An in vitro study of the effect of lipoxygenase and cyclo-oxygenase inhibitors of arachidonic acid on the induction and maintenance of long-term potentiation in the hippocampus.

The effects on tetanus-induced long-term potentiation (LTP) of the lipoxygenase and phospholipase A2 inhibitor nordihydroguaiaretic acid (NDGA), and of the cyclo-oxygenase inhibitor indomethacin have been investigated in area CA1 of the hippocampal slice. In the presence of NDGA, tetanic stimulation of Schaffer collaterals produces an attenuated potentiation of the population excitatory postsynaptic potential (EPSP) lasting for less than 1 h. Indomethacin does not impair LTP of the EPSP. Neither drug significantly reduces LTP of the population spike. NDGA, but not indomethacin, reversibly reduces pre-established LTP. The results suggest a role for arachidonic acid or its lipoxygenase metabolites, but not its cyclo-oxygenase metabolites, in the induction and expression of tetanus-induced LTP in area CA1.