A role of CB1R in inducing θ-rhythm coordination between the gustatory and gastrointestinal insula

Sci Rep. 2016 Sep 1:6:32529. doi: 10.1038/srep32529.

Abstract

Anandamide (AEA) and N-oleoylethanolamine (OEA) are produced in the intestine and brain during fasting and satiety, respectively. Subsequently, AEA facilitates food intake via activation of cannabinoid type-1 receptors (CB1Rs) while OEA decreases food intake via activation of peroxisome proliferator-activated receptor-α (PPARα) and/or G-protein-coupled receptor 119 (GPR119). Neuronal activity in the gastrointestinal region of the autonomic insula (GI-Au-I) that rostrally adjoins the gustatory insula (Gu-I) increases during fasting, enhancing appetite while umami and sweet taste sensations in Gu-I enhances appetite in GI-Au-I, strongly suggesting the presence of a neural interaction between the Gu-I and GI-Au-I which changes depending on the concentrations of AEA and OEA. However, this possibility has never been investigated. In rat slice preparations, we demonstrate with voltage-sensitive dye imaging that activation of CB1Rs by AEA induces θ-rhythm oscillatory synchronization in the Gu-I which propagates into the GI-Au-I but stops at its caudal end, displaying an oscillatory coordination. The AEA-induced oscillation was abolished by a CB1R antagonist or OEA through activation of GPR119. Our results demonstrate that the neural coordination between the Gu-I and GI-Au-I is generated or suppressed by the opposing activities between CB1R and GPR119. This mechanism may be involved in the feeding behavior based on taste recognition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohol Oxidoreductases / genetics*
  • Alcohol Oxidoreductases / metabolism
  • Animals
  • Appetite / physiology
  • Arachidonic Acids / metabolism
  • Cerebral Cortex / physiology
  • Eating / physiology
  • Endocannabinoids / metabolism
  • Ethanolamines / metabolism
  • Fasting / physiology*
  • Feeding Behavior / physiology
  • Female
  • Gene Expression
  • Intestines / physiology
  • Male
  • Neurons / cytology
  • Neurons / metabolism
  • Oleic Acids / metabolism
  • Polyunsaturated Alkamides / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Rats, Wistar
  • Receptors, G-Protein-Coupled / genetics*
  • Receptors, G-Protein-Coupled / metabolism
  • Satiation / physiology*
  • Signal Transduction
  • Taste Perception / physiology*
  • Theta Rhythm / physiology*

Substances

  • Arachidonic Acids
  • Endocannabinoids
  • Ethanolamines
  • GPR119 protein, rat
  • Oleic Acids
  • Polyunsaturated Alkamides
  • Receptors, G-Protein-Coupled
  • N-oleoylethanolamine
  • Alcohol Oxidoreductases
  • carbonyl reductase 1, mouse
  • anandamide