Research

Division of Visual Information Processing

Member

Analysis of mechanisms underlying information processing and activity-dependent functional developments in the neocortex

 Sensory experience during postnatal development is required for the maturation and refinement of neuronal circuits in the sensory cortex. This leads to the development of cortical functions suitable for the living environment. To elucidate the mechanisms underlying information processing in the sensory cortex and the experience-dependent regulation of that processing, we are studying the relationship between visual functions and the signaling properties of neural circuits using rat and mouse visual cortex. To this end, we are analyzing the visual responses of cortical neurons using multi-channel electrodes or calcium imaging with 2-photon microscopy. Also, we are studying neural circuit properties with a combination of laser scanning photostimulation and whole-cell patch-clamp recording methods in slice preparations; and neural connections morphologically using modern virus tracers. The following is a list of our main projects currently ongoing.

1. Synaptic plasticity and visual response plasticity in animals at different developmental stages and in animals subjected to the manipulation of visual experience during postnatal development
2. Developmental mechanisms of visual responsiveness, plasticity, and synaptic connections in each neuron subtypes
3.  Cell-lineage dependent establishment of neuronal connections and visual responsiveness
We are also conducting collaborative research and looking for graduate students interested in the developmental mechanisms of brain functions.

Figure  Analysis of visual response plasticity based on cortical neuron subtypes

(A) Visual responses were recorded from layer 6b of the primary visual cortex of living mice with two-photon imaging, followed by tissue clearing.
(B) Layer 6b neurons from in vivo two-photon imaging (left) and the same areas from a cleared brain (right).
(C) Most of the recorded L6b neurons expressed CTGF which is a subplate neuron marker. Foxp2 is a marker of cortico-thalamic neurons.
(D) An example of a volumetric image of cleared brain.

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Selected publications

*Yoneda T, Hayashi K, Yoshimura Y (2023) Experience-dependent functional plasticity and visual response selectivity of surviving subplate neurons in the mouse visual cortex. PNAS. 120(9):e2217011120
*Kimura R, Yoshimura Y (2021) The contribution of low contrast–preferring neurons to information representation in the primary visual cortex after learning. Science Adv. 7 (48)