Table 1.
Brain pericyte contractility. A survey of data assessing whether pericytes covering the brain vasculature are able to contract and relax and over what timescale contractile operations occur
| Branch order | Cell type | Reference | Preparation | Contractile stimulus | Diameter change (% versus baseline) | Onset time (time to peak) |
|---|---|---|---|---|---|---|
| 0 | SMCs | 180 | Parenchymal arteriole myography; mouse | Physiological pressure U46619 Caffeine | Constriction | Seconds |
| 181 | Parenchymal arteriole myography; rat | Physiological pressure NOS block | Constriction | No data | ||
| 182 | Parenchymal arteriole myography; mouse | Physiological pressure Purines | Constriction | Seconds | ||
| 56 | In vivo cranial window | Optogenetic activation of ChR2 | Constriction (40%) | Seconds (~25 s) | ||
| 45 | In vivo cranial window | Optogenetic activation of ChR2 | Constriction (~20%) | <1 s (> 15 s) | ||
| Sensory stimulation | Dilation (~10%) | ~2 s (~40 s) | ||||
| 49 | In vivo cranial window | Sensory stimulation | Dilation (~11%) | ~1 s (~18 s) | ||
| 183 | In vivo cranial window | Sensory stimulation | Dilation (~15%) | ~1 s (~5 s) | ||
| 52 | In vivo cranial window | Sensory stimulation | Dilation (~10%) | ~3 s (~12 s) | ||
| 1 | Contractile pericytes | 49 | In vivo cranial window | 500 mM K+ | Constriction (~25%) | Seconds (30 s) |
| Sensory stimulation | Dilation (~16%) | ~ 1 s (~ 15 s) | ||||
| 183 | In vivo cranial window; vessels <50 μm from PA | Sensory stimulation | Dilation (~30%) | ~ 1 s (~4 s) | ||
| 52 | In vivo cranial window | Sensory stimulation | Dilation (~14%) | ~ 1 s (~6 s) | ||
| 1–4 | Contractile pericytes | 183 | In vivo cranial window; vessels >50 μm from PA | Sensory stimulation | Dilation (10%) | ~1 s (~5 s) |
| 45 | In vivo cranial window | Optogenetic activation of ChR2 | Constriction (~ 12%) | <1 s (> 15 s) | ||
| Sensory stimulation (vessels with α-actin) | Dilation (~10%) | ~2 s (~40 s) | ||||
| 56 | In vivo cranial window | Optogenetic activation of ChR2 | Constriction (20%) | Seconds (>1 min) | ||
| 5+ | Thin-strand pericytes | 56 | In vivo cranial window | Optogenetic activation of ChR2 | Constriction (19%) | Seconds (>1 min) |
| 111 | Acute brain slices | U46619 | Constriction (25%) | Seconds (>2 min) | ||
| In vivo cranial window | U46619 | Constriction (17%) | No data | |||
| Sensory stimulation | No change | Not applicable | ||||
| 183 | In vivo cranial window | Sensory stimulation | No change | Not applicable |
Abbreviations: ChR2, channel rhodopsin 2; K+, potassium; NOS, nitric oxide synthase; PA, penetrating arteriole; SMC, smooth muscle cell.