Effect of ganglioside on synaptic plasticity of hippocampus in lead-exposed rats in vivo.

Synaptic plasticity, including long-term potentiation (LTP), long-term depression (LTD) and depotentiation (DP), is important for learning and memory. Previous studies proved that chronic lead exposure especially during early post-natal development induced impairment on synapse plasticity. The purpose of this study is to evaluate the effect of ganglioside on the lead-induced impairments of LTP and DP in rat dentate gyrus in vivo. The experiments were carried out in three groups of rats (control, lead-exposed, ganglioside-treated lead-exposed, respectively). The input-output (I/O) function, pair pulses reaction, excitatory post-synaptic potential (EPSP) and population spike (PS) amplitude were measured in the dentate gyrus (DG) of adult rats (70-90 days) in response to stimulation applied to the lateral perforant path. The results show that (1) chronic lead exposure impaired LTP/DP measured on both EPSP slope and PS amplitude in DG area of the hippocampus. (2) The amplitudes of LTP/DP of lead-exposed group were significantly increased by supplying ganglioside. These results suggest intraperitoneally injection with ganglioside could reverse the lead-induced impairments of synaptic plasticity in rats and might be effective in attenuating the cognitive deficits induced by lead.