Table 3.

Summary of the phenotypic differences between X94 and X98 neurons

Phenotypic propertyX94X98
Cell body positionLayers 4 and 5BLayers 5B and 6
Layer 4 axonal arborizationsDenseNone or sparse
Layer 1 axonal arborizationsNone or sparseDense
Neuropeptide YNone∼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.