[Abstract Title]. - Society for Neuroscience

participant in the transcriptional regulation of memory-associated genes during consolidation.
But interestingly, within the hippocampus, the alterations in methylation produced by learning
return to baseline within 24 hours after training, at least in the subset of genes examined to date.
To investigate the possibility that the CNS employs methylation as a more permanent storage
mechanism, methylation was examined in the medial prefrontal cortex (mPFC) or basolateral
amygdala (BLA) 7 days after training for contextual and cued fear conditioning. There were no
differences between trained animals and their control counterparts (context only or shock only)
in the promoters of the immediate early gene zif or the negative regulator of memory,
calcineurin, in the mPFC 7 days after contextual fear conditioning. However, the promoter
region of reelin was hypermethylated in animals that had received associative training a week
earlier. Interestingly, this effect was NMDA receptor-dependent, as treatment with MK-801 at
the time of training prevented the reelin hypermethylation. In contrast, both reelin and
calcineurin were hypomethylated in the BLA one week after cued fear conditioning relative to
controls, while zif was hypermethylated. Taken together, these results demonstrate that a single
trial of fear conditioning is sufficient to produce lasting, gene-specific changes in DNA
methylation. In addition, the rapid methylation changes observed in the hippocampus versus
sustained methylation in the cortex are consistent with the notion that associative memories may
shift from the hippocampus where they are initially consolidated to a more permanent storage
site in the cortex.
Disclosures: C.A. Miller , None; R. Parrish, None; J.D. Sweatt, None.
Poster
294. Gene Expression and Fear Learning
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 294.5/SS45
Topic: F.02.f. Fear and aversive learning and memory
Support: NSF 0444632
New Zealand Tertiary Education Commission
NIH 073949
Title: Auditory thalamic neurons that express early growth response gene 1 (EGR-1) following
fear conditioning project to the lateral amygdala