Potassium channels and the development of arousal-relevant action potential trains in primary hindbrain neurons

The KCNB2 gene and its role in neurodevelopmental disorders: Implications for genetics and therapeutic advances

Neurodevelopmental disorders (NDDs) are increasingly linked to genetic mutations that disrupt key neuronal processes. The KCNB2 gene encodes a crucial component of voltage-gated potassium channels, essential for regulating neuronal excitability and synaptic transmission. Mutations in KCNB2 typically alter potassium channel inactivation, leading to various NDDs, including autism spectrum disorders (ASD), intellectual disabilities (ID), and epilepsy. This narrative review synthesizes findings from genetic, molecular, and clinical studies on the KCNB2 gene and its role in NDDs. Relevant literature was identified through database searches in PubMed, Embase, PsycINFO, Scopus, and Web of Science, focusing on studies that examine KCNB2's molecular mechanisms, pathogenic mutations, and clinical implications in NDDs. In addition to its role in excitability, KCNB2's impact on cognitive processes, such as memory and attention, is considered, highlighting the need for further research. Potential interventions, including pharmacological modulation and gene therapy, are also discussed. Future research should focus on characterizing KCNB2 variants, expanding genetic screening, and advancing targeted therapies to improve outcomes for individuals affected by KCNB2-related disorders.

Kv2.1 expression in giant reticular neurons of the postnatal mouse brain

Previous experiments charted the development of behavioral arousal in postnatal mice. From Postnatal Day 3 (P3) to Postnatal Day 6 (P6) mice (a) become significantly more active, "arousable"; and (b) in large reticular neurons, nucleus gigantocellularis (NGC), patch clamp recordings reveal a significantly increased ability to fire high frequency trains of action potentials as are associated with elevated cortical arousal. These action potential trains depend on delayed rectifiers such as Kv2.1. Here we report tracking the development of expression of a delayed rectifier, Kv2.1 in NGC neurons crucial for initiating CNS arousal. In tissue sections, light microscope immunohistochemistry revealed that expression of Kv2.1 in NGC neurons is greater at day P6 than at P3. Electron microscope immunohistochemistry revealed Kv2.1 labeling on the plasmalemmal surface of soma and dendrites, greater on P6 than P3. In brainstem reticular neuron cell culture, Kv2.1 immunocytochemistry increased monotonically from Days-In-Vitro 3-10, paralleling the ability of such neurons to fire action potential trains. The increase of Kv2.1 expression from P3 to P6, perhaps in conjunction with other delayed rectifier currents, could permit the ability to fire action potential trains in NGC neurons. Further work with genetically identified NGC neurons is indicated.