Ion channels are gatekeepers, regulating neuronal excitability and neurotransmitter release. Genetic mutations to Kv1.1, a subunit of the potassium ion channel, are associated with episodic ataxia type 1 (EA1), with cerebellar dysfunction and uncontrolled motor activity that sometimes includes epileptic seizures. Joost Heeroma and colleagues show that Kv1.1 suppresses excitability in neurons and prevents neurotransmitter release. Mutations to Kv1.1 associated with episodic ataxia increase neurotransmitter release. Kv1.1 mutations variably affect neuronal excitability, providing some insight into the range of phenotypes associated with EA1 in patients.
