Genetically engineered animal models of marmosets are extremely useful for elucidating human diseases and developing treatments, but their creation requires many embryos. To develop a new method for producing embryos, the research group implanted marmoset ovaries under the kidney capsule of mice, harvested eggs matured by hormone administration, successfully fertilized them to produce embryos and obtained blastocysts. This is the first time in the world that a primate embryo capable of implantation in the uterus has been obtained through xenotransplantation.

The research group revealed that propagation of prediction error signals from higher-order auditory cortex to primary auditory cortex is critical for the change detection in the non-human primates. The feedback error signal is critical for automatic detection of unpredicted stimuli in physiological auditory processing and may serve as backpropagation-like learning.

The research group demonstrated 2P-SRRF, a fluorescence spatiotemporal correlation analysis-based two-photon super-resolution microscopy. Application of 2P-SRRF enabled in-vivo visualization of tiny neuronal structures located at a depth of several hundred micrometers. This technique will contribute to uncovering various nanoscale biological phenomena occurring in the deep area of organisms.

We conducted an adolescent cohort study and found that changes in psychological difficulties from 13 to 16 years old were associated with changes in the electrophysiological index of glutamatergic neurotransmission. The results would be useful for understanding the mechanism of mental illness and contribute to the promotion of mental health in adolescence.

The research group developed a novel super-resolution two-photon excitation (2PE) microscope with all-synchronized picosecond pulse light sources and time-gated fluorescence detection, namely, all-pulsed 2PE-gSTED microscopy. This microscopy will facilitate deeper super-resolution imaging of the biological phenomena at the nanoscale in brain tissue.

The research team has succeeded in detecting the brain neuronal networks involved in trauma memory, using a novel method that combines optics and machine learning, capturing the complex changes that occur during memory formation and uncovering the mechanisms by which trauma memories are created.

The research group found a common structural footprint, a hypertrophy of the striatal medium spiny neuron (MSN) terminals, in L-DOPA-induced dyskinesia and antipsychotics-induced tardive dyskinesia. Reduced D2R signaling with repetitive dopamine fluctuations leads to VGAT overexpression in striatal MSNs, resulting in the shared structural modeling and late-onset dyskinesia formation.