TrkB receptor antagonist ANA-12 impairs memory reconsolidation in novel object recognition task via regulation of hippocampal transcriptome

Memory reconsolidation is a re-stabilization phase in which memory is gradually changed from unstable to stable. This process is critical because unstable memories can be subject to modification or erasure if the reconsolidation phase is disrupted within a 6 h time window. TrkB signaling pathway plays a key role in regulating neurogenesis, neuronal differentiation, maturation and survival. Numerous studies have reported that the TrkB signaling pathway participates in memory acquisition, consolidation and storage, although its role in memory reconsolidation is not fully understood. ANA-12, as a type of TrkB receptor inhibitor, can regulate various pain behaviors and attenuate propofol-induced apoptosis by blocking the TrkB signaling pathway. In this study, we investigated the effect of ANA-12 on memory reconsolidation in a novel object recognition (NOR) task. The results showed that ANA-12 injection immediately after the reactivation phase of the NOR task inhibited memory reconsolidation, whereas ANA-12 injection 6 h after the reactivation phase had no effect on memory performance. ANA-12 injection 24 h after the sample phase, with no subsequent reactivation phase, had no effect on memory performance. Transcriptome analysis demonstrated that ANA-12 administration significantly upregulated 347 genes and downregulated 79 genes in the hippocampus, compared to vehicle-treated animals. Those differentially expressed genes are involved in a wide range of functional pathways, including neuroinflammation, neurotransmitter synthesis, metabolism and transport, and long-term potentiation, which are all linked to memory impairment. These findings indicate that ANA-12-induced impaired memory reconsolidation is associated with changes in multiple signaling pathways.