title: Fear and safety engage competing patterns of theta-gamma coupling in the basolateral amygdala.
abstract: Theta oscillations synchronize the basolateral amygdala (BLA) with the hippocampus (HPC) and medial prefrontal cortex (mPFC) during fear expression. The role of gamma-frequency oscillations in the BLA is less well characterized. We examined gamma- and theta-frequency activity in recordings of neural activity from the BLA-HPC-mPFC circuit during fear conditioning, extinction, and exposure to an open field. In the BLA, slow (40-70 Hz) and fast (70-120 Hz) gamma oscillations were coupled to distinct phases of the theta cycle and reflected synchronous high-frequency unit activity. During periods of fear, BLA theta-fast gamma coupling was enhanced, while fast gamma power was suppressed. Periods of relative safety were associated with enhanced BLA fast gamma power, mPFC-to-BLA directionality, and strong coupling of BLA gamma to mPFC theta. These findings suggest that switches between states of fear and safety are mediated by changes in BLA gamma coupling to competitive theta frequency inputs.
authors.affiliation: Graduate Program in Neurobiology and Behavior, Columbia University, New York, NY 10032, USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Stujenske
authors.affiliation: Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Likhtik
authors.affiliation: Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA; Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, NY 10032, USA.
authors.forename: Mihir A
authors.initials: MA
authors.lastname: Topiwala
authors.affiliation: Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA; Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, NY 10032, USA. Electronic address: jg343@columbia.edu.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Gordon
mesh_terms: D000818:Animals; D066272:Basolateral Nuclear Complex / Q000502:physiology*; D003213:Conditioning, Psychological / Q000502:physiology; D005108:Extinction, Psychological / Q000502:physiology; D005239:Fear / Q000502:physiology*; D065818:Gamma Rhythm / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology*; D008297:Male; D051379:Mice; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000502:physiology; D017397:Prefrontal Cortex / Q000502:physiology*; D012449:Safety; D013826:Theta Rhythm / Q000502:physiology*