Acute stress induces negative emotional states such as anxiety and triggers normal adaptive behaviors to ensure safety and security. However, excessive and prolonged stress impairs appropriate responses, leading to psychiatric disorders such as anxiety disorders and depression. The neural mechanisms underlying stress responses require communication across the entire brain, including the cerebral cortex, subcortical regions, and upper brainstem areas. However, the fundamental pathways and mechanisms supporting stress response processing are not yet fully understood.
Recently, we identified that the claustrum plays a crucial role in the neural circuits responsible for generating anxiety responses to stress. This project aims to explore the connection between the claustrum and stress-related psychiatric disorders, such as stress-induced insomnia and panic disorder. While the claustrum is believed to be involved in brain functions like consciousness and attention, its specific roles remain unclear. Therefore, we also investigating its functions related to vigilance and the processing of unconscious information.

In our social lives, emotions like envy and feelings of unfairness often stem from differences between ourselves and others, such as gender, race, and social status. The ability to recognize these differences is a fundamental brain function that forms the basis of our mind, and its disruption can be linked to psychiatric disorders. Social emotions like envy and inequity aversion were once thought to be exclusive to humans and some primates. However, these emotions involve complex brain activities that very over time and space, and the detailed mechanisms have not been thoroughly explored using experimental animals like rodents, which are ideal for neuroscientific studies.
Recent research has shown that rodents can also experience reactions based on comparisons self-other comparisons, leading to a sense of unfairness. This project aims to create a unique behavioral evaluation system using rodents and integrate advanced imaging technologies to uncover the neural mechanisms behind feelings of inequity.

Mechanisms of behavioral change under unfair conditions using rodents

Autism Spectrum Disorder (ASD) is a neurodevelopmental condition marked by difficulties in social communication and repetitive behaviors. It is believed that epigenetic changes during the development of the cerebral cortex may disrupt the formation and maintenance of neural networks, contributing to ASD. Recent research indicates that epigenetic changes occurring at specific stages of fetal development can affect the normal structure and connectivity of the cerebral cortex, potentially leading to difficulties in processing external information later in life. However, the detailed mechanisms involved are still not fully understood.
This project aims to investigate these mechanisms by using fate mapping in ASD model mice, which are influenced by genetic and environmental factors. By labeling neurons that differentiate at specific developmental stages, we seek to pinpoint the precise molecular changes occurring in various regions of the brain.

The brain's complex neural networks enable a wide range of functions through both localized (micro) and widespread (macro) information processing. Understanding the brain functions requires capturing all neural activities over time and integrating this data comprehensively. While current technologies make this challenging, alternative methods like fMRI and large-scale imaging techniques have been developed to study brain functions. Recently, we have developed a high-resolution, fast whole-brain imaging system (named FAST) that can visualize the entire brain at the cellular level. Using reporter mice that express immediate early genes such as fos and arc, which indicate neural activation, we have been able to track activation changes across the brain in response to various external stimuli. By applying advanced data analysis techniques, we can identify changes in functional networks and pinpoint crucial brain regions without preconceived hypotheses.
In this project, we are exploring brain activation changes in model animals in response to various external stimuli, such as drug administration, using these innovative techniques.