Rhythmic electrical impulses that drive beating of the heart and sleep waves in the brain are controlled by natural pacemakers called ion channels. Pacemaker channels act as electrical switches, and they switch on faster when they bind natural chemical messenger molecules called cyclic nucleotides (CNs). This is thought to involve temporary structural changes in the region of the channel molecule that interacts with the CNs. By modifying the structure of the CN-binding region in the channel and observing how this affects switching, Dr. Edgar Young is studying what structural features of the channels help or hinder this process. Gaining a better understanding of the structural changes that allow switching may lead to the development of new drugs to control pacemaker acceleration, which could alleviate problems such as accelerated heartbeats or epileptic seizures.