Strain differences in the neural, behavioral, and molecular correlates of sweet and salty taste in naive, ethanol- and sucrose-exposed P and NP rats

J Neurophysiol. 2011 Nov;106(5):2606-21. doi: 10.1152/jn.00196.2010. Epub 2011 Aug 17.

Abstract

Strain differences between naive, sucrose- and ethanol-exposed alcohol-preferring (P) and alcohol-nonpreferring (NP) rats were investigated in their consumption of ethanol, sucrose, and NaCl; chorda tympani (CT) nerve responses to sweet and salty stimuli; and gene expression in the anterior tongue of T1R3 and TRPV1/TRPV1t. Preference for 5% ethanol and 10% sucrose, CT responses to sweet stimuli, and T1R3 expression were greater in naive P rats than NP rats. The enhancement of the CT response to 0.5 M sucrose in the presence of varying ethanol concentrations (0.5-40%) in naive P rats was higher and shifted to lower ethanol concentrations than NP rats. Chronic ingestion of 5% sucrose or 5% ethanol decreased T1R3 mRNA in NP and P rats. Naive P rats also demonstrated bigger CT responses to NaCl+benzamil and greater TRPV1/TRPV1t expression. TRPV1t agonists produced biphasic effects on NaCl+benzamil CT responses, enhancing the response at low concentrations and inhibiting it at high concentrations. The concentration of a TRPV1/TRPV1t agonist (Maillard reacted peptides conjugated with galacturonic acid) that produced a maximum enhancement in the NaCl+benzamil CT response induced a decrease in NaCl intake and preference in P rats. In naive P rats and NP rats exposed to 5% ethanol in a no-choice paradigm, the biphasic TRPV1t agonist vs. NaCl+benzamil CT response profiles were higher and shifted to lower agonist concentrations than in naive NP rats. TRPV1/TRPV1t mRNA expression increased in NP rats but not in P rats exposed to 5% ethanol in a no-choice paradigm. We conclude that P and NP rats differ in T1R3 and TRPV1/TRPV1t expression and neural and behavioral responses to sweet and salty stimuli and to chronic sucrose and ethanol exposure.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amiloride / analogs & derivatives
  • Amiloride / pharmacology
  • Anilides / pharmacology
  • Animals
  • Central Nervous System Depressants / pharmacology
  • Chorda Tympani Nerve / physiology
  • Cinnamates / pharmacology
  • Dietary Sucrose / pharmacology*
  • Diterpenes / pharmacology
  • Ethanol / pharmacology*
  • Feeding Behavior / drug effects
  • Feeding Behavior / physiology*
  • Food Preferences / drug effects
  • Food Preferences / physiology*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Models, Biological
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, G-Protein-Coupled / genetics
  • Sodium Chloride, Dietary / pharmacology*
  • Species Specificity
  • TRPV Cation Channels / agonists
  • TRPV Cation Channels / genetics
  • Taste Perception / drug effects
  • Taste Perception / genetics
  • Taste Perception / physiology*
  • Tongue / physiology

Substances

  • Anilides
  • Central Nervous System Depressants
  • Cinnamates
  • Dietary Sucrose
  • Diterpenes
  • N-(3-methoxyphenyl)-4-chlorocinnamanilide
  • Receptors, G-Protein-Coupled
  • Sodium Chloride, Dietary
  • TRPV Cation Channels
  • TRPV1 protein, mouse
  • taste receptors, type 1
  • benzamil
  • Ethanol
  • Amiloride
  • resiniferatoxin