Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2015 Jul 22;593(Pt 17):3865–3884. doi: 10.1113/JP270510

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society

PMC Copyright notice

DuoCaN activation in response to field stimulation in aGPVMs

A–D, indo-1 and DuoCaN sensor signals from an exemplar cell are shown. A, a single pulse elicits a calcium transient (A₁, black). The sensor is not activated and _sensor remains at the baseline (A₂, red). Scale bar indicates normalized change of the signal throughout. Normalized CFP (A₂) and FRET (A₃) channels are silent. B, stimulation at 0.2 Hz results in calcium transients in the cell (B₁). The corresponding sensor response is shown (B₂) illustrating a small decrease (∼0.005); the fit to activation (solid black) and inactivation (solid grey) is indicated. Individual FRET (B₃) and CFP (B₄) channel signals are shown with the change largely masked by motion artifacts. C, a 0.5 Hz stimulation train elicits calcium transients gradually increasing in amplitude, with upward shifting baseline indicating calcium summation (C₁). This in turn activates the sensor as is apparent from the change in FR (C₂). Corresponding FRET (C₃) and CFP (C₄) channels are also shown. D, pacing at 1 Hz for 30 s leads to a robust increase in sensor activation (D₂) with subsequent decline to the basal level after the pacing was turned off. Individual FRET (D₃) and CFP (D₄) channels are shown. Strong motion artifacts are present in each individual signal and disappear in _sensor (D₂). E, DuoCaN sensor expression and distribution in aGPVMs evaluated by imaging through CFP channel (green) and di-4-ANEPPS (red). The sensor is located in the vicinity of T-tubules, as demonstrated by the overlay of the two channels (bottom). F, population data of sensor activation versus stimulation frequencies are plotted (grey filled circles and solid black line for the trend-line, average of n = 4–10 cells for each point). The sensor activation shows a gradual rise in amplitude as the pacing rate is increased. The aGPVMs are contrasted with the corresponding nearly flat NRVM trend-line (dashed-grey). G, the half-time to activation from quiescent state in aGPVMs is around 5 s at 0.5 Hz and 10 s at 1 Hz (black filled circles and black line), which is about 5 times slower than that of NRVMs (dashed grey line).

Inline graphic — DuoCaN activation in response to field stimulation in aGPVMs

A–D, indo-1 and DuoCaN sensor signals from an exemplar cell are shown. A, a single pulse elicits a calcium transient (A₁, black). The sensor is not activated and _sensor remains at the baseline (A₂, red). Scale bar indicates normalized change of the signal throughout. Normalized CFP (A₂) and FRET (A₃) channels are silent. B, stimulation at 0.2 Hz results in calcium transients in the cell (B₁). The corresponding sensor response is shown (B₂) illustrating a small decrease (∼0.005); the fit to activation (solid black) and inactivation (solid grey) is indicated. Individual FRET (B₃) and CFP (B₄) channel signals are shown with the change largely masked by motion artifacts. C, a 0.5 Hz stimulation train elicits calcium transients gradually increasing in amplitude, with upward shifting baseline indicating calcium summation (C₁). This in turn activates the sensor as is apparent from the change in FR (C₂). Corresponding FRET (C₃) and CFP (C₄) channels are also shown. D, pacing at 1 Hz for 30 s leads to a robust increase in sensor activation (D₂) with subsequent decline to the basal level after the pacing was turned off. Individual FRET (D₃) and CFP (D₄) channels are shown. Strong motion artifacts are present in each individual signal and disappear in _sensor (D₂). E, DuoCaN sensor expression and distribution in aGPVMs evaluated by imaging through CFP channel (green) and di-4-ANEPPS (red). The sensor is located in the vicinity of T-tubules, as demonstrated by the overlay of the two channels (bottom). F, population data of sensor activation versus stimulation frequencies are plotted (grey filled circles and solid black line for the trend-line, average of n = 4–10 cells for each point). The sensor activation shows a gradual rise in amplitude as the pacing rate is increased. The aGPVMs are contrasted with the corresponding nearly flat NRVM trend-line (dashed-grey). G, the half-time to activation from quiescent state in aGPVMs is around 5 s at 0.5 Hz and 10 s at 1 Hz (black filled circles and black line), which is about 5 times slower than that of NRVMs (dashed grey line).