{'fraction_non_alphanumeric': 0.05327868852459016, 'fraction_numerical': 0.030327868852459017, 'mean_word_length': 4.898550724637682, '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}}
Higher than Equilibrium Intracellular Cl‐ Concentration in Dorsal Root Ganglion Neurons of NKCC1 Knockout Mice

It is well established that intracellular Cl‐ concentration [Cl‐]i in dorsal root ganglion (DRG) neurons is maintained above electrochemical equilibrium via Na+K+2Cl‐ cotransporter NKCC1. To determine if NKCC1 is the only mechanism of active accumulation of Cl‐ in primary sensory neurons, we measured [Cl‐]i in freshly dissociated DRG neurons of NKCC1 knockout (KO) and wild‐type (WT) mice (p5 to p21), using MQAE and fluorescence imaging microscopy. The basal [Cl‐]i in 54 WT neurons was 35.7 ± 18 (SD) mM i.e. two to three times higher than expected for a passive distribution. The corresponding Cl‐ equilibrium potential (ECl) was ‐36.6 ± 13 mV. The basal [Cl‐]i in NKCC1 KO neurons (n=121) was 31.6 ± 17.4 mM, and the corresponding ECl was ‐40.4 ± 14.5 mV. The differences between means of WT and KO [Cl‐]i and ECl were not statistically significant. These results suggest that NKCC1 is not the only active transport mechanism maintaining intracellular Cl‐ above equilibrium in DRG neurons. Whether these additional transport mechanisms are compensatory or exist in WT neurons, remains to be determined.