title: Acute administration of nicotine into the higher order auditory Te2 cortex specifically decreases the fear-related charge of remote emotional memories.
abstract: Nicotine elicits several behavioural effects on mood as well as on stress and anxiety processes. Recently, it was found that the higher order components of the sensory cortex, such as the secondary auditory cortex Te2, are essential for the long-term storage of remote fear memories. Therefore, in the present study, we examined the effects of acute nicotine injection into the higher order auditory cortex Te2, on the remote emotional memories of either threat or incentive experiences in rats. We found that intra-Te2 nicotine injection decreased the fear-evoked responses to a tone previously paired with footshock. This effect was cue- and dose-specific and was not due to any interference with auditory stimuli processing, innate anxiety and fear processes, or with motor responses. Nicotine acts acutely in the presence of threat stimuli but it did not determine the permanent degradation of the fear-memory trace, since memories tested one week after nicotine injection were unaffected. Remarkably, nicotine did not affect the memory of a similar tone that was paired to incentive stimuli. We conclude from our results that nicotine, when acting acutely in the auditory cortex, relieves the fear charge embedded by learned stimuli.
authors: Rita Levi-Montalcini Department of Neuroscience, University of Turin, Corso Raffaello 30, I-10125 Turin, Italy. Electronic address: marco.cambiaghi@unito.it.
authors: Marco
authors: M
authors: Cambiaghi
authors: Rita Levi-Montalcini Department of Neuroscience, University of Turin, Corso Raffaello 30, I-10125 Turin, Italy. Electronic address: anna.grosso@unito.it.
authors: Anna
authors: A
authors: Grosso
authors: Rita Levi-Montalcini Department of Neuroscience, University of Turin, Corso Raffaello 30, I-10125 Turin, Italy. Electronic address: annamaria.renna@unito.it.
authors: Annamaria
authors: A
authors: Renna
authors: Rita Levi-Montalcini Department of Neuroscience, University of Turin, Corso Raffaello 30, I-10125 Turin, Italy. Electronic address: giulia.concina@unito.it.
authors: Giulia
authors: G
authors: Concina
authors: Rita Levi-Montalcini Department of Neuroscience, University of Turin, Corso Raffaello 30, I-10125 Turin, Italy; National Institute of Neuroscience, Italy. Electronic address: benedetto.sacchetti@unito.it.
authors: Benedetto
authors: B
authors: Sacchetti
mesh_terms: D000818:Animals; D001303:Auditory Cortex / Q000187:drug effects* / Q000502:physiology; D001307:Auditory Perception / Q000187:drug effects / Q000502:physiology; D002408:Catheters, Indwelling; D003214:Conditioning, Classical / Q000187:drug effects / Q000502:physiology; D003463:Cues; D004305:Dose-Response Relationship, Drug; D004597:Electroshock; D005239:Fear / Q000187:drug effects* / Q000502:physiology; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology; D008297:Male; D008568:Memory / Q000187:drug effects* / Q000502:physiology; D009538:Nicotine / Q000008:administration & dosage*; D018722:Nicotinic Agonists / Q000008:administration & dosage*; D055696:Olfactory Perception / Q000187:drug effects / Q000502:physiology; D011619:Psychotropic Drugs / Q000008:administration & dosage*; D017208:Rats, Wistar; D013216:Reflex, Startle / Q000187:drug effects / Q000502:physiology
chemical_list: D018722:Nicotinic Agonists; D011619:Psychotropic Drugs; D009538:Nicotine
keywords: Anxiety; Auditory cortex; Fear memory; Incentive memory; Nicotine