Aryl hydrocarbon receptor is indispensable for β-naphthoflavone-induced novel food avoidance and may be involved in LiCl-triggered conditioned taste aversion in rats

Raimo Pohjanvirta, Selma Mahiout

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Previous studies have shown that several aryl hydrocarbon receptor (AHR) agonists, including β-naphthoflavone (BNF), elicit avoidance of novel food items in rodents, with this behavioral response displaying a similar doseresponse to hepatic induction of CYP1A1. The avoidance has been found to bear substantial similarity to conditioned taste avoidance/aversion (CTA). The present study set out to confirm the indispensability of AHR in the avoidance response, to verify whether vagal afferent fibers are involved in it, and to see if AHR signaling might interfere with the effect of the classic trigger of CTA, LiCl. To this end, globally AHR deficient (AHRKO) or vagotomized wildtype rats were treated by gavage with 60 mg/kg BNF or ip with 0.15M LiCl (4 ml/kg), and presented with chocolate which was either novel or familiar to them. Both the avoidance response and Cyp1a1 induction were missing in AHRKO rats. In contrast, Ahr+/− rats exhibited them in full, save for a single outlier. Total subdiaphragmatic vagotomy failed to interfere with the avoidance of novel or familiar chocolate or induction of Cyp1a1. After LiCl administration, male AHRKO rats showed a significantly mitigated suppression of chocolate consumption compared with wildtype animals (~60% vs. ~10% of control chocolate intake, respectively). A similar tendency was seen in females, but they were less responsive to LiCl. These findings corroborate AHR as a prerequisite of the BNF-induced novel food avoidance, prove vagal afferents unlikely mediators of this response, and imply an unforeseen involvement of AHR signaling in the thoroughly-characterized CTA instigated by LiCl.
Original languageEnglish
JournalPhysiology & Behavior
Volume204
Pages (from-to)58-64
Number of pages7
ISSN0031-9384
DOIs
Publication statusPublished - 15 May 2019
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN
  • ACQUISITION
  • AH RECEPTOR
  • AHR knockout rats
  • Aryl hydrocarbon receptor
  • BRAIN
  • Conditioned taste aversion
  • INDUCTION
  • LiCl
  • MICE
  • NEURONS
  • Novel food avoidance
  • PARABRACHIAL NUCLEUS
  • SUBDIAPHRAGMATIC VAGOTOMY
  • TOXICITY
  • Total subdiaphragmatic vagotomy
  • Vagotomized rats
  • beta-Naphthoflavone
  • 416 Food Science
  • 413 Veterinary science

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