Figure 4

The RyRs blockade impacts only the maintenance of Ca²⁺ signal during L-Lactate-induced potentiation. (A₁,B₁) Averaged Ca²⁺ traces recorded from 65 neurons (A₁) and 49 neurons (B₁) following 2 successive applications of glutamate/glycine (2 min; dots) in control and in presence of L-Lactate (10 mM), the neurons in B₁ coming from a culture pre-treated with ryanodine (100 μM). (A₂,B₂) The scaling of evoked Ca²⁺ responses obtained in (A₁ and B₁) shows that the L-Lactate-induced potentiation also corresponds to an increase of the decay time (in comparison with the scaled Ca²⁺ response obtained in control, A₂), with ryanodine blocking this effect on the Ca²⁺ response kinetics (B₂). (C₁,C₂) Bar charts summarizing the effect of L-Lactate on the Ca²⁺ signal triggered by co-application of glutamate/glycine on untreated cultures (n_cult = 11; n_cells = 468; C₁) or cultures pre-treated with ryanodine (n_cult = 7; n_cells = 331; C₂). Note that, when cultures are pre-treated with ryanodine, the potentiating effect of L-Lactate significantly persists only for the amplitude of the Ca²⁺ signal. Results are presented as means ± SEM (*p < 0.05; ***p < 0.005; paired t-test).