Figure 8.

The presynaptic Fmr1 deletion phenotype can be rescued with an increase in release probability in presynaptic KO pairs. A, Left, Example average traces before and after 6 mm CaCl₂. Right, We obtained the relationship between CaCl₂ (Ca⁺²) concentration and increase of uEPSC1 amplitude. Data were fitted to a sigmoid curve. Dashed lines mark the [Ca⁺²] (6 mm) that corresponds to the average fractional increase of uEPSC1 amplitude found for WT/WT pairs over KO/WT pairs (0.62). B, Example average traces obtained from a KO/WT pair in the presence of 6 mm CaCl₂ before and after kynurenate (250 μm) application. C, Average blockade by kynurenate with 6 mm CaCl₂ closely matched the blockade for presynaptic WT pairs. D, More short-term depression in high Ca²⁺. KO/WT and WT/WT data in C and D are replotted from Figure 5. *p < 0.05. Calibrations: 20 pA, 2 ms.