Amygdalar and Hippocampal Theta Rhythm Synchronization during Fear Memory Retrieval

• Published in: Science (American Association for the Advancement of Science) Vol. 301; no. 5634; pp. 846 - 850
• Main Authors: Seidenbecher, Thomas, Laxmi, T. Rao, Stork, Oliver, Pape, Hans-Christian
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 08.08.2003; The American Association for the Advancement of Science
• Subjects: Amygdala; Amygdala (Brain); Amygdala - physiology; Animals; Behavior, Animal; Behavioral neuroscience; Behavioral psychophysiology; Biological and medical sciences; Cell death; Classical Conditioning; Conditioning (Psychology); Correlation; Cues; Electrophysiology; Electroshock; Fear; Fear & phobias; Freezing; Fundamental and applied biological sciences. Psychology; Hippocampus; Hippocampus (Brain); Hippocampus - physiology; Male; Memory; Mental stimulation; Mice; Mice, Inbred C57BL; Motor Activity; Neurons; Neuroscience; Physiological aspects; Psychological aspects; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Recall (Psychology); Risk Assessment; Stimuli; Theta Rhythm; Memory retrieval; Amygdala; Electrical activity; Memory; Rodentia; Central nervous system; Electrophysiology; Basal ganglion; Synchronization; Encephalon; Fear; Vertebrata; Mammalia; Mouse; Animal; Theta rhythm; Behavior; Conditioning; Tonic immobility; Hippocampus
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1085818

The amygdalohippocampal circuit plays a pivotal role in Pavlovian fear memory. We simultaneously recorded electrical activity in the lateral amygdala (LA) and the CA1 area of the hippocampus in freely behaving fear-conditioned mice. Patterns of activity were related to fear behavior evoked by conditioned and indifferent sensory stimuli and contexts. Rhythmically synchronized activity at theta frequencies increased between the LA and the CA1 after fear conditioning and became significant during confrontation with conditioned fear stimuli and expression of freezing behavior. Synchronization of theta activities in the amygdalohippocampal network represents a neuronal correlate of conditioned fear, apt to improve neuronal communication during memory retrieval.