Centennial Honors College
Western Illinois University
Undergraduate Research Day 2014
Podium Presentation
Disruption of Acetylcholine and Habit Learning:
A Lesser Known Effect of Alzheimer's Disease?
Stephanie Jacobs
Faculty Mentor: Matthew Blankenship
Psychology
Alzheimer's disease (AD) is the most prevalent form of dementia in the world, but still
remains an incurable ailment with no effective treatments. The present study was
aiming to better understand the nature of the disease in terms of characterizing certain
memory impairments that may be associated with it – specifically implicit, or
unconscious, learning and memory tasks. It has been shown that these types of tasks
are associated with the basal ganglia regions of the brain, which are rich in a particular
neurotransmitter known as acetylcholine. It was hypothesized that if acetylcholine
transmission was reduced, rats would not be able to implicitly learn a pattern as they
normally would, standing to answer questions about whether or not these systems are
affected from aging and AD processes. Using a standard operant conditioning box, rats
were trained to learn a well-documented serial reaction task in order to observe pattern
learning. Preliminary results have shown that although the disrupted and control rats
began to learn the tasks at the same rate, after the rats were treated and began the
pattern learning process, the acetylcholine disrupted rats initially performed more
accurately than the control counterparts on a subsequent task – suggesting there was
no pattern learned to interfere with an additional task that required performing new
patterns. These results provide support for the theory that acetylcholine transmission
does play an important role in basal ganglia functioning, which would be impaired in AD
and aging populations, therefore impeding implicit procedural-learning abilities as well.