You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["HealthCareActivity", "InjuryOrPoisoning", "BodySubstance", "IntellectualProduct", "AnatomicalStructure", "SpatialConcept", "Chemical", "Bacterium", "MedicalDevice", "Organization", "BiomedicalOccupationOrDiscipline", "Finding", "BiologicFunction", "Virus", "ResearchActivity", "ClinicalAttribute", "PopulationGroup", "Eukaryote", "BodySystem", "Food", "ProfessionalOrOccupationalGroup"].

Please return the output as a JSON object of the format: {"Virus": ["HIV", ...], "Bacterium": ["MRSA", ...], "AnatomicalStructure": ["Lung", ...], "BodySystem": ["CNS", ...], "BodySubstance": ["Serum", ...], "Finding": ["Headache", ...], "InjuryOrPoisoning": ["Fracture", ...], "BiologicFunction": ["Death", ...], "HealthCareActivity": ["Biopsy", ...], "ResearchActivity": ["Clinical trial", ...], "MedicalDevice": ["Lenses", ...], "SpatialConcept": ["Camps", ...], "BiomedicalOccupationOrDiscipline": ["Forensic medicine", ...], "Organization": ["WHO", ...], "ProfessionalOrOccupationalGroup": ["Provider", ...], "PopulationGroup": ["Swimmers", ...], "Chemical": ["Gold", ...], "Food": ["Rice", ...], "IntellectualProduct": ["RPAM", ...], "ClinicalAttribute": ["Biomarker", ...], "Eukaryote": ["Dogs", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Reassembly of Excitable Domains after CNS Axon Regeneration Action potential initiation and propagation in myelinated axons require ion channel clustering at axon initial segments (AIS) and nodes of Ranvier. Disruption of these domains after injury impairs nervous system function. Traditionally, injured CNS axons are considered refractory to regeneration, but some recent approaches challenge this view by showing robust long-distance regeneration. However, whether these approaches allow remyelination and promote the reestablishment of AIS and nodes of Ranvier is unknown. Using mouse optic nerve crush as a model for CNS traumatic injury, we performed a detailed analysis of AIS and node disruption after nerve crush. We found significant disruption of AIS and loss of nodes within days of the crush, and complete loss of nodes 1 week after injury. Genetic deletion of the tumor suppressor phosphatase and tensin homolog (Pten) in retinal ganglion cells (RGCs), coupled with stimulation of RGCs by inflammation and cAMP, dramatically enhanced regeneration. With this treatmen t, we found significant reestablishment of RGC AIS, remyelination, and even reassembly of nodes in regions proximal, within, and distal to the crush site. Remyelination began near the retina, progressed distally, and was confirmed by electron microscopy. Although axons grew rapidly, remyelination and nodal ion channel clustering was much slower. Finally, genetic deletion of ankyrinG from RGCs to block AIS reassembly did not affect axon regeneration, indicating that preservation of neuronal polarity is not required for axon regeneration. Together, our results demonstrate, for the first time, that regenerating CNS axons can be remyelinated and reassemble new AIS and nodes of Ranvier. We show, for the first time, that regenerated CNS axons have the capacity to both remyelinate and reassemble the axon initial segments and nodes of Ranvier necessary for rapid and efficient action potential propagation.
{"AnatomicalStructure": ["tumor suppressor phosphatase and tensin homolog", "(AIS", "RGCs", "RGC", "axons", "Pten", "retinal ganglion cells", "optic nerve", "AIS", "axon initial segments"], "Bacterium": [], "BiologicFunction": ["regenerating", "inflammation", "Action potential initiation", "refractory", "ion channel clustering", "genetic deletion", "nodal ion channel clustering", "Genetic deletion", "remyelinated", "action potential propagation", "axon regeneration", "remyelinate", "nervous system function", "Axon Regeneration", "regeneration", "Remyelination", "propagation", "regenerated", "remyelination", "grew", "stimulation", "model"], "BiomedicalOccupationOrDiscipline": [], "BodySubstance": [], "BodySystem": ["CNS"], "Chemical": ["ankyrinG", "cAMP"], "ClinicalAttribute": [], "Eukaryote": ["mouse"], "Finding": ["not required"], "Food": [], "HealthCareActivity": ["electron microscopy"], "InjuryOrPoisoning": ["injury", "traumatic injury", "crush", "nerve crush"], "IntellectualProduct": [], "MedicalDevice": [], "Organization": [], "PopulationGroup": [], "ProfessionalOrOccupationalGroup": [], "ResearchActivity": ["analysis", "treatmen"], "SpatialConcept": ["distal", "near the retina", "neuronal polarity", "regions proximal", "within", "nodes", "distally", "site", "node", "nodes of Ranvier"], "Virus": []}