Synthesizing Memory

Learning and memory

Learning is the strengthening of existing responses or formation of new responses to existing stimuli that occurs because of

practice or repetition.

Memory has to do with keeping “knowledge” someplace and then retrieving

it when it is needed.

• Test whether CREB-mediated positive feedback plays a central role in learning and memory in C. elegans.

CREB

Diagram modified from Caroline M. Ajo-Franklin, David A. Drubin, Julian A. Eskin, Elaine P.S. Gee, Dirk Landgraf, Ira Phillips and Pamela A. Silver. Genes & Dev. 2007 21: 2271-2276

How to assess learning and memory in C. elegans?

                                                                                                                                As part of an experiment to assess learning and memory in C. elegans roundworms, the image on the left shows worms that have not yet been trained to associate food with a drop of the chemical butanone that has been placed on the right side of the Petri dish. After training, the worms in the image on the right can be seen clustering around butanone that has been added. By testing normal worms as well as worms with genetic mutations that increase lifespan, the researchers were able to explore how factors that extend longevity affect learning and memory. (Credit: Coleen Murphy lab)

Strategy

CREB

Modeling

• Pam Silver cooperativity and bistability

Learning and memory assay

Positive associative olfactory learning and memory assays:Well-fed worms are starved, then fed in the presence of 10% butanone; testing immediately after a

single (massed) training measures learning, and short-term associative memory (STAM) is measured after an interval without exposure to butanone. Long-term associative memory (LTAM) is measured after several intervals of (spaced) training.

Figure from Amanda L. Kauffman1,2, Jasmine M. Ashraf1,2, M. Ryan Corces-Zimmerman1,2, Jessica N. Landis1,2, Coleen T. Murphy1,2*. 2010, PLOS Biology

Predicted outcomes

•Engage undergraduates in multidisciplinary research•Have fun•Check if creb-mediated positive feedback correlates with learning and memory.•Investigate which neurons in a network mediate this phenomenon