The effects of Tiao-Xin-Fang(TXF) on long-term potentiation (LTP) in rat hippocampal slices pretreated with β-amyloid or corticosterone were investigated by extracellular microelectrode recording technique.The results showed that the successful rate of evoking LTP was about 60% under normal condition.The PS amplitude was significantly increased and PS latent period was decreased.Pre-incubation of hippocampal slices with β-amyloid(0.2μM) or corticosterone(2μM) had little effect on either the sharp or amplitude of PS

indicating that they didn't influence the basal synaptic transmission.However

after tetanus the LTP induction rate and PS amplitude were both obviously decreased compared with the control

suggesting either of them inhibited LTP generation.In vitro application of TXF(7.45mg/ml) significantly antagonized their inhibitory effects on LTP induction.These results suggested that TXF antagonized the inhibitory effects of β-amyloid and corticosterone on LTP in rat hippocampal slices and that may be one of the mechanisms of TXF in improving the impaired learning and memory function of Alzheimer's disease patients.