title: Hippocampal--prefrontal BDNF and memory for fear extinction.
abstract: Infusing brain-derived neurotrophic factor (BDNF) into the infralimbic (IL) prefrontal cortex is capable of inducing extinction. Little is known, however, about the circuits mediating BDNF effects on extinction or the extent to which extinction requires BDNF in IL. Using local pharmacological infusion of BDNF protein, or an antibody against BDNF, we found that BDNF in the IL, but not prelimbic (PL) prefrontal cortex, is both necessary and sufficient for fear extinction. Furthermore, we report that BDNF in IL can induce extinction of older fear memories (14 days) as well as recent fear memories (1 day). Using immunocytochemistry, we show that BDNF is increased in the ventral hippocampus (vHPC), but not IL or PL, following extinction training. Finally, we observed that infusing BDNF into the vHPC increased the firing rate of IL, but not PL neurons in fear conditioned rats. These findings indicate that an extinction-induced increase in BDNF within the vHPC enhances excitability in IL targets, thereby supporting extinction memories.
authors.affiliation: Departments of Psychiatry and Anatomy and Neurobiology, University of Puerto Rico, University of Puerto Rico School of Medicine, San Juan, Puerto Rico.
authors.forename: Luis E
authors.initials: LE
authors.lastname: Rosas-Vidal
authors.affiliation: Departments of Psychiatry and Anatomy and Neurobiology, University of Puerto Rico, University of Puerto Rico School of Medicine, San Juan, Puerto Rico.
authors.forename: Fabricio H
authors.initials: FH
authors.lastname: Do-Monte
authors.affiliation: Departments of Psychiatry and Anatomy and Neurobiology, University of Puerto Rico, University of Puerto Rico School of Medicine, San Juan, Puerto Rico.
authors.forename: Francisco
authors.initials: F
authors.lastname: Sotres-Bayon
authors.affiliation: Departments of Psychiatry and Anatomy and Neurobiology, University of Puerto Rico, University of Puerto Rico School of Medicine, San Juan, Puerto Rico.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Quirk
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D000906:Antibodies / Q000008:administration & dosage; D001307:Auditory Perception / Q000187:drug effects / Q000502:physiology; D019208:Brain-Derived Neurotrophic Factor / Q000037:antagonists & inhibitors / Q000378:metabolism*; D003213:Conditioning, Psychological / Q000187:drug effects / Q000502:physiology; D005108:Extinction, Psychological / Q000187:drug effects / Q000502:physiology*; D005239:Fear / Q000187:drug effects / Q000502:physiology*; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D011214:Practice, Psychological; D017397:Prefrontal Cortex / Q000187:drug effects / Q000502:physiology*; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000008:administration & dosage; D013997:Time Factors
chemical_list: D000906:Antibodies; D019208:Brain-Derived Neurotrophic Factor; D011994:Recombinant Proteins