Fig. 3

Mast cell mediator cocktail (MCM) directly elicits [Ca²⁺]_i transients in hippocampal neurons. a [Ca²⁺]_i signals evoked by single pressure ejection pulses of 5 s of pure extract of MCM (solid trace) and 70 mM [K⁺] Locke solution (dashed trace). The resulting calcium responses obtained by MCM was compared with calcium responses elicited by depolarization. b Representative [Ca²⁺]_i signal evoked by a single pressure ejection pulse of 5 s of MCM at 1:1 dilution. In order to estimate the minimal number of MCs necessary to obtain enough amount of mediators to induce a calcium transient in neurons, different dilutions from pure MCM were made. c Representative [Ca²⁺]_i signal evoked by a single pressure ejection pulse of 5 s of MCM at 1:3 dilution. d [Ca²⁺]_i signal evoked by a single pressure ejection pulse of 5 s of MCM a 1:10 dilution. e Mean [Ca²⁺]_i peak obtained in neuronal responses evoked by 70 mM [K⁺] and MCM at 1:0 (pure), 1:1, 1:3, and 1:10 dilutions. f Mean area under curve obtained from [Ca²⁺]_i transients in neurons evoked by 70 mM [K⁺] and MCM at 1:0 (pure), 1:1, 1:3, and 1:10 dilutions. The latter was the lowest effective dilution capable of stimulating neurons. *p < 0.05, ***p < 0.001