Figure 2.

The blockade of N-type Ca²⁺ channels by ω-conotoxin GVIA reverses the inhibitory effect of SynII deletion on the asynchronous GABAergic release component. A, The blockade of N-type Ca²⁺ channels by ω-conotoxin GVIA (250 nm) significantly reduces the basal inhibitory transmission in both genotypes. B, Representative current traces elicited by 50 Hz tetani illustrate the reduced postsynaptic signal in both lines upon ω-conotoxin GVIA application. Notably, the effect of the treatment on the after tetanus current is stronger in WT slices. Stimulus artifacts are removed for clarity. C, The ω-conotoxin GVIA treatment significantly (p < 0.005) reduces the frequency of asynchronous peaks at WT but not at SynII(−) slices. D, The effect of ω-conotoxin GVIA on the charge transfer during the tetanus is similar at WT and SynII(−) slices. E, The effect of ω-conotoxin GVIA on the charge transfer after the tetanus is significantly stronger at WT slices (p < 0.01). F, The ω-conotoxin GVIA treatment reduces the After/During charge ratio at WT (p < 0.005) but not at SynII(−) slices. Data collected from 13 slices for each genotype. *p < 0.05, **p < 0.01, ***p < 0.005.