The Impact of Optical Undersampling on the Ca2+ Signal Resolution in Ca2+ Imaging of Spontaneous Neuronal Activity
Background: In neuroscience, Ca2+ imaging is a prevalent technique used to infer neuronal electrical activity, often relying on optical signals recorded at low sampling rates (3 to 30 Hz) across multiple neurons simultaneously. This study investigated whether increasing the sampli...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IMR Press
2025-01-01
|
| Series: | Journal of Integrative Neuroscience |
| Subjects: | |
| Online Access: | https://www.imrpress.com/journal/JIN/24/1/10.31083/JIN26242 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832586617757368320 |
|---|---|
| author | Katarina D. Milicevic Violetta O. Ivanova Tina N. Brazil Cesar A. Varillas Yan M.D. Zhu Pavle R. Andjus Srdjan D. Antic |
| author_facet | Katarina D. Milicevic Violetta O. Ivanova Tina N. Brazil Cesar A. Varillas Yan M.D. Zhu Pavle R. Andjus Srdjan D. Antic |
| author_sort | Katarina D. Milicevic |
| collection | DOAJ |
| description | Background: In neuroscience, Ca2+ imaging is a prevalent technique used to infer neuronal electrical activity, often relying on optical signals recorded at low sampling rates (3 to 30 Hz) across multiple neurons simultaneously. This study investigated whether increasing the sampling rate preserves critical information that may be missed at slower acquisition speeds. Methods: Primary neuronal cultures were prepared from the cortex of newborn pups. Neurons were loaded with Oregon Green BAPTA-1 AM (OGB1-AM) fluorescent indicator. Spontaneous neuronal activity was recorded at low (14 Hz) and high (500 Hz) sampling rates, and the same neurons (n = 269) were analyzed under both conditions. We compared optical signal amplitude, duration, and frequency. Results: Although recurring Ca2+ transients appeared visually similar at 14 Hz and 500 Hz, quantitative analysis revealed significantly faster rise times and shorter durations (half-widths) at the higher sampling rate. Small-amplitude Ca2+ transients, undetectable at 14 Hz, became evident at 500 Hz, particularly in the neuropil (putative dendrites and axons), but not in nearby cell bodies. Large Ca2+ transients exhibited greater amplitudes and faster temporal dynamics in dendrites compared with somas, potentially due to the higher surface-to-volume ratio of dendrites. In neurons bulk-loaded with OGB1-AM, cell nucleus-mediated signal distortions were observed in every neuron examined (n = 57). Specifically, two regions of interest (ROIs) on different segments of the same cell body displayed significantly different signal amplitudes and durations due to dye accumulation in the nucleus. Conclusions: Our findings reveal that Ca2+ signal undersampling leads to three types of information loss: (1) distortion of rise times and durations for large-amplitude transients, (2) failure to detect small-amplitude transients in cell bodies, and (3) omission of small-amplitude transients in the neuropil. |
| format | Article |
| id | doaj-art-fd9d77807cf748749c97caf01eeaf721 |
| institution | Kabale University |
| issn | 0219-6352 1757-448X |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IMR Press |
| record_format | Article |
| series | Journal of Integrative Neuroscience |
| spelling | doaj-art-fd9d77807cf748749c97caf01eeaf7212025-01-25T07:38:07ZengIMR PressJournal of Integrative Neuroscience0219-63521757-448X2025-01-012412624210.31083/JIN26242S0219-6352(24)00868-4The Impact of Optical Undersampling on the Ca2+ Signal Resolution in Ca2+ Imaging of Spontaneous Neuronal ActivityKatarina D. Milicevic0Violetta O. Ivanova1Tina N. Brazil2Cesar A. Varillas3Yan M.D. Zhu4Pavle R. Andjus5Srdjan D. Antic6Neuroscience Department, University of Connecticut Health, School of Medicine, Institute for Systems Genomics, Farmington, CT 06030, USANeuroscience Department, University of Connecticut Health, School of Medicine, Institute for Systems Genomics, Farmington, CT 06030, USANeuroscience Department, University of Connecticut Health, School of Medicine, Institute for Systems Genomics, Farmington, CT 06030, USANeuroscience Department, University of Connecticut Health, School of Medicine, Institute for Systems Genomics, Farmington, CT 06030, USANeuroscience Department, University of Connecticut Health, School of Medicine, Institute for Systems Genomics, Farmington, CT 06030, USACenter for Laser Microscopy, Institute of Physiology and Biochemistry ‘Jean Giaja’ , Faculty of Biology, University of Belgrade, 11000 Belgrade, SerbiaNeuroscience Department, University of Connecticut Health, School of Medicine, Institute for Systems Genomics, Farmington, CT 06030, USABackground: In neuroscience, Ca2+ imaging is a prevalent technique used to infer neuronal electrical activity, often relying on optical signals recorded at low sampling rates (3 to 30 Hz) across multiple neurons simultaneously. This