Amplitudes, frequencies, and occupancies of closed and open levels
| Event amplitudes, frequencies, and occupancies . | CTZ n = 7 . | CII n = 5 . | (R, R)-2b n = 3 . | CII + (R, R)-2b n = 6 . |
|---|---|---|---|---|
| Closed | ||||
| Amplitude (pA) | — | — | — | — |
| Frequency of visit | 8 ± 2% | 22 ± 4% | 2 ± 1% | 20 ± 5% |
| Fraction occupied | 12 ± 4% | 27 ± 7% | 3 ± 2% | 40 ± 12% |
| Open 1 | ||||
| Amplitude (pA) | −0.67 ± 0.04 | −0.59 ± 0.01 | −0.64 ± 0.06 | −0.64 ± 0.04 |
| Frequency of visit | 21 ± 5% | 30 ± 4% | 10 ± 6% | 31 ± 5% |
| Fraction occupied | 20 ± 5% | 30 ± 6% | 8 ± 6% | 22 ± 4% |
| Open 2 | ||||
| Amplitude (pA) | −1.3 ± 0.1 | −1.2 ± 0.02 | −1.3 ± 0.1 | −1.3 ± 0.1 |
| Frequency of visit | 28 ± 4% | 25 ± 2% | 22 ± 6% | 28 ± 5% |
| Fraction occupied | 27 ± 6% | 22 ± 3% | 20 ± 9% | 20 ± 5% |
| Open 3 | ||||
| Amplitude (pA) | −2.0 ± 0.1 | −1.75 ± 0.04 | −1.9 ± 0.2 | −1.9 ± 0.1 |
| Frequency of visit | 27 ± 4% | 17 ± 3% | 37 ± 4% | 15 ± 4% |
| Fraction occupied | 19 ± 2% | 14 ± 3% | 28 ± 1% | 13 ± 4% |
| Open 4 | ||||
| Amplitude (pA) | −2.7 ± 0.2 | −2.3 ± 0.1 | −2.7 ± 0.2 | −2.6 ± 0.2 |
| Frequency of visit | 16 ± 6% | 6 ± 3% | 29 ± 9% | 5 ± 3% |
| Fraction occupied | 21 ± 9% | 6 ± 4% | 41 ± 16% | 5 ± 3% |
| Event amplitudes, frequencies, and occupancies . | CTZ n = 7 . | CII n = 5 . | (R, R)-2b n = 3 . | CII + (R, R)-2b n = 6 . |
|---|---|---|---|---|
| Closed | ||||
| Amplitude (pA) | — | — | — | — |
| Frequency of visit | 8 ± 2% | 22 ± 4% | 2 ± 1% | 20 ± 5% |
| Fraction occupied | 12 ± 4% | 27 ± 7% | 3 ± 2% | 40 ± 12% |
| Open 1 | ||||
| Amplitude (pA) | −0.67 ± 0.04 | −0.59 ± 0.01 | −0.64 ± 0.06 | −0.64 ± 0.04 |
| Frequency of visit | 21 ± 5% | 30 ± 4% | 10 ± 6% | 31 ± 5% |
| Fraction occupied | 20 ± 5% | 30 ± 6% | 8 ± 6% | 22 ± 4% |
| Open 2 | ||||
| Amplitude (pA) | −1.3 ± 0.1 | −1.2 ± 0.02 | −1.3 ± 0.1 | −1.3 ± 0.1 |
| Frequency of visit | 28 ± 4% | 25 ± 2% | 22 ± 6% | 28 ± 5% |
| Fraction occupied | 27 ± 6% | 22 ± 3% | 20 ± 9% | 20 ± 5% |
| Open 3 | ||||
| Amplitude (pA) | −2.0 ± 0.1 | −1.75 ± 0.04 | −1.9 ± 0.2 | −1.9 ± 0.1 |
| Frequency of visit | 27 ± 4% | 17 ± 3% | 37 ± 4% | 15 ± 4% |
| Fraction occupied | 19 ± 2% | 14 ± 3% | 28 ± 1% | 13 ± 4% |
| Open 4 | ||||
| Amplitude (pA) | −2.7 ± 0.2 | −2.3 ± 0.1 | −2.7 ± 0.2 | −2.6 ± 0.2 |
| Frequency of visit | 16 ± 6% | 6 ± 3% | 29 ± 9% | 5 ± 3% |
| Fraction occupied | 21 ± 9% | 6 ± 4% | 41 ± 16% | 5 ± 3% |
Idealization of single-channel recordings of GluA2 wild type receptors in glutamate (10 mM) and CTZ (100 μM), CII toxin (100–500 nM), (R, R)-2b (10 μM), or CII + (R, R)-2b, resulted in four open levels for each condition (Open 1–4). Open level amplitudes did not depend on the type of positive allosteric modulator used. Frequencies of visiting each level are expressed as a percentage of the total events and occupancies are expressed as a percentage of the total time the channel spent at a specific level. Number of patches for each condition (n) is indicated.