Summary of the phenotypic differences between X94 and X98 neurons
| Phenotypic property | X94 | X98 |
|---|---|---|
| Cell body position | Layers 4 and 5B | Layers 5B and 6 |
| Layer 4 axonal arborizations | Dense | None or sparse |
| Layer 1 axonal arborizations | None or sparse | Dense |
| Somatostatin | All | All |
| Calbindin | None | All |
| Neuropeptide Y | None | ∼40% |
| Input resistance | <250 MΩ | >300 MΩ |
| Time constant | <20 ms | >20 ms |
| Spike width | ≤0.5 ms | ≥0.6 ms |
| Fmax, initial | >200 Hz | <200 Hz |
| Fmax, steady-state | >100 Hz | <100 Hz |
| Robust stuttering | ∼60% | ∼3% |
| Low-threshold spikes | ∼2% | ∼40% |
Phenotypic properties are arranged in five groups: laminar position, axonal distributions, neurochemical content, electrophysiological parameters, and firing properties. Inequalities in the electrophysiological parameters group apply to at least 90% of each population.