Ikuko Smith

Research

My primary research goal is to elucidate the cellular and network mechanisms by which neural circuitry functions. During sensory perception, neural circuitry processes information by filtering, amplifying, and integrating electrical signals. My work focuses on uncovering the underpinnings of such processes using electrophysiology, two-photon imaging, intrinsic signal optical imaging and behavioral analyses.

One of my key interests is to understand the role of neuronal dendrites in processing information. Much like axons, dendrites are capable of firing electrical spikes. Such thresholded spiking allows dendrites to serve as transistors rather than passive cables and vastly increases the computational power of a single neuron. Whether such an active mechanism is engaged and plays a functional role in behaving animals, remains unclear.

In my lab, we employ direct patch clamp recordings from fine distal dendrites to examine their patterns of electrical activity during visual behavior. We seek to understand how dendrites contribute to synaptic computations and how their excitability is modified by the local microcircuitry in a state-dependent manner.

Selected Publications

Hira R., Townsend L.B., Smith I.T., Yu CH., Stirman J.N., Yu Y., Smith S.L. Mesoscale functional architecture in medial posterior parietal cortex. eLife. 2025 

Yu Y, Adsit LM, Smith IT. Comprehensive software suite for functional analysis and synaptic input mapping of dendritic spines imaged in vivo. Neurophotonics. 2024 

Yu CH, Yu Y, Adsit LM, Chang JT, Barchini J, Moberly AH, Benisty H, Kim J, Young BK, Heng K, Farinella DM, Leikvoll A, Pavan R, Vistein R, Nanfito BR, Hildebrand DGC, Otero-Coronel S, Vaziri A, Goldberg JL, Ricci AJ, Fitzpatrick D, Cardin JA, Higley MJ, Smith GB, Kara P, Nielsen KJ, Smith IT, Smith SL. The Cousa objective: a long-working distance air objective for multiphoton imaging in vivo. Nat Methods. 2024 

Dorsett C, Philpot BD, Smith SL, Smith IT. The Impact of SST and PV Interneurons on Nonlinear Synaptic Integration in the Neocortex. eNeuro. 2021 

Yu Y, Hira R, Stirman JN, Yu W, Smith IT, Smith SL. Mice use robust and common strategies to discriminate natural scenes. Sci Rep. 2018 

Smith IT, Townsend LB, Huh R, Zhu H, Smith SL. Stream-dependent development of higher visual cortical areas. Nat Neurosci. 2017 

Stirman JN, Smith IT, Kudenov MW, Smith SL. Wide field-of-view, multi-region, two-photon imaging of neuronal activity in the mammalian brain. Nat Biotechnol. 2016 

Smith SL, Smith IT, Branco T, Häusser M. Dendritic spikes enhance stimulus selectivity in cortical neurons in vivo. Nature. 2013