Ion channels are selective for particular ionic species, such as sodium (\(Na\)) or potassium (\(K\)), giving rise to currents \( <math/>I_{Na}<math> \) or \( I_K \ ,\) respectively.
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Ion channels are selective for particular ionic species, such as sodium (\(Na\)) or potassium (\(K\)), giving rise to currents \( I_{Na} \) or \( I_K \ ,\) respectively.