The 5-HT 7 receptor antagonist SB 269970 counteracts restraint stress-induced attenuation of long-term potentiation in rat frontal cortex

The effects of restraint lasting for 10 min,repeated twice daily for 3 days,were studied ex vivo in rat frontal cortex slices prepared 24 h after the last stress session. in slices originating from stressed animals,the amplitude of extracellular field potentials recorded in cortical layer ii/iii was increased. stress also resulted in a reduced magnitude of long-term potentiation (ltp) of field potentials. in a separate experimental group,rats were infjected to restraint lasting for 10 min,twice daily for 3 days but,additionally,animals received injections of 5-ht 7 receptor antagonist sb 269970 (1.25 mg/kg) before each restraint stress session. in this group,the amplitude of field potentials and the magnitude of ltp were not different from the control,indicating that stress-induced modifications of basal glutamatergic transmission and synaptic plasticity were prevented by the 5-ht 7 receptor antagonist.