Esketamine enhances memory reconsolidation in the novel object recognition task.

Esketamine, the right-handed optical isomer of racemic ketamine, is a rapidly acting antidepressant approved by the FDA for treatment-resistant depression in 2019. However, few studies have investigated esketamine's role in learning and memory, particularly in the context of memory reconsolidation. Herein, we evaluated esketamine's role in memory reconsolidation in 7-week-old male Institute of Cancer Research mice subjected to the novel object recognition (NOR) memory task. The NOR reconsolidation procedure comprised three phases: sampling, reactivation, and testing. Esketamine-enhanced NOR memory performance when injected into mice 0 h after reactivation rather than following a 6 h delay. Conversely, administering esketamine 24 h after sampling without reactivation did not enhance NOR memory performance. Notably, esketamine exhibited no discernible effects on nonspecific responses, such as locomotor activity and exploratory behavior. Furthermore, the α-amino-3­hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type receptor antagonist NBQX effectively blocked the esketamine-induced enhancement of memory reconsolidation. In conclusion, esketamine treatment markedly improves memory reconsolidation in NOR tasks, and this effect is linked to AMPA receptor activity.

Helicobacter pylori induces NOD1/NF-κB activation and IFN-βand IP-10 production in gastrics of mice / 中国免疫学杂志

Objective:To construct the Helicobacter pylori infected C57BL/6 mice model to observe the activation of NOD1/NF-κB signaling pathways in the gastric tissues,and study its roles in inflammatory response during Hp infection.Methods:6-8 week-old C57BL/6 mice were randomly divided into two groups,the Hp infection group and the control group,and mice were given by gavage every 48 h for five times with Hp or PBS,respectively.All the animals were sacrificed at different time point and the gastric tissue were stained with hematoxylin-eosin( HE);The mRNA expression of NOD1 and RIP2 in gastric tissues were examined by RT-PCR;Levels of IFN-βand IP-10 in mice serum were assessed by ELISA;Nuclear translocation of p65 in gastric tissue was detected by Western blot.Results:Hp infection elicits an inflammatory cell response,glands in gastric tissue were reduced or atrophic,as compared with that in the control group.The levels of IP-10 and IFN-βincreased in the model group, and peaked at 16 weeks after Hp infection.Hp infection increased the mRNA expression of NOD1 and the p65 content in nuclear between 24-120 h(P<0.05),and the highest level at 48 h,subsequently the expression levels were began to decrease.The mRNA expression level of RIP2 was up-regulated after Hp was administrated, peaked at 48 h and declined after 72 h.However, the expression levels would rise again at 120 h.Conclusion: Hp infection can activate the NOD1/NF-κB signaling pathways and induce the production of IFN-βand IP-10 in gastrics of mice.