, Stuttering neurons in the CeL. , Stuttering neurons in the CeL. A, Example trace of firing of a stuttering (S) neuron at threshold, and twice and three times threshold. In addition to its fast AP kinetics (Table 1) and distinct firing pattern, large fast afterhyperpolarizations (as indicated by the red arrowhead) are also typical of this firing type. Inset shows a closeup of a spontaneous EPSP (sEPSP) in green. B, Overlay of the first AP of a stuttering (red), LF-NA (black), and ES-Ac (blue) neurons. The AP rise time and half-width of S neurons were significantly faster than those of LF-NA and ES-Ac neurons (Table 1). C, sEPSPs in S neurons were significantly more numerous than in LF-NA and ES-Ac neurons during the hyperpolarizing steps of this protocol. Numbers shown are the total counted over the −60, −40, and −20 pA current injections (B; S vs LF-NA: p = 0.001, unpaired t test; S vs ES-Ac: p < 0.0001, unpaired t test). D, Example biocytin recovery of an S neuron, which was PKCδ(−) (top inset, yellow arrowhead indicates the soma of the S neuron). Scale bars: 20 µm; top inset, 10 µm; bottom inset, 5 µm. This neuron displayed an extensive axon with inset showing a closeup of the axon in the dotted white square. E, Percentage of firing types for recovered neurons that were PKCδ(+) (n = 8) or PKCδ(−) (n = 17). F, Shows total percentage of each firing type. Sarah Hunt et al. eNeuro 2017;4:ENEURO.0367-16.2017 ©2017 by Society for Neuroscience