{'fraction_non_alphanumeric': 0.04337050805452292, 'fraction_numerical': 0.024783147459727387, 'mean_word_length': 4.2435064935064934, '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}}
A regenerative calcium response in Paramecium.

1. Standard intracellular current-passing and recording techniques were used to investigate the electrical properties of the membrane of Paramecium caudatum . 2. The surface membrane produces regenerative depolarizations graded in amplitude and rate of rise with the intensity of applied outward current pulses. In a solution of 1 mM-CaCl 2 , 1 mM-KCl and 1 mM Tris-HCl at pH 7.2 and 18 °C the overshoot reaches a maximum amplitude of + 5 to + 15 mV, and shows a maximum rate of rise of about 7 V/sec. 3. The overshoot is insensitive to Li, + , Na + , Cl - , TTX and procaine, but increases slightly (up to 10 mV/10-fold rise in ion concentration) in the presence of K + , Rb + , Cs + , NH + 4 , Mg 2+ and tetraethylammonium. 4. The overshoot increases 22-25 mV for each 10-fold increase in external [Ca]. Ba 2+ and Sr 2+ convert the graded response to one that is all-or-none. 5. Repolarization following the peak of the response is more rapid than expected from the time constant of the resting membrane, suggesting delayed rectification. 6. A conditioning depolarization causes inactivation of the regenerative response, and hyperpolarization depresses the response to a given stimulus current. Refractoriness persists for up to 200 msec after each response. 7. The regenerative response of the membrane is consistent with a transient increase in conductance to Ca 2+ (Ba 2+ , Sr 2+ ) with a consequent inwardly directed calcium current. This agrees with recent evidence that ciliary reversal (which accompanies depolarization) is produced by an influx of Ca 2+ .