Deoxyschisandrin modulates synchronized Ca2+ oscillations and spontaneous synaptic transmission of cultured hippocampal neurons.
OBJECTIVE
Deoxyschisandrin is one of the most effective composites of Schisandra chinensis, a famous Chinese medicine widely used as an antistress, anti-aging, and neurological performance-improving herb. In this study, we examined its specific mechanisms of action on cultured hippocampal neurons.


METHODS
Hippocampal neurons, primarily cultured for 9-11 d in vitro, were used for this study. DS were dissolved in DMSO and applied to calcium imaging and whole-cell patch clamp.


RESULTS
The application of 3 mg/L DS decreased the frequency of spontaneous and synchronous oscillations of intracellular Ca2+ to 72%+/-2% (mean+/-SEM), and the spontaneous inhibitory postsynaptic currents to 60%+/-3% (mean+/-SEM). The inhibitory concentration 50% (IC50) for the effect of DS on calcium oscillations was 3.8 mg/L. DS also depressed the high voltage-gated Ca2+ channel and the voltage-gated Na+ channel currents at the same time point. It had no effect, however, on voltage-gated K+ and spontaneous excitatory postsynaptic currents.


CONCLUSIONS
DS inhibited the spontaneous and synchronous oscillations of intracellular Ca2+ through the depression of influx of extracellular calcium and the initiation of action potential. By repressing the spontaneous neurotransmitter release, DS modulated the neuronal network activities.
Fu
Min
M
Medical College of Tsinghua University, Beijing 100084, China.
Sun
Zhao-hui
ZH
Zong
Min
M
He
Xiang-ping
XP
Zuo
Huan-cong
HC
Xie
Zuo-ping
ZP
D000818:Animals; D020013:Calcium Signaling / Q000187:drug effects*; D002478:Cells, Cultured; D034242:Cyclooctanes / Q000494:pharmacology*; D004594:Electrophysiology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects*; D017705:Lignans / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects*; D011083:Polycyclic Compounds / Q000494:pharmacology*; D051381:Rats; D032141:Schisandra / Q000737:chemistry; D026941:Sodium Channel Blockers / Q000494:pharmacology; D015222:Sodium Channels / Q000187:drug effects; D009435:Synaptic Transmission / Q000187:drug effects*
D034242:Cyclooctanes; D017705:Lignans; D011083:Polycyclic Compounds; D026941:Sodium Channel Blockers; D015222:Sodium Channels; C034734:schizandrin A