Norepinephrine infused into the basolateral amygdala posttraining enhances retention in a spatial water maze task

Neurobiol Learn Mem. 1999 Mar;71(2):232-9. doi: 10.1006/nlme.1998.3875.


Recent evidence indicates that the amygdala plays a role in modulating memory processes in other brain regions. For example, posttraining intra-amygdala infusions of amphetamine enhanced memory in both spatial and cued training water maze tasks; these tasks are known to depend on the integrity of the hippocampus and caudate nucleus, respectively. To determine whether this modulation is dependent on noradrenergic activation within a subregion of the amygdala (the basolateral nucleus), the present study examined the effects of posttraining microinfusions (0.2 microl) of norepinephrine or propranolol into the basolateral amygdala immediately following training in a spatial version of the water maze task. Rats received a four-trial training session on each of 2 consecutive days. On the third day, rats were given a 60-s probe test in the absence of a platform. Retention latencies obtained on the second training day revealed that norepinephrine dose-dependently enhanced retention for the location of the hidden platform. In contrast, propranolol significantly impaired retention. Probe trial analysis revealed that rats treated with 0.25 microg norepinephrine demonstrated a selective spatial bias for the training platform location relative to all other groups. These findings are consistent with others and support the view that the basolateral amygdala has a role in modulating memory storage by interacting with other brain regions.

Publication types

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

MeSH terms

  • Amygdala / drug effects*
  • Animals
  • Maze Learning / drug effects*
  • Norepinephrine / pharmacology*
  • Propranolol / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Retention, Psychology / drug effects*
  • Spatial Behavior / drug effects*
  • Sympatholytics / pharmacology
  • Time Factors
  • Water


  • Sympatholytics
  • Water
  • Propranolol
  • Norepinephrine