Route of nicotine administration influences in vivo dopamine neuron activity: habituation, needle injection, and cannula infusion

J Mol Neurosci. 2010 Jan;40(1-2):164-71. doi: 10.1007/s12031-009-9231-6.

Abstract

Mesolimbic dopamine (DA) systems play a critical role in tobacco addiction driven by nicotine. Nicotine activates midbrain DA neurons and, consequently, elevates DA concentrations in targets, especially in the nucleus accumbens (NAc) of the ventral striatum. The route of drug administration influences the impact of addictive drugs. Here, we examine whether the nature of the administration alters DA neuron activity and DA concentrations in the NAc. Using unhabituated naïve freely moving rats, microdialysis measurements showed that nicotine administered via needle injection caused greater DA release in the NAc than the same dose administered via an implanted chronic cannula. After habituation to the needle injections, however, there was no significant difference in DA signaling between the needle and cannula routes of administration. Consistent with these microdialysis results after habituation, our in vivo tetrode unit recordings showed no significant difference in midbrain DA neuron activity in response to nicotine delivered by needle or cannula as long as predictive cues were avoided

Publication types

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

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Animals
  • Brain / drug effects*
  • Brain / metabolism
  • Brain / physiopathology*
  • Catheterization
  • Cues
  • Dopamine / metabolism*
  • Drug Administration Routes
  • Extracellular Fluid / drug effects
  • Extracellular Fluid / metabolism
  • Infusion Pumps
  • Injections
  • Male
  • Microdialysis
  • Needles
  • Neurons / drug effects
  • Neurons / metabolism
  • Nicotine / administration & dosage*
  • Nicotinic Agonists / administration & dosage
  • Nucleus Accumbens / drug effects
  • Nucleus Accumbens / metabolism
  • Nucleus Accumbens / physiopathology
  • Rats
  • Rats, Long-Evans
  • Reward
  • Substance-Related Disorders / metabolism
  • Substance-Related Disorders / physiopathology*
  • Tobacco Use Disorder / metabolism
  • Tobacco Use Disorder / physiopathology*
  • Ventral Tegmental Area / drug effects
  • Ventral Tegmental Area / metabolism
  • Ventral Tegmental Area / physiopathology

Substances

  • Nicotinic Agonists
  • Nicotine
  • Dopamine