[Abstract Title]. - Society for Neuroscience

NIDA Training Grant DA07237, JWK
Title: Towards an understanding of how nicotinic acetylcholine receptors modulate
hippocampus dependent learning and memory
Authors: *J. W. KENNEY, T. J. GOULD;
Dept Psychol/Neurosci, Temple Univ., Philadelphia, PA
Abstract: Nicotine is known to enhance learning and memory in a variety of hippocampus
dependent tasks. In particular, the enhancement of contextual fear conditioning and related tasks
by nicotine has proven useful in delineating the neurobiological substrates that underlie the effect
of nicotine on learning and memory. For nicotine to enhance contextual fear memories the drug
must be administered prior to both training and recall in these tasks. In an effort to understand
why nicotine must be administered at both of these time points we have developed a hypothesis
as to how nicotine alters hippocampal-cortical-amygdala interactions that stems from the work of
Rudy and colleagues (2004) and Fanselow (1999, 2000). We hypothesize that training in
contextual fear tasks in the presence of nicotine results in the alteration of hippocampal-corticalamygdala
connectivity such that a pathway that is not critically involved in the formation of a
short-term contextual fear memory is recruited. This additional pathway then summates with the
usual hippocampal-amygdala pathway that normally underlies the formation of the contextual
fear memory resulting in the enhanced memory. For the alteration in hippocampal-corticalamygdala
connective strength to occur we hypothesize that nicotine 1) increases hippocampalcortical
connectivity during context learning and recall and 2) reduces hippocampal inhibition of
the cortical input to the amygdala, an inhibition that is postulated to exist based on experimental
data discussed by Rudy et al (2004). This modified model is capable of explaining why nicotine
must be administered prior to both learning and recall to enhance contextual fear memories and
makes various novel predictions. If accurate, this model will further our understanding of how
nicotine alters contextual information processing that may play an important role in a number of
cognitive disorders such as addiction.
Disclosures: J.W. Kenney , None; T.J. Gould, None.
Poster
291. Animal Cognition and Behavior: Learning and Memory: Pharmacology II
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 291.16/RR91
Topic: F.02.j. Learning and memory: Pharmacology
Support: NIDA Grant DA017949