Table 1. Summary of the principal morphological and electrophysiological characteristics that differentiate retinal OFF bipolar cells in rat.
| Characteristics | BC-1 | BC-2 | BC-2′ | BC-3a | BC-3b | BC-4 |
|---|---|---|---|---|---|---|
| Dendritic arbour width (μm) | 29 ± 2 (n = 6) | 14 ± 1 (n = 29) | 13 ± 2 (n = 7) | 15 ± 0.4 (n = 89) | 13 ± 1 (n = 48) | 11 ± 0.3 (n = 91) |
| Axon arbour width (μm) | 13 ± 1 (n = 6) | 26 ± 1 (n = 30) | 35 ± 3 (n = 8) | 20 ± 0.4 (n = 90) | 18 ± 0.5 (n = 53) | 17 ± 0.3 (n = 101) |
| Axon ending depth in IPL (%) | 19 ± 2 (n = 6) | 24 ± 1 (n = 30) | 27 ± 1 (n = 8) | 40 ± 0.3 (n = 90) | 41 ± 0.3 (n = 53) | 31 ± 0.3 (n = 101) |
| Max outward current (pA) | 803 ± 92 (n = 5) | 875 ± 51 (n = 28) | 553 ± 61 (n = 8) | 617 ± 15 (n = 90) | 742 ± 19 (n = 76) | 778 ± 24 (n = 74) |
| Max sodium current (pA) | — | — | 214 ± 35 (n = 8) | 115 ± 14 (n = 18) | — | — |
| Max calcium current* (pA) | nd | 67 ± 12 (n = 3) | nd | 20 ± 9 (n = 3) | 53 ± 12 (n = 3) | 52 ± 18 (n = 4) |
| Max HCN current (pA) | — | 45 ± 4 (n = 16) | 60 ± 11 (n = 7) | 82 ± 2 (n = 33) | — | — |
| Glu response charge (pC) | 64 ± 19 (n = 3) | 99 ± 10 (n = 14) | 147 ± 31 (n = 5) | 20 ± 2 (n = 50) | 71 ± 7 (n = 27) | 318 ± 19 (n = 46) |
| Glu response Imax (pA) | 18 ± 10 (n = 3) | 12 ± 2 (n = 14) | 14 ± 4 (n = 5) | 78 ± 5 (n = 50) | 83 ± 10 (n = 27) | 82 ± 5 (n = 46) |
| Glu response time-to-peak (ms) | 546 ± 93 (n = 3) | 479 ± 48 (n = 14) | 474 ± 76 (n = 5) | 115 ± 8 (n = 50) | 91 ± 7 (n = 27) | 108 ± 8 (n = 46) |
| GYKI blockage (% charge) | nd | 59 ± 14 (n = 3) | nd | 2 ± 2 (n = 5) | 31 ± 9 (n = 3) | 54 ± 8 (n = 5) |
| SYM blockage (% charge) | nd | 30 ± 16 (n = 3) | nd | 94 ± 2 (n = 3) | 66 ± 14 (n = 3) | 47 ± 11 (n = 5) |
| UBP blockage (% charge) | nd | nd | nd | 89 ± 4 (n = 3) | nd | 27 ± 15 (n = 5) |
Values indicate the mean ± s.e.m. nd, not determined; —, undetectable. *Under blockage of K+ currents.