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J Psychopharmacol. 2018 Mar;32(3):367-372. doi: 10.1177/0269881118758305. Epub 2018 Mar 1.

Tyrosine receptor kinase B receptor activation reverses the impairing effects of acute nicotine on contextual fear extinction.

Author information

1
1 Department of Biobehavioral Health, Pennsylvania State University, USA.
2
2 Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, USA.
3
3 Department of Neuroscience, University of Pennsylvania Medical School, Philadelphia, USA.

Abstract

Anxiety and stress disorders have been linked to deficits in fear extinction. Our laboratory and others have demonstrated that acute nicotine impairs contextual fear extinction, suggesting that nicotine exposure may have negative effects on anxiety and stress disorder symptomatology. However, the neurobiological mechanisms underlying the acute nicotine-induced impairment of contextual fear extinction are unknown. Therefore, based on the previous studies showing that brain-derived neurotrophic factor is central for fear extinction learning and acute nicotine dysregulates brain-derived neurotrophic factor signaling, we hypothesized that the nicotine-induced impairment of contextual fear extinction may involve changes in tyrosine receptor kinase B signaling. To test this hypothesis, we systemically, intraperitoneally, injected C57BL/6J mice sub-threshold doses (2.5 and 4.0 mg/kg) of 7,8-dihydroxyflavone, a small-molecule tyrosine receptor kinase B agonist that fully mimics the effects of brain-derived neurotrophic factor, or vehicle an hour before each contextual fear extinction session. Mice also received injections, intraperitoneally, of acute nicotine (0.18 mg/kg) or saline 2-4 min before extinction sessions. While the animals that received only 7,8-dihydroxyflavone did not show any changes in contextual fear extinction, 4.0 mg/kg of 7,8-dihydroxyflavone ameliorated the extinction deficits in mice administered acute nicotine. Overall, these results suggest that acute nicotine-induced impairment of context extinction may be related to a disrupted brain-derived neurotrophic factor signaling.

KEYWORDS:

Nicotine; brain-derived neurotrophic factor; extinction; post-traumatic stress disorder; tyrosine receptor kinase B receptors

PMID:
29493350
DOI:
10.1177/0269881118758305

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