Martišienė, Regina Mačianskienė, Rimantas Treinys, Antanas Navalinskas, Mantė Almanaitytė, Dainius Karčiauskas, Audrius Kučinskas, Ramunė Grigalevičiūtė, Vilma Zigmantaitė, Rimantas Benetis, Jonas Jurevičius 
Biophysical Journal 
Volume 110, Issue 3, Pages (February 2016)
DOI: /j.bpj
Copyright © 2016 Biophysical Society Terms and Conditions

2. Figure 1
ICG OS (excitation at 780 nm, emission at 800 nm) in Langendorff-perfused rabbit heart. (A) Simultaneously recorded OS (in auxiliary units, solid lines) and contractions (in milligrams, dots) in the presence of 20 μmol/L blebbistatin alone (gray) and combined with 5 mmol/L BDM (red) in the perfusion solution. (B) Amplitude map of the OS recorded in the presence of both blebbistatin and BDM (the scale bar is in %, below). Numbers near isolines show the amplitude of the fractional fluorescence (ΔF/F) in %. The interval between isolines is 0.1%. The solid horizontal line represents the spatial scale of the map (in millimeters). (C) Overlapped original recordings of OSs obtained at five different places with areas of 5 × 5 pixels on the amplitude map (from the squares labeled by letters in B). Note that in different parts of the field of view, the obtained OSs have similar shapes, but the activation times are different. The OS is presented in reversed-polarity mode.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2016 Biophysical Society Terms and Conditions

3. Figure 2
ICG OS recordings at various excitation and emission wavelengths. (A–C) OSs obtained with green (λex = 530 nm; OS530/720), yellow (λex = 590 nm; OS590/720), and red (λex = 660 nm; OS660/720) excitation, respectively, and λem > 720 nm. (E–H) OSs obtained with yellow (λex = 590 nm; OS590/800), red (λex = 660 nm; OS660/800), cherry (λex = 735 nm; OS735/800), and brown (λex = 780 nm; OS780/800) excitation, respectively, and λem > 800 nm. The fluorescence emission was collected using long-pass filters. (D) The OSs obtained at 590/720 nm and 660/720 nm were used to calculate the OS590/720/OS780/800 (yellow) and OS660/720/OS780/800 (red) ratios, respectively, relative to the OS at 780/800 nm.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2016 Biophysical Society Terms and Conditions

4. Figure 3
OSs obtained using ICG. (A) OS780/800 (red), OS fast component (OSf, magenta), and electrical AP simultaneously recorded using a glass microelectrode (black). Please note that the AP and the presented OSs were recorded at the same cardiac tissue location. (B) OS780/800 (red) and its fast and slow components (magenta and gray, respectively). (C) OSf (magenta) and OSs (gray) components together with the derivative signal, which was obtained by exponential smoothing of OSf to OSs (OSs(smoothed), dashed).
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2016 Biophysical Society Terms and Conditions

5. Figure 4
Change in ICG OS at various excitation and emission wavelengths. (A–D) OS resulting from excitation at 590 nm (yellow), 660 nm (red), 735 nm (cherry), and 780 nm (brown). The fluorescence emission was collected using band-pass filters (see Materials and Methods). The calculated (black) OSs are superimposed on the experimental signals (yellow, red, cherry, and brown), which are given as ΔF/F in %. The calculated values for the fast (OSf, magenta) versus slow (OSs, gray) OS components at various λex and λem wavelengths are given in insets. Importantly, to obtain less noisy signals, the data presented here were taken from a 20 × 20 pixel area during atrial pacing, when there is almost no lateral propagation of the electrical signal.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2016 Biophysical Society Terms and Conditions

6. Figure 5
Effects of the ICG fluorescent dye on OAP parameters. Activation-time (top) and duration (bottom) maps of OS780/800 (left) and its fast (middle) and slow (right) components. The numbers near the isolines and scale bars show the activation time and duration in milliseconds. The interval between isolines on the activation-time maps is 5 ms, and that on the duration maps is 10 ms. Please note that the activation wave moves in the direction from blue-green traces to red ones. The solid horizontal line provides the spatial scale of the maps (in millimeters).
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2016 Biophysical Society Terms and Conditions

7. Figure 6
The ICG OS correlates with the electrical AP in the presence and absence of pinacidil. (A) Superimposition of the OSf (magenta) and OSs (gray) components for comparison with the electrical AP that was simultaneously recorded using a glass microelectrode (black). Please note that the AP and the presented OSs were recorded at the same cardiac tissue location. (B) Changes in OSf (magenta) and the electrical AP (black) after the application of 50 μM pinacidil (blue and dashed, respectively). (C) Superimposition of OSf, OSs, and the AP after the application of pinacidil. The dashed horizontal line provides the zero value (mV).
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2016 Biophysical Society Terms and Conditions