We then tested the genotypes for differences in transmitter release kinetics using paired pulse facilitation, a measure of the extent to which release triggered by a single stimulation pulse increases release by a slightly delayed second pulse. The Baf53b+/− het slices and BAF53bΔHDlow slices did not differ from wildtypes, but the BAF53ΔHDhigh group was enhanced (p<0.0001) (Fig 5G). However, whole cell recording indicated that the frequency and magnitude of miniature excitatory postsynaptic potentials in the BAF53ΔHDhigh slices were comparable to wildtype values (Fig 5H). In all, BAF53ΔHDhigh slices are characterized by depressed axon excitability and exaggerated transmitter mobilization while spontaneous release and associated post-synaptic receptor responses appear to be normal. The Baf53b+/− het slices and BAF53bΔHDlow cases were comparable to controls on all tests of baseline physiology.
