title: Safety encoding in the basal amygdala.
abstract: Learning to fear and avoid life-threatening stimuli are critical survival skills but are maladaptive when they persist in the absence of a direct threat. Thus, it is important to detect when a situation is safe and to increase behaviors leading to naturally rewarding actions, such as feeding and mating. It is unclear how the brain distinguishes between dangerous and safe situations. Here, we present a novel protocol designed to investigate the processing of cues that predict danger, safety, or reward (sucrose). In vivo single unit recordings were obtained in the basal amygdala of freely behaving rats undergoing simultaneous reward, fear, and safety conditioning. We observed a population of neurons that did not respond to a Fear Cue but did change their firing rate during the combined presentation of a fear cue simultaneous with a second, safety, cue; this combination of Fear + Safety Cues signified "no shock." This neural population consisted of two subpopulations: neurons that responded to the Fear + Safety Cue but not the Fear or Reward Cue ("safety" neurons), and neurons that responded to the Fear + Safety and Reward Cue but not the Fear Cue ("safety + reward" neurons). These data demonstrate the presence of neurons in the basal amygdala that are selectively responsive to Safety Cues. Furthermore, these data suggest that safety and reward learning use overlapping mechanisms in the basal amygdala.
authors: Ernest Gallo Clinic and Research Center, University of California at San Francisco, Emeryville, California 94608, USA. susansangha@gmail.com
authors: Susan
authors: S
authors: Sangha
authors: James Z
authors: JZ
authors: Chadick
authors: Patricia H
authors: PH
authors: Janak
mesh_terms: D000161:Acoustic Stimulation; D000200:Action Potentials / Q000502:physiology; D000679:Amygdala / Q000166:cytology / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D003463:Cues; D004597:Electroshock / Q000009:adverse effects; D005239:Fear; D005518:Food Preferences / Q000502:physiology; D008297:Male; D009474:Neurons / Q000145:classification / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D011930:Reaction Time / Q000502:physiology; D012201:Reward