Journal: bioRxiv

Article Title: Chronic alteration of Ca 2+ and hemodynamic signals induced by intracortical microstimulation in the visual cortex of awake mice

doi: 10.1101/2025.10.23.679242

Figure Lengend Snippet: ( A ) Timeline of chronic recordings. ( B ) Imaging and stimulation setups. Widefield and two-photon imaging was performed on the implanted hemisphere, and visual stimulation was applied to the contralateral eye. ( C ) Example widefield images of neural (Ca 2+ dF/F 0 ) and OEF hemodynamic responses induced by 25-Hz ICMS. Scale bar = 500 µm. ( D and E ) Time course (left) and distance profile (right; measured at 5 [red] and 20 [blue] seconds after stimulation onset) of induced neural (D) and hemodynamic (E) responses. Mean ± SD across four trials. Shaded bar indicates stimulation period (0-10 s); vertical dashed lines mark the time points of distance profiles.

Article Snippet: Custom stimulation microelectrodes (Q1×4-3mm-50-703-CM16LP, NeuroNexus Technologies, single 3-mm-long shank, 30-μm-diameter four channels, 50-μm site spacing, electrochemically activated iridium/iridium oxide sites ) were implanted at an angle of 20-30 degrees slanted towards the posterior region.

Techniques: Imaging

Journal: bioRxiv

Article Title: Chronic alteration of Ca 2+ and hemodynamic signals induced by intracortical microstimulation in the visual cortex of awake mice

doi: 10.1101/2025.10.23.679242

Figure Lengend Snippet: ( A ) Coefficient of variation (CV, pixel-wise standard deviation normalized by mean over time) of widefield Ca 2+ (i) and hemodynamics (ii) during pre-stimulation periods at day 0 (top) and day 14 (bottom). ( B ) CV (top) and silencing index relative to 350 µm (SI 350 = [CV d -CV 350 ]/CV 350 , where d = 50, 150, 250, 350, or 450 μm) during pre-stimulation periods (bottom) across distances and imaging days. ( C ) CV map during visual stimulation. ( D ) CV and SI 350 during visual stimulation. * in SI 350 plots indicate significant differences from 0 (one-sample t-test with Bonferroni correction, p < 0.05; colors correspond to days after implantation).

Article Snippet: Custom stimulation microelectrodes (Q1×4-3mm-50-703-CM16LP, NeuroNexus Technologies, single 3-mm-long shank, 30-μm-diameter four channels, 50-μm site spacing, electrochemically activated iridium/iridium oxide sites ) were implanted at an angle of 20-30 degrees slanted towards the posterior region.

Techniques: Standard Deviation, Imaging

Journal: bioRxiv

Article Title: Chronic alteration of Ca 2+ and hemodynamic signals induced by intracortical microstimulation in the visual cortex of awake mice

doi: 10.1101/2025.10.23.679242

Figure Lengend Snippet: ( A-C ) Example colormaps from a single mouse showing Ca 2+ responses during ( A ) 25-Hz ICMS, ( B ) 250-Hz ICMS, and ( C ) visual stimulation at (i and ii) day 0 and (iii and iv) day 21. Only increases from pre-stimulation baseline are shown in red. Corresponding time courses within 500 µm from the stimulation site are shown in (v) (mean ± SD across 4 trials). ( D-F ) Chronic comparisons of Ca 2+ activation magnitude (D), spatial spread (E), and duration (F) across days post-insertion. Mean ± SEM across mice. * next to line plot indicates a significant effect of day (LME model).

Article Snippet: Custom stimulation microelectrodes (Q1×4-3mm-50-703-CM16LP, NeuroNexus Technologies, single 3-mm-long shank, 30-μm-diameter four channels, 50-μm site spacing, electrochemically activated iridium/iridium oxide sites ) were implanted at an angle of 20-30 degrees slanted towards the posterior region.

