Table 1.
Summary of early and late HOC effects and associated AQP4 and/or VRAC supporting roles.
| Effect | Supporting Role | Effect | Supporting Role | |||||
|---|---|---|---|---|---|---|---|---|
| Measurements | Figure | Early HOC | AQP4 | VRAC | Late HOC |
AQP4 | VRAC | |
| Acute Slice | Firing rate | Figure 1 and Figure 2 | ↓ | Y | Y | R | Y | Y |
| sEPSC frequency | Figure 3 | ↓ | Y | Y | ↓ | N | Y | |
| GVP/TVP | Figure 4 | ↑ | NT | N | R | NT | Y | |
| AQP4 intensity/level | Figure 4 | ↑ | NT | Y | R, t | NT | ND-t | |
| GFAP-AQP4 MCC | Figure 4 | ↑, t | NT | ND-t | R | NT | Y | |
| LRRC8A intensity/level | Figure 5 | ↑ | Y | NT | ↑ | N | NT | |
| GFAP-LRRC8A MCC | Figure 5 | ↑ | Y | NT | R, t | ND-t | NT | |
| Astro Culture | VRAC current | Figure 6 and Figure 7 | NC | NA | NA | ↑ | N; Y-pt | Y |
| ∆V/V0 | Figure 8 | ↑ | Y | N | RVD | Y | Y | |
| GFAP filament length | Figure 9 | ↑ | Y | N | R | Y | Y | |
| LRRC8A intensity/level | Figure 9 | ↑ | Y | Y | R | Y | N | |
| GFAP-LRRC8A MCC | Figure 9 | ↑, t | ND-t | ND-t | ↓ | Y | Y | |
NB: early HOC refers to 5 min in acute slices and 1.5 min in cultured astrocytes; late HOC refers to 10 min in acute slices and 5 min in cultured astrocytes. Abbreviations of table entries/symbols: N, no; NA, not applicable; NC, no change; ND-t, not determined due to a trend in an HOC effect; NT, not tested; pt, pretreatment; R, rebound, retraction, or reversal decrease/subside; RVD, regulatory volume decrease; t, trend; Y, yes; ↓, decrease; ↑, increase. Abbreviations of terms: AQP4, aquaporin 4; Astro, astrocyte; GFAP, glial fibrillary acidic protein; GVP, VP neuronal somata surrounded by GFAP filaments; HOC, hyposmotic challenge; LRRC8A, leucine-rich repeat-containing protein 8 A; MCC, Manders’ colocalization coefficient; sEPSC, spontaneous excitatory postsynaptic current; VRAC, volume-regulated anion channel; TVP, total number of VP neurons; △V/V0, relative volume change.