Table 4.
Lateral mobility of P2X2FLAG–YFP receptors in neuronal dendrites and HEK-293 cells in relation to P2X4HA–YFP receptors in neurons
| Basal mobility in unpatched cells |
ATP-evoked responses in patched cells |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mobile |
Slowly mobile |
|||||||||||
| D (μm2/s) | Area (μm2) | Qds | D (×10−4 μm2/s) | Area (μm2) | Qds | Dapp without ATP (μm2/s) | Dapp with ATP (μm2/s) | p* | Qds (n) | IATP (pA/pF) | Cells (n) | |
| P2X2FLAG–YFP in neurons | 0.027 ± 0.0026 | 1.2 ± 0.06 | n = 460 (70%) | 2.8 ± 0.2 | 0.08 ± 0.004 | n = 198 (30%) | 0.012 ± 0.002 | 0.027 ± 0.004 | <0.01 | 169 | −97 ± 7 | 37 |
| P2X2FLAG–YFP in HEK-293 cells | 0.0015 ± 0.0003 | 0.18 ± 0.017 | n = 114 (100%) | ND | ND | 0.011 ± 0.0034 | 0.0076 ± 0.0022 | 0.1 | 31 | −49 ± 9 | 12 | |
| P2X4HA–YFP in neurons | 0.032 ± 0.0033 | 1.3 ± 0.1 | n = 124 (75%) | 2.3 ± 0.41 | 0.12 ± 0.001** | n = 42 (25%) | 0.014 ± 0.0047 | 0.017 ± 0.0057 | 0.4 | 66 | −90 ± 8 | 16 |
The values for D indicated as basal mobility are only shown for the trajectories that were linear, as described in Results. * indicates p values for paired t test between without-ATP and with-ATP conditions for measurements of apparent diffusion coefficient Dapp for the experiments indicated (see Results). Area refers to area of the trajectory measured for 30 s imaging experiments as described in Results. ** indicates that the trajectory area for the slowly mobile P2X4HA–YFP receptors was significantly greater than the corresponding value for P2X2FLAG–YFP receptors (p < 0.01). ND indicates not determined because, in the case of P2X2FLAG–YFP receptors expressed in HEK-293 cells, the distribution of D was unimodal with a single value shown as the mobile pool, which was significantly smaller than the corresponding value for D in neurons.