Table 1.
Summary of electrophysiological and morphological properties in medial and lateral superior colliculus at P6–7
| Property | Medial SC (binocular) | Lateral SC (predominantly monocular) | Relative Difference (medial vs. lateral) | P Value |
|---|---|---|---|---|
| Quantal AMPA current amplitude, pA | 21.31 ± 0.86 (n = 11) | 18.15 ± 0.75 (n = 7) | +17% | 0.021* |
| NMDA decay time constant, ms | 176 ± 23 (n = 14) | 302 ± 32 (n = 11) | −42% | 0.0032† |
| AMPA-to-NMDA current ratio | 1.82 ± 0.18 (n = 14) | 1.54 ± 0.16 (n = 11) | +18% | 0.27 |
| NMDA single-fiber response amplitude, pA | 14.46 ± 1.15 (n = 10) | 10.23 ± 0.73 (n = 8) | +41% | 0.0098† |
| NMDA saturation response amplitude, pA | 59.90 ± 8.38 (n = 10) | 43.19 ± 7.87 (n = 8) | +39% | 0.17 |
| Number of retinal inputs | 4.31 ± 0.66 (n = 10) | 4.18 ± 0.68 (n = 8) | +3% | 0.89 |
| Input resistance, Ω | 1213 ± 169 (n = 28) | 1078 ± 152 (n = 18) | +12% | 0.58 |
| Number of dendritic nodes | 60.2 ± 12.5 (n = 10) | 26.8 ± 2.7 (n = 9) | +125% | 0.023* |
| Fractal dimensions of dendritic tree | 1.089 ± 0.017 (n = 10) | 1.059 ± 0.008 (n = 9) | +3% | 0.129 |
| Dendritic length, μm | 2203 ± 357 (n = 10) | 1445 ± 213 (n = 9) | +52% | 0.094 |
Data are presented as means ± SE. SC, superior colliculus. Percent difference between the slices defined as 100·(xm − xL)/xL, where xm and xL are the corresponding values in the medial and lateral slices, respectively. Differences in means tested with a 2-tailed Student's t-test: *P < 0.05,
†
P < 0.01. Synaptic/morphological properties that differed significantly between the 2 slices are in boldface.