study investigated whether increasing the sampling rate preserves critical information that may be missed at slower acquisition speeds. Methods: Primary neuronal cultures were prepared from the cortex of newborn pups. Neurons were loaded with Oregon Green BAPTA-1 AM (OGB1-AM) fluorescent indicator. Spontaneous neuronal activity was recorded at low (14 Hz) and high (500 Hz) sampling rates, and the same neurons (n = 269) were analyzed under both conditions. We compared optical signal amplitude, duration, and frequency. Results: Although recurring Ca2+ transients appeared visually similar at 14 Hz and 500 Hz, quantitative analysis revealed significantly faster rise times and shorter durations (half-widths) at the higher sampling rate. Small-amplitude Ca2+ transients, undetectable at 14 Hz, became evident at 500 Hz, particularly in the neuropil (putative dendrites and axons), but not in nearby cell bodies. Large Ca2+ transients exhibited greater amplitudes and faster temporal dynamics in dendrites compared with somas, potentially due to the higher surface-to-volume ratio of dendrites. In neurons bulk-loaded with OGB1-AM, cell nucleus-mediated signal distortions were observed in every neuron examined (n = 57). Specifically, two regions of interest (ROIs) on different segments of the same cell body displayed significantly different signal amplitudes and durations due to dye accumulation in the nucleus. Conclusions: Our findings reveal that Ca2+ signal undersampling leads to three types of information loss: (1) distortion of rise times and durations for large-amplitude transients, (2) failure to detect small-amplitude transients in cell bodies, and (3) omission of small-amplitude transients in the neuropil.https://www.imrpress.com/journal/JIN/24/1/10.31083/JIN26242intracellular calciumneuropildendritescell nucleussignal distortionwide-field imaginghigh-speed imagingccd camera |
| spellingShingle | Katarina D. Milicevic Violetta O. Ivanova Tina N. Brazil Cesar A. Varillas Yan M.D. Zhu Pavle R. Andjus Srdjan D. Antic The Impact of Optical Undersampling on the Ca2+ Signal Resolution in Ca2+ Imaging of Spontaneous Neuronal Activity Journal of Integrative Neuroscience intracellular calcium neuropil dendrites cell nucleus signal distortion wide-field imaging high-speed imaging ccd camera |
| title | The Impact of Optical Undersampling on the Ca2+ Signal Resolution in Ca2+ Imaging of Spontaneous Neuronal Activity |
| title_full | The Impact of Optical Undersampling on the Ca2+ Signal Resolution in Ca2+ Imaging of Spontaneous Neuronal Activity |
| title_fullStr | The Impact of Optical Undersampling on the Ca2+ Signal Resolution in Ca2+ Imaging of Spontaneous Neuronal Activity |
| title_full_unstemmed | The Impact of Optical Undersampling on the Ca2+ Signal Resolution in Ca2+ Imaging of Spontaneous Neuronal Activity |
| title_short | The Impact of Optical Undersampling on the Ca2+ Signal Resolution in Ca2+ Imaging of Spontaneous Neuronal Activity |
| title_sort | impact of optical undersampling on the ca2 signal resolution in ca2 imaging of spontaneous neuronal activity |
| topic | intracellular calcium neuropil dendrites cell nucleus signal distortion wide-field imaging high-speed imaging ccd camera |
| url | https://www.imrpress.com/journal/JIN/24/1/10.31083/JIN26242 |
| work_keys_str_mv | AT katarinadmilicevic theimpactofopticalundersamplingontheca2signalresolutioninca2imagingofspontaneousneuronalactivity AT violettaoivanova theimpactofopticalundersamplingontheca2signalresolutioninca2imagingofspontaneousneuronalactivity AT tinanbrazil theimpactofopticalundersamplingontheca2signalresolutioninca2imagingofspontaneousneuronalactivity AT cesaravarillas theimpactofopticalundersamplingontheca2signalresolutioninca2imagingofspontaneousneuronalactivity AT yanmdzhu theimpactofopticalundersamplingontheca2signalresolutioninca2imagingofspontaneousneuronalactivity AT pavlerandjus theimpactofopticalundersamplingontheca2signalresolutioninca2imagingofspontaneousneuronalactivity AT srdjandantic theimpactofopticalundersamplingontheca2signalresolutioninca2imagingofspontaneousneuronalactivity AT katarinadmilicevic impactofopticalundersamplingontheca2signalresolutioninca2imagingofspontaneousneuronalactivity AT violettaoivanova impactofopticalundersamplingontheca2signalresolutioninca2imagingofspontaneousneuronalactivity AT tinanbrazil impactofopticalundersamplingontheca2signalresolutioninca2imagingofspontaneousneuronalactivity AT cesaravarillas impactofopticalundersamplingontheca2signalresolutioninca2imagingofspontaneousneuronalactivity AT yanmdzhu impactofopticalundersamplingontheca2signalresolutioninca2imagingofspontaneousneuronalactivity AT pavlerandjus impactofopticalundersamplingontheca2signalresolutioninca2imagingofspontaneousneuronalactivity AT srdjandantic impactofopticalundersamplingontheca2signalresolutioninca2imagingofspontaneousneuronalactivity |