[Abstract Title]. - Society for Neuroscience

To determine the involvement of acetylcholine in dorsolateral prefrontal cortex function, we then
trained these monkeys on the spatial delayed response task (Goldman, 1970; Bachevalier and
Mishkin, 1986) in a manual testing apparatus. In this task the monkey watches as an
experimenter places a small food reward in one of two wells of a test tray and then covers both
wells with identical gray plaques. After a brief delay (1-5 sec) during which an opaque screen is
interposed between the monkey and experimenter, the monkey is allowed to obtain the reward by
displacing the plaque covering the well that was baited by the experimenter. Thus, the monkey
must maintain the baited location (left or right) in memory during the brief delay interval in order
to choose correctly. Performance of this task is devastated by ablation of dorsolateral prefrontal
cortex. The monkeys with cholinergic depletion of lateral and orbital prefrontal cortex were also
unable to learn the task to criterion, which four unoperated control monkeys learned readily.
This finding suggests that acetylcholine, although not critical for functions of ventrolateral and
orbital prefrontal cortex, is essential for dorsolateral prefrontal cortex function. An alternative
explanation, which we are currently investigating, is that acetylcholine is necessary for the
prefrontal cortex to adapt to the different task demands of delayed response, relative to the tests
of discrimination learning with which these monkeys had extensive experience. This would be
consistent with a role for cholinergic input to neocortex in cortical plasticity and remodeling.
Disclosures: M.G. Baxter, None; D.A. Kyriazis, None; P.L. Croxson, None.
Poster
292. Acetylcholine, Neurotrophins, and Cognition
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 292.10/SS23
Topic: F.02.d. Cognitive learning and memory systems
Support: NIDA Grant DA023209 to AM
Title: Mice lacking the β4 subunit of the nicotinic acetylcholine receptor show long-term
memory deficits in hippocampus-dependent tasks
Authors: H. M. JARRELL, S. SEMENOVA, *A. MARKOU;
Psychiatry, Univ. of California, La Jolla, CA
Abstract: Nicotine binds to nicotinic acetylcholine receptors (nAChRs) throughout the brain and
elicits a range of behavioral responses related to cognition, including enhancement of learning
and memory. However, the role of specific nAChRs subtypes in regulating behavior in the
absence of nicotine is still not clear. The present work investigated the role of β4-containing
nAChRs in learning and memory using wildtype (WT, β4 +/+ ) and null mutant (KO, β4 -/- ) mice for