title: Enhancement of Odor Sensitivity Following Repeated Odor and Visual Fear Conditioning.
abstract: Odor detection sensitivity can be rapidly altered by fear conditioning; whether this effect is augmented over time is not known. The present study aimed to test whether repeated conditioning sessions induce changes in odor detection threshold as well as in conditioned responses and whether olfactory stimuli evoke stronger conditioned responses than visual stimuli. The repeated conditioning group participated in repeated sessions over 2 weeks whereas the single conditioning group participated in 1 conditioning session; both groups were presented with visual and olfactory stimuli, were paired with an electric shock (CS+) and 2 matched control stimuli not paired with shock (CS-) while olfactory detection threshold and skin conductance responses (SCRs) were measured before and after the last session. We found increased sensitivity for the CS+ odor in the repeated but not in the single conditioning group, consistent with changes in olfactory sensitivity following repeated aversive learning and of a similar magnitude to what has previously been demonstrated in the periphery. SCR to the visual and olfactory CS+ were similar between groups, indicating that sensory thresholds can change without corresponding change in conditioned responses. In conclusion, repeated conditioning increases detection sensitivity and reduces conditioned responses, suggesting that segregated processes influence perception and conditioned responses.
authors.affiliation: Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA, Department of General Psychology, University of Padova, Via Venezia, 8, 35100 Padova, Italy, Department of Clinical Neuroscience, Karolinska Institutet, Nobels väg 9, 17177 Stockholm, Sweden.
authors.forename: Valentina
authors.initials: V
authors.lastname: Parma
authors.affiliation: Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA, Department of Neuroradiology, Neurological Institute, Carlo Besta, Milan 20133, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Ferraro
authors.affiliation: Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA.
authors.forename: Stacie S
authors.initials: SS
authors.lastname: Miller
authors.affiliation: Department of Clinical Neuroscience, Karolinska Institutet, Nobels väg 9, 17177 Stockholm, Sweden, Department of Psychology, Uppsala University, von Kraemers allé 1A, 751 42 Uppsala, Sweden and.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Åhs
authors.affiliation: Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA, Department of Clinical Neuroscience, Karolinska Institutet, Nobels väg 9, 17177 Stockholm, Sweden, Department of Psychology, University of Pennsylvania, 3720 Walnut Street, Philadelphia, PA 19104, USA johan.lundstrom@ki.se.
authors.forename: Johan N
authors.initials: JN
authors.lastname: Lundström
mesh_terms: D000328:Adult; D003214:Conditioning, Classical / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009812:Odorants; D010775:Photic Stimulation; D055815:Young Adult
keywords: aversive conditioning; odor conditioning; odor sensitivity; visual conditioning