Fig. 3.

Hippocampal LTP. In the following experiments, hippocampal slices obtained from PKCβ-deficient mice (○) or wild-type mice (●) were given an LTP-inducing stimulus (arrows) delivered after stable baseline responses were recorded for 20 min. Each set of tetani consisted of two trains of 100 Hz stimulation for 1 sec, separated by 20 sec. A, Mutant hippocampal slices showed normal LTP compared with wild types after a modest LTP-inducing protocol consisting of a single set of tetani while maintaining slices at 25°C. B, The extent of depotentiation in PKCβ-deficient mice was equal to that of wild types determined from low-frequency 5 Hz stimulation (5 min) after a single set of tetani at 25°C. C, No differences in PKCβ mutant LTP were observed in experiments using a more robust LTP-inducing protocol consisting of three sets of 100 Hz tetani delivered 10 min apart while maintaining slices at an elevated temperature of 32°C.