Understanding learning and memory is one of the great challenges of neuroscience, and olfactory learning and memory is only a small corner of a field dominated by work in hippocampus, amygdala, cerebellum, and prefrontal cortex (physiologically).  What we seek to contribute to this larger field is a rich and effective way to study naturalistic, repetitive, representational learning.   Much of what is known about the cellular mechanisms of learning comes from the very efficient one-trial learning paradigms of fear conditioning.  Based on the findings of these studies, we seek to study the more gradual, conditional learning of everyday experience, primarily via the learning of odor-reward associations paired with experimental interventions.  Also, olfactory learning can be studied as representational learning; that is, as a given odor is progressively learned, it is possible to observe the corresponding changes in the ensemble of neurons that it activates and to infer what these changes imply (for example, is it simply the most weakly-activated neurons that are being shut down, or is it the neurons that convey the least useful information for distinguishing an odor from a similar odor with different implications)?

Presently, we are studying the odor learning-dependent activation of immediate-early genes (c-Fos and Egr1), the timecourses of multiple learning-dependent cascades that may determine the persistence of memory (including the determination of whether, and to what extent, to construct protein synthesis-dependent long-term memories), and the local amnestic effects of isoflurane and related mechanisms within OB.  Our techniques include behavioral pharmacology, thin-section immunohistochemistry, and quantitative RT-PCR to measure mRNA transcript levels of BDNF and other candidate signaling molecules over time.  Our RT-qPCR work is done in collaboration with the Pleiss lab.

 

  • Immediate-early gene activation in response to odor learning across diverse regions of the brain.
  • RT-qPCR measurements of gene expression timecourses following learning (bdnf, c-Fos, Egr-1, etc.).
  • Induction of retrograde amnesia with isoflurane anesthesia, measuring the timecourse of anesthesia-resistant memory, and rescuing the amnestic effect within olfactory bulb.