title: Fear conditioning induces guinea pig auditory cortex activation by foot shock alone.
abstract: The present study used an optical imaging paradigm to investigate plastic changes in the auditory cortex induced by fear conditioning, in which a sound (conditioned stimulus, CS) was paired with an electric foot-shock (unconditioned stimulus, US). We report that, after conditioning, auditory information could be retrieved on the basis of an electric foot-shock alone. Before conditioning, the auditory cortex showed no response to a foot-shock presented in the absence of sound. In contrast, after conditioning, the mere presentation of a foot-shock without any sound succeeded in eliciting activity in the auditory cortex. Additionally, the magnitude of the optical response in the auditory cortex correlated with variation in the electrocardiogram (correlation coefficient: -0.68). The area activated in the auditory cortex, in response to the electric foot-shock, statistically significantly had a larger cross-correlation value for tone response to the CS sound (12 kHz) compared to the non-CS sounds in normal conditioning group. These results suggest that integration of different sensory modalities in the auditory cortex was established by fear conditioning.
authors.affiliation: Tamagawa University Brain Science Institute, 6-1-1 Tamagawa-gakuen, Machida, Tokyo 194-8610 Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ide
authors.affiliation: Tamagawa University Brain Science Institute, 6-1-1 Tamagawa-gakuen, Machida, Tokyo 194-8610 Japan ; Graduate School of Systems Life Sciences, Kyushu University, Fukuoka, 819-0395 Japan.
authors.forename: Muneyoshi
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Tamagawa University Brain Science Institute, 6-1-1 Tamagawa-gakuen, Machida, Tokyo 194-8610 Japan ; Graduate School of Systems Life Sciences, Kyushu University, Fukuoka, 819-0395 Japan.
authors.forename: Johan
authors.initials: J
authors.lastname: Lauwereyns
authors.affiliation: Faculty of Medicine, Louis Pasteur University, 67085 Strasbourg, France.
authors.forename: Guy
authors.initials: G
authors.lastname: Sandner
authors.affiliation: Tamagawa University Brain Science Institute, 6-1-1 Tamagawa-gakuen, Machida, Tokyo 194-8610 Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Tsukada
authors.affiliation: Tamagawa University Brain Science Institute, 6-1-1 Tamagawa-gakuen, Machida, Tokyo 194-8610 Japan ; Faculty of Engineering, Tamagawa University, Tokyo, 194-8610 Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Aihara
keywords: Acetylcholine; Cross-modal; Optical imaging; Plasticity; Voltage sensitive dye