Table 1.
Developmental comparison of neuronal properties, motor patterns, and behavior
| 2-d-old embryos |
4-d-old larvae |
|||||
|---|---|---|---|---|---|---|
| Mean | SD | n | Mean | SD | n | |
| Head yaw (degrees) | ||||||
| <40 Hz | 46.1 | 6.7 | 5 | 5.7* | 1.9 | 5 |
| >40 Hz | 59.5 | 3.4 | 5 | 53.4 | 3.4 | 5 |
| Tail yaw (degrees) | ||||||
| <40 Hz | 59.2 | 8.0 | 5 | 65.7 | 5.9 | 5 |
| >40 Hz | 74.4 | 11.1 | 5 | 107.4* | 6.9 | 5 |
| Motor burst durations (ms) | ||||||
| <40 Hz | 3.5 | 1.3 | 10 | 11.2* | 1.7 | 10 |
| >40 Hz | 3.1 | 1.0 | 10 | 4.8 | 0.8 | 10 |
| Spike number (per cycle) | ||||||
| Primary motoneurons | 1.23* | 0.19 | 15 | 2.72* | 0.84 | 15 |
| Secondary motoneurons | 1.12* | 0.19 | 30 | 3.09* | 1.83 | 30 |
| Rhythmic CiDs | 1.21* | 0.17 | 20 | 2.76* | 1.00 | 36 |
| D-V position (normalized) | ||||||
| Primary motoneurons | 0.48* | 0.04 | 15 | 0.56* | 0.04 | 15 |
| Displaced CiDs | 0.68* | 0.05 | 15 | 0.75* | 0.05 | 15 |
| Soma size (μm2) | ||||||
| Primary motoneurons | 51.1* | 6.1 | 15 | 76.5* | 17.8 | 15 |
| Displaced CiDs | 32.9* | 4.2 | 15 | 26.2* | 4.2 | 15 |
| Input resistance (MΩ) | ||||||
| Primary motoneurons | 267.3* | 94.1 | 15 | 160.3* | 69.2 | 15 |
| Displaced CiDs | 621.1 | 120.3 | 15 | 708.5 | 159.2 | 15 |
Data are reported as the mean, the SD, and the number (n) of animals. Asterisks for yaw data indicate values that are significantly different from all other means for the same body region (head or tail). The others in the same category showed no differences from one another. Similarly, the asterisk for motor burst duration is the only value that was significantly different from all of the other durations. Asterisks for other measures indicate a significant difference between embryonic and larval values for that cell type. Data for 4-d-old larvae analyzed and tabulated here include data originally collected for other work (McLean et al., 2007, 2008). See Materials and Methods for details. D-V, Dorsoventral.