Effect of Adolescent Nicotine Exposure on Hippocampus-Dependent Trace Conditioning

I began research in Dr. Robert Barnet’s lab as a Junior, Spring 2011 semester. Dr. Barnet’s research involves basic processes of learning and memory, and the neural basis of learning and memory.  My research will study how exposure to nicotine affects brain and cognitive function.

Nicotine acts as an agonist on nicotinic acetylcholine receptors that are spread throughout the brain, including regions that are critical for learning and memory such as the hippocampus and cerebral cortex. Adolescent nicotinic exposure acts on these receptors and can cause cell death, alteration and degeneration of neural pathways. Research previously conducted in my laboratory suggests that nicotine exposure during adolescence can impair one kind of hippocampus-dependent learning called context conditioning (the ability to learn about situational cues).

Another form of hippocampus-dependent learning is called trace conditioning, in which two events are presented together (e.g. A+B), but separated by a temporal gap (e.g. A—B).  The ability to learn an association between two events in this type of trace conditioning paradigm is also dependent on the hippocampus. My summer research will examine whether nicotine exposure during adolescence impairs the ability to learn in the trace conditioning task.  If it does, this would suggest that nicotine during adolescence impairs hippocampus function that is important to memory.  My research will additionally ask whether any observed memory impairments are long lasting and persist into adulthood.