Effect of active fraction of Tiaoxin Recipe on long-term potentiation inhibited by corticosterone in area CA1 of rat hippocampal slices / 中草药

ABSTRACT

Objective To investigate the effect of active fraction A (TXR-A) extracted from Tiaoxin Recipe (TXR) on inhibition of corticosterone on long-term potentiation (LTP) induced by high frequency stimulation (HFS) in rat hippocampal slices. Methods The slices were divided into control, corticosterone, corticosterone+TXR, and corticosterone+different concentration of TXR-A groups, then were incubated with artificial cerebrospinal fluid (ACSF) added by drugs for 1 h before recording and were perfused with the same ACSF during recording. Population spike (PS) was recorded from stratum pyramidale of area CA1 using extracellular recording following stimulation of Schaffer collaterals in rat hippocampal slices. Then a 100 Hz, 100 pulses HFS was used to induce LTP. Results PS amplitude was decreased significantly vs that in the control group, when the slices were pre-incubated in ACSF added by corticosterone (2 ?mol/L) over 1.5 h, meaning that LTP was inhibited by corticosterone. However, PS amplitude of the slices pre-incubated in ACSF added by corticosterone (2 ?mol/L) and high concentration TXR-A was increased significantly vs that of corticosterone pre-treating slices, meaning that high concentration TXR-A enhanced LTP inhibited by corticosterone. Furthermore, increased LTP amplitude in high concentration TXR-A was much more than that in TXR. Conclusion TXR-A is one of main TXR active ingredients which facilitate LTP inhibited by corticosterone in area CA1 of rat hippocampal slices. The antagonist (effect) on corticosterone inhibition on LTP is one of the mechanisms to benefit the intelligence.