PROJECT SUMMARY/ABSTRACT
The olfactory system is critical to several aspects of behavior and survival in mammals, including humans. The
olfactory bulb is the first processing station of the olfactory system and constitutes an exceptional model system
for the study of neural coding, capable of encoding a highly complex sensory space within a compact and well-
organized structure. Understanding local circuit computation within the olfactory bulb will thus provide key insight
into fundamental principles of brain function. Broad perturbation of synaptic inhibition within the olfactory bulb
significantly disrupts projection mitral/tufted cell synchronization and olfactory-guided behavior, underscoring a
central role of inhibitory interneurons in local circuit computation. In contrast to other regions of the brain such
as neocortex and hippocampus, however, fundamental understanding of how the diverse inhibitory interneurons
within the olfactory bulb specifically support neural coding has remained elusive, with detailed knowledge of how
unitary synaptic interactions contribute to the precise regulation of mitral/tufted cell spike timing in particular
lacking. To advance understanding of local circuit computation and neural coding in the olfactory bulb, this project
will therefore directly examine unitary synaptic interactions between mitral/tufted cells and a highly-conserved
but understudied class of fast-spiking interneurons, using whole-cell pair recordings in acute mouse brain slices
together with pharmacology, morphological reconstruction, immunostaining, and simulations. Investigation will
specifically address three aims: 1) determine how fast-spiking interneurons regulate mitral/tufted cell spike
timing, 2) determine how dendritic computation supports fast-spiking interneuron function, and 3) determine how
fast-spiking interneuron signaling adapts with neural activity.