Pertussis toxin suppresses long-term potentiation of hippocampal mossy fiber synapses.

The long-term potentiation (LTP) was studied using rat hippocampal slices in vitro. LTP in mossy fiber-CA3 pyramidal cell synapses was markedly suppressed in slices prepared from rats which had previously received intraventricular injection of pertussis toxin (PTX), compared with the bovine serum albumin-injected controls, suggesting the involvement of G-proteins in the mechanism of LTP in mossy fiber synapses. In contrast, LTP in Schaffer/commissural-CA1 pyramidal synapses was not affected by PTX pretreatment.