Poster C75, Sunday, March 25, 1:00-3:00 pm, Exhibit Hall C
The Impact of Acetylcholine Blockade on Declarative and Motor Memory Consolidation Following a Night of Sleep or a Day of Wake
Matthew Tucker1, Kathryn Taylor1, Rozina Merchant1, Sharon George1, Caroline Stoddard1, Kevin Kopera1; 1University of South Carolina School of Medicine Greenville
It is hypothesized that elevated acetylcholine (ACH) in the brain enhances initial learning of new information, while decreased ACH facilitates memory consolidation (the strengthening of long term memories that follows initial learning)(Hasselmo, 1999; Hasselmo & McGaughy, 2004). ACH is elevated while awake and decreased during sleep (especially slow wave sleep), implicating wake as a time for the acquisition of new information, and sleep as a time for memory consolidation. We examined whether decreasing ACH (scopolamine .4mg) in sleep and wake benefits memory consolidation of newly learned picture pairs and typing speed. Eighty seven college students trained on a visual paired associates task (hippocampus-dependent declarative memory) and a text passage typing test (motor memory) in the morning (9am) or evening (9pm). After training subjects were administered a scopolamine or placebo capsule, which was followed by a night of sleep or a day awake. Subjects were retested on the same tasks 12hrs following the training session. We found that sleep had a beneficial effect on declarative memory processing. However, there was no benefit of scopolamine on declarative memory consolidation. Sleep and scopolamine had no impact on motor memory consolidation. As expected, the side effects of scopolamine, while mild, were significantly more pronounce in the wake subjects, who would have been conscious of those effects. The results of this study call into question the idea that acetylcholine blockade during the memory consolidation phase is beneficial for declarative memory processing.
Topic Area: LONG-TERM MEMORY: Semantic