Our previous pharmacological studies demonstrated that LW possesses effect of ameliorating the decline of the learning and memory in senescence accelerated mouse/prone 8 (SAMP8), but the mechanism has not been well established. LW-containing serum (LWCS) is used in the current study to elucidate the possible mechanisms.
6-month-old SAMP8 was used in this study to investigate the effect of LWCS on the induction of long-term potentiation (LTP). Primary cultured hippocampal neurons were used in this study to investigate the effects of LWCS on [Ca<sup>2+sup>]<sub>isub>, I<sub>Casub> and N-Methyl-d-aspartate (NMDA)-evoked currents. [Ca<sup>2+sup>]<sub>isub> was imaged using Fluo-3 and whole-cell patch recordings were applied to study the I<sub>Casub> and NMDA-evoked currents.
We find that LWCS facilitates the induction of LTP in hippocampal slices of 6-month-old SAMP8. In primary cultured hippocampal neurons, LWCS increases intracellular [Ca<sup>2+sup>]<sub>isub>, the I<sub>Casub> is suppressed by LWCS, and NMDA-evoked currents are promoted.
These results indicate that LW improves the synaptic plasticity by inhibiting voltage-dependent calciumchannels (VDCCs) and promoting the function of NMDA receptors. This improvement might be one of the mechanisms contributing to cognitive improvement effect of LW.