Olfactory associative conditioning in infant rats with brain stimulation as reward: II. Norepinephrine mediates a specific component of the bulb response to reward

Behav Neurosci. 1991 Dec;105(6):843-9. doi: 10.1037//0735-7044.105.6.843.

Abstract

One of the circuits modified by early olfactory learning is in the olfactory bulb. Specifically, response patterns of mitral-tufted cells are modified by associative conditioning during the early postnatal period. In addition, previous work has demonstrated that mitral-tufted cell single units respond to both olfactory conditioned stimuli and rewarding stimulation of the medial forebrain bundle-lateral hypothalamus (MFB-LH). The present study suggests that norepinephrine beta-receptor activation is required for early olfactory learning using MFB-LH stimulation as reward. Propranolol injected before odor-MFB-LH pairings blocks the acquisition of conditioned behavioral responses and their neural correlates to the conditioned odor. Furthermore, propranolol blocks a specific class of the mitral-tufted cell responses to MFB-LH reward stimulation. The relationship of this response to reward and early learning is discussed.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aging / physiology*
  • Animals
  • Animals, Newborn / physiology
  • Arousal / physiology*
  • Brain Mapping
  • Conditioning, Classical / physiology*
  • Electric Stimulation
  • Female
  • Hypothalamic Area, Lateral / physiology
  • Male
  • Medial Forebrain Bundle / physiology
  • Motivation*
  • Neuronal Plasticity / physiology*
  • Neurons / physiology
  • Norepinephrine / physiology
  • Olfactory Bulb / physiology*
  • Olfactory Pathways / physiology
  • Rats
  • Rats, Inbred Strains
  • Reward
  • Smell / physiology*
  • Synaptic Transmission / physiology

Substances

  • Norepinephrine