Inhibition of amygdaloid dopamine D 2 receptors impairs emotional learning measured with fear-potentiated startle

Inhibition of amygdaloid dopamine D 2 receptors impairs emotional learning measured with... Considerable advances have been made in understanding the neurocircuitry underlying the acquisition and expression of Pavlovian conditioned fear responses. Within the complex cellular and molecular processes mediating fearfulness, amygdaloid dopamine (DA), originating from cells in the ventral tegmental area (VTA) of the midbrain, is thought to contribute to fear-motivated responding. Considering that blockade of DA D 2 receptors is a common mechanism of action for antipsychotic agents, we hypothesized that inhibition of D 2 receptors in the amygdala may be involved in the antiparanoid effects of these drugs. To assess the role of amygdaloid DA D 2 receptors in aversive emotionality, the D 2 receptor antagonist raclopride was infused into the amygdala prior to Pavlovian fear conditioning. Potentiated startle was used as a behavioral indicator of fear and anxiety. Classical fear conditioning and acoustic startle testing were conducted in a single session allowing for the concomitant assessment of shock reactivity with startle enhancement. Depending on dose, the results found conditioned fear acquisition and retention to be impaired following administration of raclopride into the amygdala. Additionally, the learning deficit was dissociated from shock detection and from fear expression assessed with the shock sensitization of acoustic startle. These findings further refine the known neural mechanisms of amygdala-based emotional learning and memory and were interpreted to suggest that, along with D 1 receptors, D 2 receptors in the amygdala may mediate the formation and the retention of newly-acquired fear associations. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Brain Research Elsevier

Inhibition of amygdaloid dopamine D 2 receptors impairs emotional learning measured with fear-potentiated startle

Brain Research, Volume 899 (1) – Apr 27, 2001

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Publisher
Elsevier
Copyright
Copyright © 2001 Elsevier Science B.V.
ISSN
0006-8993
DOI
10.1016/S0006-8993(01)02243-0
Publisher site
See Article on Publisher Site

Abstract

Considerable advances have been made in understanding the neurocircuitry underlying the acquisition and expression of Pavlovian conditioned fear responses. Within the complex cellular and molecular processes mediating fearfulness, amygdaloid dopamine (DA), originating from cells in the ventral tegmental area (VTA) of the midbrain, is thought to contribute to fear-motivated responding. Considering that blockade of DA D 2 receptors is a common mechanism of action for antipsychotic agents, we hypothesized that inhibition of D 2 receptors in the amygdala may be involved in the antiparanoid effects of these drugs. To assess the role of amygdaloid DA D 2 receptors in aversive emotionality, the D 2 receptor antagonist raclopride was infused into the amygdala prior to Pavlovian fear conditioning. Potentiated startle was used as a behavioral indicator of fear and anxiety. Classical fear conditioning and acoustic startle testing were conducted in a single session allowing for the concomitant assessment of shock reactivity with startle enhancement. Depending on dose, the results found conditioned fear acquisition and retention to be impaired following administration of raclopride into the amygdala. Additionally, the learning deficit was dissociated from shock detection and from fear expression assessed with the shock sensitization of acoustic startle. These findings further refine the known neural mechanisms of amygdala-based emotional learning and memory and were interpreted to suggest that, along with D 1 receptors, D 2 receptors in the amygdala may mediate the formation and the retention of newly-acquired fear associations.

Journal

Brain ResearchElsevier

Published: Apr 27, 2001

References

  • Excitatory amino acids in synaptic transmission in the Schaffer collateral-commissural pathway of the rat hippocampus
    Collingridge, G.L; Kehl, S.J; McLennan, H
  • Amygdala and the memory of reward
    Gaffan, D
  • Neuroleptic reduction of cocaine-induced paranoia but not euphoria?
    Gawin, F.H
  • The involvement of ventral tegmental area cholinergic muscarinic receptors in classically conditioned fear expression as measured with fear-potentiated startle
    Greba, Q; Munro, L.J; Kokkinidis, L
  • Amygdaloid D 1 dopamine receptor involvement in Pavlovian fear conditioning
    Guarraci, F.A; Frohardt, R.J; Kapp, B.S
  • An electrophysiological characterization of ventral tegmental area dopaminergic neurons during differential Pavlovian fear conditioning in the awake rabbit
    Guarraci, F.A; Kapp, B.S
  • Infusion of quinpirole and muscimol into the ventral tegmental area inhibits fear-potentiated startle: implications for the role of dopamine in fear expression
    Munro, L.J; Kokkinidis, L
  • Infusion of the dopamine D 1 receptor antagonist SCH 23390 into the amygdala blocks fear expression in a potentiated startle paradigm
    Waddington Lamont, E; Kokkinidis, L

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