We assessed HDAC4 localization and nerve swellings in three seizure mutants defective for K+ homeostasis; NCKXzydeco (zyd) which disrupts a K+-dependent Na+/Ca2+ exchanger [17,18], Seizure (SeiTS1) which disrupts an H-type voltage-gated K+ channel [19,20], and a model of dup15q syndrome in which glial overexpression of the ubiquitin ligase and human disease gene ube3a leads to degradation of the Na+/K+ ATPase pump [21,22]. Here, UBE3A is linked to Seizure.