antiinterleukin1 antibody prevents the occurrence of repeated restraint stressinduced alterations in synaptic transmission and longterm potentiation in the rat frontal cortex background the mechanisms of the influence of prolonged stress on glutamatergic transmission and synaptic plasticity in the cerebral cortex remain poorly understood the purpose of this study was to determine an involvement of interleukin1 il1 in the effects of repeated restraint stress on excitatory synaptic transmission and longterm potentiation ltp in the rat frontal cortexmethods the effects of restraint stress lasting for 10 min repeated twice daily for 3 consecutive days were studied ex vivo in the rat frontal cortex slices prepared 24h after the last stress session rats received intraperitoneal injections of interleukin1 antibody in a separate experimental group rats received injections of il1 field potentials were recorded in the cortical layer iiiiiresults in slices originating from stressed animals the amplitude of field potentials was increased consistent with the previous studies restraint stress resulted in a reduced magnitude of ltp similar effects were evident after administration of il1 stressinduced modifications of the glutamatergic transmission and synaptic plasticity were prevented by interleukin1 antibody which was administered 15 min before each restraint sessionconclusions these data point to an involvement of peripherally produced il1 in mediating the influence of repeated restraint stress on the functions of the frontal cortex