[Abstract Title]. - Society for Neuroscience

to in vivo microdialysis to measure glutamate release using a capillary electrophoresis method
based on micellar electrokinetic chromatography (MECK). The results showed a transient 200%
extracellular glutamate increase immediately after LiCl injection but not during the CS
presentation. To our surprise a significant off-line transient release of glutamate occurred 50
minutes after pairing saccharin with LiCl but not after saccharin followed by NaCl. Furthermore,
animals trained with backward conditioning (CS presentation after the US, that is ineffective for
CTA memory formation) did not present any off-line glutamate release in post-training fractions.
To evaluate the further role of the off-line glutamate release in memory consolidation, we
infused an NMDA receptor antagonist (DL-2-amino-5-phosphonovaleric acid, APV) just before
the second transient glutamate release. The results showed a significant impairment in long, but
not in short-term memory. Altogether this evidence points out that off-line NMDA receptor reactivation
seems to be necessary for CTA memory consolidation.
Disclosures: K.R. Guzman-Ramos , None; V. Diaz-Medina, None; R. Bautista, None; F.
Bermúdez-Rattoni, None.
Poster
295. Memory Consolidation, Reconsolidation, Anatomy, and Mechanisms
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 295.22/SS72
Topic: F.02.h. Memory modulation, consolidation, and reconsolidation
Support: NIMH Grant MH069558
NIMH Grant MH060668
Title: Acute corticosterone treatment following fear memory retrieval has divergent results
dependent upon the length of the retrieval session
Authors: *M. E. LONERGAN, F. J. HELMSTETTER;
Psychology, Univ. Wisconsin-Milw, Milwaukee, WI
Abstract: Acute administration of corticosterone has previously been shown to enhance memory
consolidation of conditional fear via noradrenergic signaling in the amygdala (Cordero & Sandi,
1998; Hui et al., 2004; reviewed in McGaugh & Roozendaal, 2002). More recent studies have
explored the effect of corticosterone given at the time of memory retrieval. Corticosterone given
prior to retrieval results in impaired memory recall, whereas, post-retrieval corticosterone
appears to enhance extinction learning (Cai et al., 2006). The post-retrieval effects of
corticosterone hold promise in developing therapeutic treatments for individuals suffering from