Table 3
Light microscopic properties of SCN neurons listed per cell cluster
| Parameter | Cluster I | Cluster II | Cluster III |
|---|---|---|---|
| Number of cells | 21 | 4 | 4 |
| Soma minimum diameter | 10.1 ± 0.6 | 11.8 ± 0.4 | 11.6 ± 0.6 |
| Soma maximum diameter | 14.8 ± 0.8 | 15.4 ± 1.3 | 13.2 ± 1.8 |
| Number of primary dendrites | 1.8 ± 0.1 | 1.8 ± 0.5 | 2.5 ± 0.3 |
| Number of secondary dendrites | 1.2 ± 0.3 | 1.0 ± 0.6 | 1.5 ± 1.0 |
| Number of axon collaterals | 5.1 ± 0.9 | 6.5 ± 2.2 | 11.0 ± 1.2* |
| Percentage of cells with somatic spines | 29 | 50 | 0 |
| Percentage of cells with dendritic spines | 43 | 25 | 75 |
| Percentage of cells projecting outside SCN | 43 | 25 | 75 |
-
Values represent means ±s.e.m. Only cells patch clamped under visual control at 29–31 °C were included; intermediate cases were excluded. Projection axons were included in the number of axon collaterals. Asterisk indicates statistical significance in differences from cluster I (P < 0.02, Mann-Whitney U test).