Techniques: Activation Assay

Journal: bioRxiv

Article Title: Chronic alteration of Ca 2+ and hemodynamic signals induced by intracortical microstimulation in the visual cortex of awake mice

doi: 10.1101/2025.10.23.679242

Figure Lengend Snippet: ( A ) Example Ca 2+ response images at days 0 and 7 under (i) 25-Hz ICMS, (ii) 250-Hz ICMS, and (iii) visual stimulation. Corresponding time courses are shown in (iv; mean ± SEM across cells for soma, mean ± SEM across repeats for neuropil; scale bars = 5 s and 5%). ( B and C ) Chronic comparisons of somatic activation magnitudes (B) and durations (C). ( D and E ) Somatic depression magnitude (D) and duration (E) across days. ( F and G ) Neuropil activation magnitude (F) and duration (G) across days. ( H and I ) Neuropil depression magnitude (H) and duration (I) across days. Mean ± SEM across cells (B-E) or mice (F-I); “<“ and “>“ indicate significant differences compared with days 0 and 84, respectively (LME model followed by Welch’s t-test with Holm-Bonferroni correction).

Article Snippet: Custom stimulation microelectrodes (Q1×4-3mm-50-703-CM16LP, NeuroNexus Technologies, single 3-mm-long shank, 30-μm-diameter four channels, 50-μm site spacing, electrochemically activated iridium/iridium oxide sites ) were implanted at an angle of 20-30 degrees slanted towards the posterior region.

Techniques: Activation Assay

Journal: bioRxiv

Article Title: Chronic alteration of Ca 2+ and hemodynamic signals induced by intracortical microstimulation in the visual cortex of awake mice

doi: 10.1101/2025.10.23.679242

Figure Lengend Snippet: ( A-C ) Example colormaps of a single mouse showing Ca 2+ responses after ( A ) 25-Hz ICMS, ( B ) 250-Hz ICMS, and ( C ) visual stimulation at (i and ii) day 0 and (iii and iv) day 21. Only decreases from pre-stimulation baseline are shown in blue; darker blue indicates stronger depression. Corresponding time courses within 500 µm from the stimulation site are shown in (v) (mean ± SD across 4 trials). Traces during the stimulation period (0-10 s) are omitted for clarity. ( D-F ) Chronic comparisons of Ca 2+ depression magnitude (D), spatial spread (E), and duration (F) across days post-insertion. Mean ± SEM across mice.

Article Snippet: Custom stimulation microelectrodes (Q1×4-3mm-50-703-CM16LP, NeuroNexus Technologies, single 3-mm-long shank, 30-μm-diameter four channels, 50-μm site spacing, electrochemically activated iridium/iridium oxide sites ) were implanted at an angle of 20-30 degrees slanted towards the posterior region.

Techniques:

Journal: bioRxiv

Article Title: Chronic alteration of Ca 2+ and hemodynamic signals induced by intracortical microstimulation in the visual cortex of awake mice

doi: 10.1101/2025.10.23.679242

Figure Lengend Snippet: ( A-C ) Example OEF response colormaps from a single mouse during and after ( A ) 25-Hz ICMS, ( B ) 250-Hz ICMS, and ( C ) visual stimulation at (i and ii) day 0 and (iii and iv) day 21. Corresponding time courses within 500 µm of the stimulation site are shown in (v; mean ± SD across 4 trials). OEF represents deoxyhemoglobin relative to total hemoglobin (see 2.4.4), where decreases from baseline (0.25) indicate relative increases in oxyhemoglobin, reflecting enhanced metabolic supply. ( D-F ) Chronic comparisons of OEF magnitude (D), spatial spread (E), and duration (F) across days post-implantation. Mean ± SEM across mice. * next to line plot indicates a significant effect of day (LME model).

Article Snippet: Custom stimulation microelectrodes (Q1×4-3mm-50-703-CM16LP, NeuroNexus Technologies, single 3-mm-long shank, 30-μm-diameter four channels, 50-μm site spacing, electrochemically activated iridium/iridium oxide sites ) were implanted at an angle of 20-30 degrees slanted towards the posterior region.

