An integrin binding peptide reduces rat CA1 hippocampal long-term potentiation during the first few minutes following theta burst stimulation.

The integrin binding peptide GRGDSP was tested on Schaffer to CA1 (Sch-CA1) long-term potentiation (LTP) in the rat hippocampal slice. Experiments in which GRGDSP was bath applied for 50 min, beginning 10 min before theta burst stimulation (TBS), reduced LTP of the field excitatory post synaptic potential in a concentration dependent manner, with 250 microM producing a significant decrease. However, LTP was not affected when 250 microM GRGDSP was applied 30 min post-TBS, nor when applied as soon as 5 min post-TBS. When 250 microM GRGDSP was applied for only 10 min pre- to 5 min post-TBS, this brief application was sufficient in reducing LTP similar to the extended 50 min application. We conclude that RGD-binding integrins involved in LTP are only momentarily responsive to peptide-mediated antagonism in the first few minutes following TBS.