Objective To observe the changes in the electrophysiological characteristics of primary hippocampal neurons after cryopreservation under different conditions.

Methods Primary hippocampal neurons cultured in vitro and hippocampal neurons recovered after being frozen in serum-free cryo-medium, DF12+10% DMSO cryo-medium, DF12+10% DMSO+trehalose cryo-medium on the day of culture. After culturing for 14 to 16 days, the action potential, miniature inhibitory postsynaptic current (mIPSC), and miniature excitatory postsynaptic current (mEPSC) of each group were recorded by patch-clamp.

Results Electrophysiological characteristics of hippocampal neurons cryopreserved in cryopreservation fluid containing trehalose were similar to those of unfrozen primary culture hippocampal neurons. However, neurons cryopreserved in serum-free cryo-medium had obvious Burst-like discharge after resuscitation (P < 0.05), the amplitude of mIPSC was weakened (P < 0.001); similarly, neurons cryopreserved in DF12+10% DMSO cryo-medium also had obvious Burst-like discharge (P < 0.05), the amplitude of mIPSC was weakened (P < 0.001), and the frequency of mIPSC decreased (P < 0.01).

Conclusions Trehalose has a protective effect on the frozen hippocampal neurons after resuscitation.