Noradrenergic and locus coeruleus modulation of the perforant path-evoked potential in rat dentate gyrus supports a role for the locus coeruleus in attentional and memorial processes

Prog Brain Res. 1991;88:307-21. doi: 10.1016/s0079-6123(08)63818-2.

Abstract

The perforant path-dentate gyrus synapse has provided a model system for functional neural plasticity in adult mammalian brain. NMDA-dependent long-term changes in neural connectivity occur at this synapse in response to high-frequency input. Norepinephrine (NE) applied exogenously or released endogenously can initiate both a short- and a long-term potentiation (LTP) of the dentate gyrus response to perforant path input. Triggering of the potentiated response depends on beta-receptor activation and does not require a high-frequency stimulus. An increase in locus coeruleus (LC) activity can initiate both short and LTP of the perforant path response, although a reduction in LC activity does not alter baseline perforant path responses. This chapter considers differences between NE modulation in vitro and in vivo, differences and similarities between NE-LTP and frequency-induced LTP, and the surprising specificity of NE effects at the perforant path synapse. Studies of NE in the dentate gyrus support a role for the LC in promoting both short- and long-term enhancement of responses to complex sensory inputs and are consistent with a role for the LC in memorial as well as attentional processes.

Publication types

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

MeSH terms

  • Animals
  • Association Learning / physiology*
  • Attention / physiology*
  • Evoked Potentials / drug effects
  • Excitatory Amino Acid Antagonists
  • Glutamates / pharmacology
  • Glutamic Acid
  • Hippocampus / physiology*
  • Locus Coeruleus / drug effects
  • Locus Coeruleus / physiology*
  • Memory / physiology*
  • Models, Neurological
  • Neuronal Plasticity / physiology
  • Norepinephrine / physiology*
  • Propranolol / pharmacology
  • Rats
  • Receptors, N-Methyl-D-Aspartate / physiology
  • Synapses / physiology

Substances

  • Excitatory Amino Acid Antagonists
  • Glutamates
  • Receptors, N-Methyl-D-Aspartate
  • Glutamic Acid
  • Propranolol
  • Norepinephrine