Restricted access to standard or high fat chow alters sensitivity of rats to the 5-HT(2A/2C) receptor agonist 1-(2,5-dimethoxy-4-methylphenyl)-2-aminopropane

Behav Pharmacol. 2014 Feb;25(1):44-52. doi: 10.1097/FBP.0000000000000015.


Feeding conditions can impact sensitivity to drugs acting on dopamine receptors; less is known about the impact of feeding conditions on the effects of drugs acting on serotonin (5-HT) receptors. This study examined the effects of feeding conditions on sensitivity to the direct-acting 5-HT(2A/2C) receptor agonist 1-(2,5-dimethoxy-4-methylphenyl)-2-aminopropane (DOM; 0.1-3.2 mg/kg) and the direct-acting dopamine D3/D2 receptor agonist quinpirole (0.0032-0.32 mg/kg). Male Sprague-Dawley rats had free access (11 weeks), followed by restricted access (6 weeks), to high fat (34.3%, n=8) or standard (5.7% fat; n=7) chow. Rats eating high fat chow became insulin resistant and gained more weight than rats eating standard chow. Free access to high fat chow did not alter sensitivity to DOM-induced head twitch but increased sensitivity to quinpirole-induced yawning. Restricting access to high fat or standard chow shifted the DOM-induced head twitch dose-response curve to the right and shifted the quinpirole-induced yawning dose-response curve downward in both groups of rats. Some drugs of abuse and many therapeutic drugs act on 5-HT and dopamine systems; these results show that feeding conditions impact sensitivity to drugs acting on these systems, thereby possibly affecting vulnerability to abuse, as well as the therapeutic effectiveness of drugs.

Publication types

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

MeSH terms

  • 2,5-Dimethoxy-4-Methylamphetamine / pharmacology*
  • Animals
  • Blood Glucose / drug effects
  • Body Temperature / drug effects
  • Body Weight / drug effects
  • Diet, High-Fat*
  • Dopamine Agonists / pharmacology
  • Dose-Response Relationship, Drug
  • Feeding Behavior / drug effects*
  • Head Movements / drug effects
  • Insulin / pharmacology
  • Insulin Resistance / physiology
  • Male
  • Quinpirole / pharmacology
  • Rats
  • Serotonin Receptor Agonists / pharmacology*
  • Time Factors
  • Yawning / drug effects


  • Blood Glucose
  • Dopamine Agonists
  • Insulin
  • Serotonin Receptor Agonists
  • 2,5-Dimethoxy-4-Methylamphetamine
  • Quinpirole