sentence: All samples were studied under the same conditions , which is imperative because electrophysiological properties are known to be sensitive to the concentration and type of salt ( NaCl vs. KCl ; Rostovtseva and Bezrukov , 1998 , 2015 ) , pH ( Bowen et al ., 1985 ; Colombini , 1989 ; Teijido et al ., 2014 ) , and membrane lipid composition ( Rostovtseva et al ., 2006 ; Mlayeh et al ., 2017 ; Queralt-Mart í n et al ., 2019 ) .