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. The mechanisms that establish fine-scale networks in the visual cortex and the role of these networks in visual information processing
2. Cell-lineage dependent establishment of neuronal connections and visual responsiveness
3. 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
4. Morphological analysis of neural circuits using trans-synaptic virus tracers
5. Developmental mechanisms of visual responsiveness, plasticity, and synaptic connections in each neuron subtypes
We are also conducting collaborative research and looking for graduate students interested in the developmental mechanisms of brain functions.
Figure Electriphysiological and morphological analyses of cortical neural circuits
A. Cross-correlation analysis of photostimulation-evoked excitatory postsynaptic currents (EPSCs) simultaneously recorded from a pair of layer 2/3 pyramidal neurons that were synaptically connected.
B. Visualized neurons after analysis of synaptic connections. Several recorded neurons stained by biocytin in the primary visual cortex(yellow).
Selected publications
*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)*Nishio N, Hayashi K, Ishikawa AW, and Yoshimura Y (2021) The role of early visual experience in the development of spatial-frequency preference in the primary visual cortex. J Physiol. 599（17）4131-4152.