Antagonism of lateral amygdala alpha1-adrenergic receptors facilitates fear conditioning and long-term potentiation

Learn Mem. 2010 Sep 24;17(10):489-93. doi: 10.1101/lm.1918210. Print 2010 Oct.

Abstract

Norepinephrine receptors have been studied in emotion, memory, and attention. However, the role of alpha1-adrenergic receptors in fear conditioning, a major model of emotional learning, is poorly understood. We examined the effect of terazosin, an alpha1-adrenergic receptor antagonist, on cued fear conditioning. Systemic or intra-lateral amygdala terazosin delivered before conditioning enhanced short- and long-term memory. Terazosin delivered after conditioning did not affect consolidation. In vitro, terazosin impaired lateral amygdala inhibitory postsynaptic currents leading to facilitation of excitatory postsynaptic currents and long-term potentiation. Since alpha1 blockers are prescribed for hypertension and post-traumatic stress disorder, these results may have important clinical implications.

Publication types

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

MeSH terms

  • Adrenergic alpha-1 Receptor Antagonists / administration & dosage
  • Adrenergic alpha-1 Receptor Antagonists / pharmacology*
  • Amygdala / cytology
  • Amygdala / drug effects*
  • Animals
  • Conditioning, Psychological / drug effects*
  • Cues
  • Electric Stimulation
  • Electrophysiological Phenomena
  • Excitatory Postsynaptic Potentials / drug effects
  • Fear / drug effects*
  • In Vitro Techniques
  • Injections
  • Injections, Intraperitoneal
  • Long-Term Potentiation / drug effects*
  • Male
  • Neurons / drug effects
  • Patch-Clamp Techniques
  • Prazosin / administration & dosage
  • Prazosin / analogs & derivatives*
  • Prazosin / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Stimulation, Chemical

Substances

  • Adrenergic alpha-1 Receptor Antagonists
  • Terazosin
  • Prazosin