Synapse-Enriched m6A-Modified Malat1 Interacts with the Novel m6A Reader, DPYSL2, and Is Required for Fear-Extinction Memory.

The RNA modification N6-methyladenosine (m6A) regulates the interaction between RNA and various RNA binding proteins within the nucleus and other subcellular compartments and has recently been shown to be involved in experience-dependent plasticity, learning, and memory. Using m6A RNA-sequencing, we have discovered a distinct population of learning-related m6A- modified RNAs at the synapse, which includes the long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (Malat1). RNA immunoprecipitation and mass spectrometry revealed 12 new synapse-specific learning-induced m6A readers in the mPFC of male C57/BL6 mice, with m6A-modified Malat1 binding to a subset of these, including CYFIP2 and DPYSL2. In addition, a cell type- and synapse-specific, and state-dependent, reduction of m6A on Malat1 impairs fear-extinction memory; an effect that likely occurs through a disruption in the interaction between Malat1 and DPYSL2 and an associated decrease in dendritic spine formation. These findings highlight the critical role of m6A in regulating the functional state of RNA during the consolidation of fear-extinction memory, and expand the repertoire of experience-dependent m6A readers in the synaptic compartment.SIGNIFICANCE STATEMENT We have discovered that learning-induced m6A-modified RNA (including the long noncoding RNA, Malat1) accumulates in the synaptic compartment. We have identified several new m6A readers that are associated with fear extinction learning and demonstrate a causal relationship between m6A-modified Malat1 and the formation of fear-extinction memory. These findings highlight the role of m6A in regulating the functional state of an RNA during memory formation and expand the repertoire of experience-dependent m6A readers in the synaptic compartment.

Evaluation of Bone Wax Coated Bipolar Coagulation Forceps: Performance and Safety Assessment.

BACKGROUND: Improving the performance of bipolar coagulation forceps is crucial for safer and more accurate neurosurgery. In our department, we found that bone wax (BW) melted by thermal effect of bipolar electrocoagulation can achieve more efficient hemostasis and reduce the amount of BW in neurosurgical procedures associated with bleeding from emissary and diploic veins. Nevertheless, relevant studies are still lacking to verify our finding. OBJECTIVE: The study objectives were to evaluate the performance and safety in electrocoagulation: (1) compare the performance of BW coated bipolar coagulation forceps and the conventional anti-stick forceps in vivo, and (2) assess the safety of electrocoagulation with BW coated bipolar coagulation forceps in rat primary motor cortex. METHODS: Tissue adhesion was evaluated by comparing the wetting tension and the amount of protein adhered to the forceps tips after electrocoagulation. Thermal damage was assessed by analyzing the thermography and H&E staining of coagulated rat brain tissues. The hemostatic efficiency was reflected by the number of electrocoagulation until complete hemostasis and the condition of damaged common carotid arteries. The safety of BW coated forceps in electrocoagulation was assessed by evaluating the inflammation of coagulated rat primary motor cortex and the motor functions at the 7th day postoperatively. RESULTS: Bone wax coated forceps had a significantly higher contact angle and adhered less coagulum. Thermography was acquired at 3 s, 6 W units in rat primary motor cortex in vivo. The highest temperature recorded during BW coated tips application was significantly lower than the uncoated. In addition, there was a relatively smaller tissue injury area produced by the BW coated forceps. Additionally, BW coated forceps improved the hemostatic efficiency and caused fewer injuries on the damaged arteries (3 s, 10 W units). More importantly, electrocoagulation with BW coated forceps led to no significant motor function impairments and less glial and microglia responses. CONCLUSION: This study reveals that BW coated bipolar coagulation forceps can provide a convenient, cost-efficient, safer, and more efficient way for hemostasis. More research is needed to evaluate the electrocoagulation with BW in the long term and verify our finding in human beings.