EN
Wistar rats were subjected to restraint lasting 10 min and repeated twice daily for 3, 7 and 14 days. Brain slices were prepared 24 h after the last restraint session and studied ex vivo. In slices of the frontal cortex field potentials (FPs) were evoked by electrical stimulation of underlying sites in the cortical layer V and recorded in layer II/III. In the hippocampal slices field excitatory postsynaptic potentials were evoked by stimulation of Schaffer collaterals and recorded in the stratum radiatum of the CA1 area. In cortical preparations significant differences between experimental and control groups were evident already after 3 days of restraint stress and consisted of an increase in the maximum FP amplitude (3.0 mV vs. 2.2 mV, respectively) as well as a reduced long-term potentiation (LTP; 112 % vs. 139 % of baseline, respectively). While in the frontal cortex there were no differences after 7 or 14 days of restraint, in the hippocampus a significant effect of restraint stress, namely a reduction of LTP (from 146 % to 120 % of baseline) was observed only after 14 days of restraint. These results indicate that repeated restraint stress differentially modulates synaptic transmission and plasticity in the two brain areas studied. Support: “DeMeTer” and statutory funds from the Institute of Pharmacology.