{'fraction_non_alphanumeric': 0.03290246768507638, 'fraction_numerical': 0.01880141010575793, 'mean_word_length': 4.795918367346939, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Sodium channel permeation in squid axons. II: Non‐independence and current‐voltage relations.

1. The concentration and voltage dependence of current through the Na channels of squid giant axons was studied. The permeant cations Na, K and ammonium were used. 2. The Na channel current at a fixed voltage saturates as the internal permeant ion concentration is increased. The half‐saturation activities at 50 mV were found to be 623, 268, 161 mM for Na, NH4, and K, respectively. These Km values for Na and K appear to be voltage‐dependent. 3. Instantaneous current‐voltage relations were determined with two different internal Na concentrations and with Na outside and K inside. 4. A three‐barrier, two‐site ion permeation model previously used in describing Na channel reversal potentials is shown here to account for the Na channel currents as well.