Fig 6.

The postsynaptic depolarization as a result of presynaptic burst activity is increased and prolonged during repetitive bursts. (A) Short-term depression of PSP amplitudes between spiny projection neurons. Data taken from first two spikes in bursts below facilitation threshold (*, P < 0.05 compared to last two groups, all culture). (B) Summary data showing a significantly prolonged decay in postsynaptic depolarization after burst termination at frequencies above 16 Hz (1-s current pulse duration; *, P < 0.05 compared to first group, n = 6 neurons, all culture). (C) Example of prolonged postsynaptic decay after high frequency bursts of 1-s duration (same neuron, open arrow; V_Rest pre = −80 mV and V_Rest post = −72 mV). (D) Short-term facilitation of PSP amplitudes by preceding bursts. Overplot of PSP response to the first spike in a burst as a function of number of spikes (right) in the preceding burst (1.5-s interburst interval, same neuron as in Fig. 5B). (E) If the preceding burst contains more than eight spikes per 500 ms pulse duration (>16 Hz), a single PSP after 1 s is facilitated by up to 100% (*, P < 0.05 compared to first group, n = 9 neurons, all culture). Numbers in graphs indicate number of cases for each class.