{
"papers": [
{
"n": 106,
"doi": "10.1016/j.neuron.2014.04.038",
"value": "1.4 ± 0.1 s",
"method": "two-photon in vivo Ca2+ imaging",
"metric": "onset latency of astrocyte Ca2+ transient after locomotion onset",
"n_analyzed": "106 locomotion events from 13 mice",
"ci_or_error": "± 0.1 s SEM",
"text_access": "fulltext",
"n_definition": "locomotion events pooled across animals",
"scope_region": "visual cortex + cerebellum",
"study_system": "mouse; in vivo two-photon; visual cortex and cerebellum Bergmann glia; awake head-fixed on treadmill",
"taxonomic_level": "broad class",
"scope_population": "astrocytes (cortical + Bergmann glia)",
"value_source_sentence": "In contrast to neuronal activation, which began within 50 ms of locomotion onset, Ca 2+ transients in astrocytes began more than a second later (1.4 ± 0.1 s, n = 106 events from 13 mice), presumably reflecting the additional biochemical steps required to release Ca 2+ from intracellular stores.",
"experimental_conditions": "voluntary locomotion, darkness; GCaMP3 expressed via GLAST-CreER"
},
{
"n": 93,
"doi": "10.1016/j.neuron.2009.03.019",
"value": "4.4 ± 2.5 s",
"method": "two-photon in vivo Ca2+ imaging with OGB-1 AM",
"metric": "Ca2+ flare peak latency after locomotion reinitiation",
"n_analyzed": "93 flare events from 15 mice",
"ci_or_error": "± 2.5 s SD",
"text_access": "fulltext",
"n_definition": "flare events pooled across animals",
"scope_region": "cerebellar vermis",
"study_system": "mouse; in vivo two-photon; cerebellar vermis Bergmann glia; awake head-fixed on exercise ball",
"taxonomic_level": "subtype",
"scope_population": "Bergmann glia (radial glia)",
"value_source_sentence": "If >10 s had elapsed since termination of the prior locomotor episode, flares reached peak fluorescence 4.4 ± 2.5 s after reinitiation of movement (n = 93 events, 15 mice) ( Figure 6 C).",
"experimental_conditions": "voluntary locomotion, following >10 s rest; OGB1-AM bulk loading"
},
{
"n": 0,
"doi": "10.1016/j.neuron.2018.03.050",
"value": "588.5 ± 21.2 ms",
"method": "two-photon in vivo Ca2+ imaging, frame + line-scan",
"metric": "onset latency of fast astrocyte microdomains (MDs) after sensory stimulus",
"n_analyzed": "events pooled across animals (n not reported in this sentence)",
"ci_or_error": "± 21.2 ms SEM",
"text_access": "fulltext",
"n_definition": "Ca2+ microdomain events",
"scope_region": "somatosensory cortex",
"study_system": "mouse; in vivo two-photon; somatosensory cortex; awake head-fixed",
"taxonomic_level": "fine compartment",
"scope_population": "astrocyte fine processes (microdomains)",
"value_source_sentence": "Fast MDs had a peak onset latency on a similar scale to neurons (mean neuronal onset = 270.7 ± 4.3 ms; mean fast MDs onset = 588.5 ± 21.2 ms; mean delayed MDs onset = 5.45 ± 0.05 s; Figure 2 E).",
"experimental_conditions": "sensory stimulation; GCaMP6f in astrocytes"
},
{
"n": 0,
"doi": "10.1038/s41467-020-17062-2",
"value": "1–2 s before",
"method": "two-photon + polysomnography",
"metric": "time astrocyte Ca2+ increase precedes sleep→wake transition",
"n_analyzed": "NREM→wake (60%) and IS→wake (72%) transitions",
"ci_or_error": "range 1–2 s",
"text_access": "fulltext",
"n_definition": "sleep–wake transition events",
"scope_region": "somatosensory cortex",
"study_system": "mouse; in vivo two-photon; somatosensory cortex; head-fixed",
"taxonomic_level": "broad class",
"scope_population": "all cortical astrocytes (Lck-GCaMP6f)",
"value_source_sentence": "We observed a prominent increase in astrocytic Ca 2+ signal frequency 1–2 s before the shift in ECoG, EMG, and mouse movement in 60% of NREM sleep to wakefulness and 72% of IS sleep to wakefulness transitions (Fig.",
"experimental_conditions": "natural sleep-wake; Lck-GCaMP6f in cortical astrocytes; ECoG + EMG"
}
],
"comparison_id": "locomotion-ca-timing-across-regions",
"comparison_name": "Locomotion-evoked astrocyte Ca2+ transient timing across cerebellum and cortex",
"comparison_type": "cross-study convergent evidence with timescale contrast",
"what_it_reveals": "Astrocyte Ca2+ responses to locomotion or state transitions span three orders of magnitude in timing: sub-second fast microdomains (Stobart 2018), ~1–2 s population latencies in cortex during locomotion or state switches (Paukert 2014; Bojarskaite 2020), to multi-second flare peaks in Bergmann glia following extended rest (Nimmerjahn 2009). This challenges the textbook claim that astrocyte Ca2+ is uniformly slow and suggests distinct subcellular compartments operate on different timescales.",
"homogeneity_check": {
"caveats": [
"Regions differ: cerebellar Bergmann glia (Nimmerjahn 2009) vs. visual cortex + cerebellum (Paukert 2014) vs. somatosensory cortex (Stobart 2018, Bojarskaite 2020).",
"Indicator differs: OGB1-AM bulk loading (Nimmerjahn 2009) vs. GCaMP3 (Paukert 2014) vs. GCaMP6f with line scan (Stobart 2018) vs. Lck-GCaMP6f (Bojarskaite 2020) — the progression of sensitivity/kinetics directly affects detectable event classes.",
"Spatial scale: Paukert/Nimmerjahn report soma/population events; Stobart reports fine-process microdomains; Bojarskaite reports membrane-targeted Lck signals. A whole-cell soma measurement and a process microdomain measurement should not be treated as equivalent observations.",
"Stimulus differs: spontaneous locomotion (Nimmerjahn, Paukert, Bojarskaite) vs. sensory stimulation triggering fast MDs (Stobart).",
"The Nimmerjahn n=93 is events pooled across 15 mice; Paukert n=106 from 13 mice; Stobart sentence does not report n for the 588.5 ms value in the source sentence cited; Bojarskaite reports percentages of transitions rather than a pooled n."
],
"n_definition_uniform": "false",
"scope_region_uniform": "false",
"taxonomic_level_uniform": "false",
"scope_population_uniform": "false"
},
"suggested_plot_type": "forest plot with log-scale x-axis of latency"
}