Objective:To observe the neuroanatomical properties of the projection pathway from the nucleus reuniens(Re)to the dorsal(dHC)and ventral(vHC)hippocampus.Methods:Adeno-associated virus SV40 was injected into the Re of C57BL/6 mice and the profile of downstream projection in the whole brain was examined and ranked.Retro-grade tracer Fluoro-Gold(FG)was injected into the whole hippocampus(wHC),dorsal hippocampus(dHC)or ven-tral hippocampus(vHC),and the distribution of the retrogradely labeled neurons and its relationship with calretinin(CR)in the Re were analyzed.Results:After injection of SV40 virus into the Re,we observed projection fibers or ter-minals in 18 areas across the brain.Among the areas,those to the hippocampus(HC)were mainly distributed in the dorsal and ventral lacunosum molecular layer,which ranked No.2 with regard to the projection intensity.Following injection of FG into the hippocampus,we observed that the retrogradely labeled neurons projecting to the wHC were densely distributed in the rostrocaudal segments of Re,with a more concentrated aggregation in the ventromedial part.FG+CR+double labeled neurons accounted for(47.47±0.07)％of FG labeled neurons,and for(67.13±0.10)％of CR+neurons in this case.The retrograde labeled neurons projecting to the dHC were sparse and mainly distributed in the dorsolateral part of Re.FG+CR+double labeled neurons accounted for(24.11±0.06)％of FG labeled neurons,and for(32.99±0.19)％of CR+neurons.The retrogradely labeled neurons projecting to the vHC were mainly distrib-uted in the ventralmedial part of Re.FG+CR+double labeled neurons accounted for(49.55±0.03)％of FG labeled neurons,and for(69.14±0.12)％of CR+neurons.Conclusion:Hippocampus is an essential target of the Re.The projections to the dHC and vHP differ in the location of projection neurons and the positive ratio with CR,which may re-flect the differential pathophysiological functions of the two pathways in vivo.

Objective:To observe the neuroanatomical properties of the projection pathway from the nucleus reuniens(Re)to the dorsal(dHC)and ventral(vHC)hippocampus.Methods:Adeno-associated virus SV40 was injected into the Re of C57BL/6 mice and the profile of downstream projection in the whole brain was examined and ranked.Retro-grade tracer Fluoro-Gold(FG)was injected into the whole hippocampus(wHC),dorsal hippocampus(dHC)or ven-tral hippocampus(vHC),and the distribution of the retrogradely labeled neurons and its relationship with calretinin(CR)in the Re were analyzed.Results:After injection of SV40 virus into the Re,we observed projection fibers or ter-minals in 18 areas across the brain.Among the areas,those to the hippocampus(HC)were mainly distributed in the dorsal and ventral lacunosum molecular layer,which ranked No.2 with regard to the projection intensity.Following injection of FG into the hippocampus,we observed that the retrogradely labeled neurons projecting to the wHC were densely distributed in the rostrocaudal segments of Re,with a more concentrated aggregation in the ventromedial part.FG+CR+double labeled neurons accounted for(47.47±0.07)％of FG labeled neurons,and for(67.13±0.10)％of CR+neurons in this case.The retrograde labeled neurons projecting to the dHC were sparse and mainly distributed in the dorsolateral part of Re.FG+CR+double labeled neurons accounted for(24.11±0.06)％of FG labeled neurons,and for(32.99±0.19)％of CR+neurons.The retrogradely labeled neurons projecting to the vHC were mainly distrib-uted in the ventralmedial part of Re.FG+CR+double labeled neurons accounted for(49.55±0.03)％of FG labeled neurons,and for(69.14±0.12)％of CR+neurons.Conclusion:Hippocampus is an essential target of the Re.The projections to the dHC and vHP differ in the location of projection neurons and the positive ratio with CR,which may re-flect the differential pathophysiological functions of the two pathways in vivo.

Objective : To explore the antibacterial activity of epigallocatechin-3-gallate (EGCG) on P. gingivalis and the inhibitory effects on matrix metalloproteinases (MMPs) production induced by P. gingivalis. Methods: The antimicrobial effect of EGCG against planktonic cultures and biofilms of P. gingivalis was evaluated using microplate dilution assays. The microstructural changes in biofilms were studied using scanning electron microscopy (SEM). The inhibitory effect of EGCG on arginine gingipain (Rgp) and lysine gingipain (Kgp) activity of P. gingivalis was evaluated using synthetic chromogenic peptides and fluorogenic substrates. Enzyme-linked immunosorbent assay (ELISA) and qRT-PCR analysis were used to assess MMP-1 and MMP-2 mRNA expression and secretion by human gingival fibroblasts (HGFs) stimulated with P. gingivalis in the presence or absence of EGCG, respectively. Results : The MIC and MBC of EGCG against P. gingivalis were 62.5 μg/mL and 500 μg/mL, respectively. EGCG can not only inhibit the biofilm formation of P. gingivalis but also has a scavenging effect on mature biofilms and can affect their viability. Additionally, 10 μg/mL and 50 μg/mL of EGCG inhibited the proteinase activities of Rgp and Kgp, respectively (P < 0.05). Finally, the mRNA expression and secretion of MMP-1 and MMP-2 by HGFs stimulated by P. gingivalis were significantly inhibited by 50 μg/mL of EGCG (P < 0.05). Conclusion EGCG exhibits antimicrobial effects against P. gingivalis and reduces the expression of MMPs by HGFs.