GEVIBench › All sensors › ASAP7y
ASAP7y
Red-shifted ASAP5 variant optimized for ultrasensitive subthreshold voltage imaging, with a steep response near resting potential and excitation compatibility extending to high-power 1030-nm fiber lasers.
- Category: VSD-cpGFP GEVI
- Published: 2026-05-31 — bioRxiv 2026
- Derived from: ASAP5
- Response polarity: negative-going (fluorescence decreases on depolarization)
- Spectrum: excitation peak 510 nm, emission peak 525 nm (ASAP7y)
- Two-photon compatible: yes
- Tags: cpGFP, Green, Two-photon, Subthreshold
Headline values (as shown in the GEVIBench table)
| Metric | Value | Definition |
|---|---|---|
| Brightness (B/B_EGFP) | 0.34× EGFP | Molecular brightness relative to EGFP (extinction coefficient × quantum yield, or a measured ratio). Sensors not measured against EGFP directly are placed through a chain of pairwise brightness comparisons, combined by geometric mean. |
| Kinetics τ_on / τ_off (ms) | 0.90 / 2.7 ms | Activation / decay time constants in ms (amplitude-weighted mean τ for multi-exponential fits). The value shown averages the measurements made at physiological temperature (≥33 °C); if there are none, it is the measurement closest to 33 °C. |
| ΔF/F per 100 mV | -80% | Steady-state fluorescence change for a 100 mV depolarization step (−70 → +30 mV); the sign gives the polarity. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. |
| ΔF/F per mV | 2% | Subthreshold sensitivity: fluorescence change per mV near rest (−90 to −50 mV). Where no value is reported directly, it is estimated from the F–V curve. |
| ΔF/F per AP | 62% (median of 3 measurements: 62%) | Fluorescence change per single action potential in neurons. The table shows the first listed measurement; the median across measurements (one-photon preferred) is used for sorting. |
| AP width (FWHM, ms) | 10 ms | Full width at half maximum of the optical spike waveform. |
| Photostability t75% @ 100 mW/mm² | 1.3 s | Time for fluorescence to fall to 75% of its initial value under one-photon illumination, linearly dose-scaled to 100 mW/mm² (t50% is used where the 75% crossing falls inside a fast initial transient). Two-photon curves are not dose-scaled and are excluded. |
| Papers using it (N_used) | 3 | Number of published research papers, tracked by GEVIBench, that used the sensor for an experiment (a popularity / track-record measure). |
Measurements and sources
Kinetics
- τ_on 0.9 ms, τ_off 2.7 ms at 37°C — Hao 2026, Ext. Fig. 1b
- τ_on 3 ms, τ_off 10.7 ms at 25°C — Hao 2026, Ext. Fig. 1b
ΔF/F per 100 mV
- -80%, 1P — Hao 2026, Fig. 1b
ΔF/F per mV (subthreshold)
- 2.7%/mV (Voltage-fluorescence conversion ratio around resting membrane potential in HEK293 cells (2-fold higher than ASAP5 at 1.3%/mV)) — Hao 2026, Fig. 1b
- 1.9%/mV (In vivo whole-cell patch-clamp near resting membrane voltage in mouse visual cortex) — Hao 2026, Fig. 1f
- 2%/mV (Subthreshold -ΔF/F₋₇₀ per mV measured in cultured rat cortical neurons during current-injection-evoked plateau potentials (n = 7 cells; P < 0.0001 vs ASAP5). Read off the Fig. 1d bar chart, whose y-axis is literally 'Subthreshold -ΔF/F₋₇₀ per mV (%)': ASAP7y bar ≈ 2.0%/mV vs ASAP5 ≈ 0.78%/mV, consistent with the main text's 'responses to subthreshold activities were 140% larger'. This is the neuronal counterpart of the 2.7%/mV HEK293 F-V slope (Fig. 1b) and the 1.9%/mV in-vivo value (Fig. 1f). (The Ext. Fig. 1c commanded 3-mV EPSP gives the same figure independently: -6% ΔF/F0 ÷ 3 mV = 2.0%/mV in HEK293 at 37°C.)) — Hao 2026, Fig. 1d
ΔF/F per action potential
- 62%, 1P — Hao 2026, Ext. Fig. 1c
- 24%, 2P — Hao 2026, Fig. 2k
- 46% — Hao 2026, Fig. 1c
AP width (FWHM)
- 10.3 ms at undefined Hz sampling, Rat, cultured cortical neurons, current-evoked APs, in vitro — Hao 2026, Fig. 1c
Brightness comparisons
- 1.28× the brightness of ASAP5 — Hao 2026, Fig. 2l
Photobleaching
- t75% = 12600 s (extrapolated) at ~10 µW/mm² (445 nm, in vivo), 1P — Hao 2026, Ext. Fig. 3a
- curve only (did not reach 75% within the measured window) at 16 mW at 940 nm (2P power-only), 2P — Hao 2026, Fig. 2g
Fluorescence–voltage (F–V) curve
ΔF/F (%) at each membrane potential, normalized to 0 at −70 mV: -120 mV: 100%; -100 mV: 78%; -80 mV: 25%; -70 mV: 0%; -60 mV: -30%; -40 mV: -60%; -20 mV: -75%; 0 mV: -80%; 30 mV: -85%; 80 mV: -90% — Hao 2026, Fig. 1b
Research papers using ASAP7y (3)
- Ultrasensitive voltage imaging reveals distinct electrical microdomains in neurons — Hao YA, Jayne LL, Lee S, Dittrich MN, Zhang M, Haziza S, Bendifallah I, Sims RR, Bouazza-Arostegui B, White AD, Kochalka J, Wang Y, Seyedmohadesin M, Negrean A, Li Z, Chiu C, Podgorski K, Ding JB, Deisseroth K, Yuste R, Emiliani V, Schnitzer MJ, Lin MZ, Clandinin TR, bioRxiv 2026 (HEK293 cells, in vitro; rat cortical neurons, in vitro; mouse organotypic hippocampal slices; mouse visual cortex, in vivo; Drosophila visual system, in vivo)
- Intrinsic space-time couplings governing multi-scale cortical dynamics — White AD, Wang Y, Kochalka J, Hao YA, Li C, Hernandez M, Andini N, Pyo KE, Wenderski W, Mitra A, Eshaghi Gharagoz B, Kadur C, Ganguli S, Clandinin TR, Lin MZ, Deisseroth K, bioRxiv 2026 (Mouse, dorsal cortex (cortex-wide voltage imaging), in vivo)
- Causal and directional elements of global brain dynamics — Kochalka J, Mitra A, White AD, Wang Y, Sheng K, Hao YA, Kadur C, Ramakrishnan C, Hernandez M, Wenderski W, Po KE, Andini N, Clandinin TR, Lin MZ, Druckmann S, Deisseroth K, bioRxiv 2026 (Mouse, cortex-wide (excitatory and inhibitory neurons), in vivo)
Data and citation
- llms.txt — summary for language models
- llms-full.txt — every sensor in full (Markdown)
- gevis.json — all values and measurements with sources (JSON)
- gevis.csv — one row per sensor (CSV)
Cite GEVIBench as: Adam E. Cohen and Daozheng Gong (2026). Voltage imaging: A practical guide. Neuron. https://doi.org/10.1016/j.neuron.2026.08.002
Generated from the GEVIBench database on 2026-10-12.