Fig. A3.

Quantification of Mg²⁺ and Ca²⁺ recording solution concentrations among articles in quality control subset. A: 2-dimensional histogram of Mg²⁺ and Ca²⁺ recording solution concentrations, reported in mM. The most commonly reported concentration pair is 1 mM Mg²⁺ and 2 mM Ca²⁺. B: same as A, but reported as ratio of Mg²⁺ and Ca²⁺ concentration; n = 27 articles quantified; 2 articles not shown since in vivo recording conditions were used and no external recording solution was reported.