Techniques:

Journal: bioRxiv

Article Title: Chronic alteration of Ca 2+ and hemodynamic signals induced by intracortical microstimulation in the visual cortex of awake mice

doi: 10.1101/2025.10.23.679242

Figure Lengend Snippet: ( A ) Example epileptiform Ca 2+ activity induced by 25-Hz ICMS, showing extremely strong activation spreading across the entire visual cortex and persisting >10 s after stimulation offset (i-v, maps; vi, time courses at each distance). ( B ) Overview of Ca 2+ activity induced by 25-Hz ICMS (i), 250-Hz ICMS (ii), and visual stimulation (iii). Each line represents one mouse. ( C ) Distributions of magnitude, duration, and spatial spread of Ca 2+ activation. Colors indicate clusters identified using agglomerative clustering (see Methods). Epileptiform activity was defined from the green cluster with magnitude >100%, duration >20 s, and distance >800 µm. ( D ) Number of mice exhibiting epileptiform activity at least once across all days, conditions, and repeats (Epi) versus not (Norm). ( E ) Probability of epileptiform activity across stimulation conditions for all days, mice, and repeats. ( F ) Probability of epileptiform activity over days for all ICMS and visual stimulation conditions. Mean ± SEM across animals.

Article Snippet: Custom stimulation microelectrodes (Q1×4-3mm-50-703-CM16LP, NeuroNexus Technologies, single 3-mm-long shank, 30-μm-diameter four channels, 50-μm site spacing, electrochemically activated iridium/iridium oxide sites ) were implanted at an angle of 20-30 degrees slanted towards the posterior region.

Techniques: Activity Assay, Activation Assay

Journal: Journal of neurosurgery

Article Title: Intraoperative electrocorticography for physiological research in movement disorders: principles and experience in 200 cases

doi: 10.3171/2015.11.JNS151341

Figure Lengend Snippet: FDA-approved MER Systems and the ECoG recording parameters used

Article Snippet: Intraoperative ECoG Recording Over the course of this study, 3 different FDA-approved clinical microelectrode recording systems were customized by the manufacturer to provide additional channels, the appropriate preamplifiers for ECoG, local field potential (LFP) depth recordings, and electromyography recordings, as well as auxiliary channels (without amplification) for other inputs ( ). table ft1 table-wrap mode="anchored" t5 TABLE 1 caption a7 MER System No. of Available ECoG Channels ECoG Amplification Sampling Rate (Hz) * Band-Pass Filter (Hz) File Format No. of Cases Limitations Guideline 4000 (FHC Inc.) 5 7000 1000–3000 1–500 .apm 85 Built in high-pass filter, limited no. of channels, limited stimulation capability Microguide Pro (Alpha Omega Inc.) † 5 7000 1500–3000 1–500 .map 112 Limited no. of channels, limited stimula- tion capability Neuromega (Alpha Omega Inc.) 112 55 2750 0.075–3500 .mpx 3 NA Open in a separate window NA = not applicable.

Techniques: Amplification, Sampling

Journal: Journal of neurosurgery

Article Title: Intraoperative electrocorticography for physiological research in movement disorders: principles and experience in 200 cases

doi: 10.3171/2015.11.JNS151341

Figure Lengend Snippet: FDA-approved MER Systems and the ECoG recording parameters used

Article Snippet: Intraoperative ECoG Recording Over the course of this study, 3 different FDA-approved clinical microelectrode recording systems were customized by the manufacturer to provide additional channels, the appropriate preamplifiers for ECoG, local field potential (LFP) depth recordings, and electromyography recordings, as well as auxiliary channels (without amplification) for other inputs ( ). table ft1 table-wrap mode="anchored" t5 TABLE 1 caption a7 MER System No. of Available ECoG Channels ECoG Amplification Sampling Rate (Hz) * Band-Pass Filter (Hz) File Format No. of Cases Limitations Guideline 4000 (FHC Inc.) 5 7000 1000–3000 1–500 .apm 85 Built in high-pass filter, limited no. of channels, limited stimulation capability Microguide Pro (Alpha Omega Inc.) † 5 7000 1500–3000 1–500 .map 112 Limited no. of channels, limited stimula- tion capability Neuromega (Alpha Omega Inc.) 112 55 2750 0.075–3500 .mpx 3 NA Open in a separate window NA = not applicable.

Techniques: Amplification, Sampling