title: Individual trial analysis evidences clock and non-clock based conditioned suppression behaviors in rats.
abstract: We analyzed the temporal pattern of conditioned suppression of lever-pressing for food in rats conditioned with tone-shock pairings using either a 10 or 15s conditioned stimulus (CS)-unconditioned stimulus (US) interval with a CS duration that was three times the CS-US interval. The analysis of average suppression and of individual trials was performed during Probe CS-alone trials and when a short gap was inserted during the CS. The pattern of suppression followed the classical temporal rules: (1) scalar property, (2) a shift in peak suppression due to a gap, compatible with a Stop rule, (3) a three-state pattern of lever-pressing in individual trials, with abrupt start and stop of suppression. The peak of the average suppression curve, but not the middle time, was anticipatory to the programmed US time. The pattern of lever-pressing in individual trials unraveled two types of start of suppression behavior: a clock-based biphasic responding, with a burst of lever-pressing before suppression, and a non-clock based monophasic reduction of lever-pressing close to the CS onset. The non-clock based type of behavior may be responsible for the anticipatory peak time, and the biphasic pattern of lever-pressing may reflect the decision stage described in clock models.
authors.affiliation: Univ Paris-Saclay, Univ Paris-Sud, CNRS, Institut des Neurosciences Paris-Saclay (Neuro PSI), UMR 9197 Orsay, France. Electronic address: lucille.tallot@gmail.com.
authors.forename: Lucille
authors.initials: L
authors.lastname: Tallot
authors.affiliation: Univ Paris-Saclay, Univ Paris-Sud, CNRS, Institut des Neurosciences Paris-Saclay (Neuro PSI), UMR 9197 Orsay, France.
authors.forename: Daphné
authors.initials: D
authors.lastname: Capela
authors.affiliation: Department of Psychology, Queens College and the Graduate Center, The City University of New York, Flushing, NY 11367, USA.
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Brown
authors.affiliation: Univ Paris-Saclay, Univ Paris-Sud, CNRS, Institut des Neurosciences Paris-Saclay (Neuro PSI), UMR 9197 Orsay, France. Electronic address: valerie.doyere@u-psud.fr.
authors.forename: Valérie
authors.initials: V
authors.lastname: Doyère
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D003214:Conditioning, Classical; D003216:Conditioning, Operant; D004597:Electroshock; D005239:Fear / Q000523:psychology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D062211:Spatio-Temporal Analysis; D013997:Time Factors
keywords: Fear conditioning; Gap; Interval timing; Peak procedure; Start/stop