Magnitude and chemistry of LTP may depend on whether the induction paradigm is a theta burst (TBS) or a high frequency (HFS) stimulation pattern. TBS mimics endogenous neural activity but many studies also use HFS to induce LTP. We previously reported that a systematic comparison of TBS and HFS in hippocampal slices revealed that the magnitude of LTP was determined more by the total number of pulses rather than stimulation pattern (SFN Abstract, Vol. 27, 372.4, 2001). Two hundred and three hundred pulses produced significantly greater LTP in both paradigms when compared to the forty or one hundred pulse paradigms. We are currently investigating whether integrins are differentially involved in robust LTP resulting from the greater number of pulses. In CA1, TBS of 200 pulses and a 15 min bath application of GRGDSP peptide during induction significantly reduces field LTP at 250 μM (70.3% ± 5.0, n = 4) and 500 μM (49.6% ± 2.7, n = 3), when compared to ACSF controls (123.8% ± 18.8, n = 3; ANOVA, p <.05). HFS wi...