How is it that smells can evoke such strong emotional memories? For many people, an unexpected whiff of a familiar scent transports the mind to memories of a cherished event, place or person. For others, odor-triggered recall can evoke traumatizing memories. My lab studies the neural circuits and mechanisms that underlie the encoding of olfactory information in the cortex. The overarching goal of my research is to understand how stable sensory representations and memories are formed, maintained, and conversely, how they are retrained or diminished when no longer useful or pathological.
Most of my research has been driven by the quest to understand the relationship between synaptic dynamics and spike activity. Currently, we are investigating the role of inhibition in regulating the spatial profiles of neural activity as well as gating long-term synaptic plasticity and ensemble formation during odor guided behavior. While many of the interneuron classes in piriform cortex have been identified, the specific roles interneuron types play in odor related activity and learning are unknown. Moreover, despite their popularity in other sensory cortices, the inhibitory circuits that regulate inhibition and potentially disinhibit pyramidal cells have not been identified in olfactory cortex. We capitalize on a variety of genetic tools, namely optogenetics, chemogenetics and TRAP (targeted recombination in active populations), which allow a detailed dissection of neural circuits and analysis of synaptic properties following odor-guided behavior. Our aim is to determine the microcircuit motifs that underlie sensory representation in the brain.
AM Large, NW Vogler, M Canto-Bustos, FK Friason, P Schick and AM Oswald (2018) Differential inhibition of pyramidal cells and inhibitory interneurons along the rostrocaudal axis of anterior piriform cortex Proc Natl Acad Sci U S A. 115 (34) E8067-E8076
AM Large, NW Vogler, MB Canto, P Schick, AM Oswald (2017) Opposing spatial gradients of inhibition and neural activity in mouse olfactory cortex. bioRxiv doi: https://doi.org/10.1101/152975
AM Large, NA Kunz, SL Mielo, AM Oswald (2016) Inhibition by somatostatin interneurons in olfactory cortex. Front. Neural Circuits | doi: 10.3389/fncir.2016.00062
AM Large, NW Vogler, S Mielo, AM Oswald (2016) Balanced feedforward inhibition and dominant recurrent inhibition in olfactory cortex. Proc Natl Acad Sci U S A. 113(8):2276-81.
Oswald, A.M., and Urban, N.N. Interactions between behaviorally relevant rhythms and synaptic plasticity alter coding in the piriform cortex. J. Neuroscience. 32: 6092-6104, 2012.
Kumar, A.L., Oswald, A.M., Urban, N.N., and Doiron, B. Shaping neural correlation through balanced synaptic inputs. PLoS Computational Biology. 7(12):e1002305, 2011.