Noradrenergic but not cholinergic modulation of olfactory bulb during processing of near threshold concentration stimuli

Behav Neurosci. 2012 Oct;126(5):720-8. doi: 10.1037/a0030006.


Neuromodulatory systems such as noradrenaline (NE), acetylcholine (ACh), and serotonin (5HT) serve important functions in sensory perception. We use the olfactory bulb (OB) as a model system to study the roles of individual neuromodulators in sensory perception. Using a spontaneous, nonreward motivated detection task, as well as a reward-motivated task, we show that rats can easily respond to odorants at very low concentrations when motivated to do so in a food-rewarded task, despite not showing spontaneous responses to these low concentration odorants. Using the same tasks paired with local bulbar infusions of noradrenergic and cholinergic drugs, we then show that rats engage their noradrenergic, but not their cholinergic system, to better respond to near threshold odorants. These results suggest that while cholinergic modulation of OB function is mostly important for odor decorrelation and discrimination, noradrenergic modulation is important for signal-to-noise modulation.

Publication types

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

MeSH terms

  • Aconitine / analogs & derivatives
  • Aconitine / pharmacology
  • Adrenergic alpha-Antagonists / pharmacology
  • Adrenergic beta-Antagonists / pharmacology
  • Alprenolol / pharmacology
  • Animals
  • Carbachol / pharmacology*
  • Choice Behavior / drug effects
  • Cholinergic Agonists / pharmacology*
  • Habituation, Psychophysiologic / drug effects
  • Male
  • Muscarinic Antagonists / pharmacology
  • Nicotinic Antagonists / pharmacology
  • Norepinephrine / pharmacology*
  • Odorants*
  • Olfactory Bulb / drug effects*
  • Olfactory Perception / drug effects*
  • Phentolamine / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Scopolamine / pharmacology
  • Sensory Thresholds / drug effects


  • Adrenergic alpha-Antagonists
  • Adrenergic beta-Antagonists
  • Cholinergic Agonists
  • Muscarinic Antagonists
  • Nicotinic Antagonists
  • methyllycaconitine
  • Alprenolol
  • Carbachol
  • Scopolamine
  • Norepinephrine
  • Aconitine
  • Phentolamine