On the other hand, the slow hyperpolarization that follows a spike train (sAHP), which in CA1 pyramidal cells is largely mediated by KCa3.1 subunits (King et al., 2015), is also significantly reduced in the UBQLN2P497H mice, but this reduction appears to be largely the consequence of the reduced maximum firing frequency and, consequently, the reduced number of spikes within each prolonged AP train in ALS mice, as it only appears when significant differences in firing frequency are detectable. This evidence concerns the gene KCNN4 and amyotrophic lateral sclerosis.