HCN Channels: Biophysics and Functional Relevance
Hyperpolarization-activated Cyclic Nucleotide-gated channels (HCN) are ion channels largely expressed in excitable tissues. In the heart, they generate the spontaneous electrical oscillations of pacemaker cells, while in neurons they are involved in the control of cell excitability.
Cardiac Pacemaking: Properties and Functions of the Pacemaker “Funny” (If) Current
The heart of a healthy person beats on average 2.5 billion times in a lifetime at a frequency ranging from ∼40 bpm (beats per minute, sleep) to ∼220 bpm (maximal exercise).
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