Cognitive deficits and impaired hippocampal long-term potentiation in K-induced DEND syndrome.

ATP-sensitive potassium (K) gain-of-function (GOF) mutations cause neonatal diabetes, with some individuals exhibiting developmental delay, epilepsy, and neonatal diabetes (DEND) syndrome. Mice expressing K-GOF mutations pan-neuronally (nK-GOF) demonstrated sensorimotor and cognitive deficits, whereas hippocampus-specific hK-GOF mice exhibited mostly learning and memory deficiencies. Both nK-GOF and hK-GOF mice showed altered neuronal excitability and reduced hippocampal long-term potentiation (LTP). Sulfonylurea therapy, which inhibits K, mildly improved sensorimotor but not cognitive deficits in K-GOF mice. Mice expressing K-GOF mutations in pancreatic β-cells developed severe diabetes but did not show learning and memory deficits, suggesting neuronal K-GOF as promoting these features. These findings suggest a possible origin of cognitive dysfunction in DEND and the need for novel drugs to treat neurological features induced by neuronal K-GOF.