Effects of nicotine on odor-induced increases in regional blood flow in the olfactory bulb in rats

J Physiol Sci. 2019 Mar;69(2):425-431. doi: 10.1007/s12576-018-00657-2. Epub 2019 Jan 1.

Abstract

The present study examined the effects of nicotinic acetylcholine receptor activation on the odor-induced blood flow response in the olfactory bulb. In urethane-anesthetized rats, odor stimulation (5% amyl acetate, 30 s) produced an increase in olfactory bulb blood flow (reaching 107% ± 3% of the pre-stimulus basal values), without changes in frontal cortical blood flow or mean arterial pressure. Intravenous injection of nicotine (30 μg/kg), a nicotinic acetylcholine receptor agonist, significantly augmented the odor-induced increase response of olfactory bulb blood flow, without changes in the basal blood flow level. The nicotine-induced augmentation of the olfactory bulb blood flow response to odor was negated by dihydro-β-erythroidine, an α4β2-preferring nicotinic acetylcholine receptor antagonist. Our results suggest that the activation of α4β2-like neuronal nicotinic acetylcholine receptors in the brain potentiates an odor-induced blood flow response in the olfactory bulb.

Keywords: Nicotinic acetylcholine receptor; Odor stimulation; Olfactory bulb; Rat; Regional cerebral blood flow.

MeSH terms

  • Animals
  • Male
  • Nicotine / pharmacology*
  • Nicotinic Antagonists / pharmacology
  • Odorants
  • Olfactory Bulb / drug effects*
  • Olfactory Bulb / metabolism
  • Rats
  • Rats, Wistar
  • Receptors, Nicotinic / metabolism
  • Regional Blood Flow / drug effects*

Substances

  • Nicotinic Antagonists
  • Receptors, Nicotinic
  • Nicotine

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