RESEARCH

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder with age-inappropriate inattention (easy to distract, easy to make careless mistakes) and hyperactivity/impulsivity (restlessness, poor patience). Autism spectrum disorder (ASD) is a neurodevelopmental disorder with social communication problems, limited, repetitive behavior, and interest as main symptoms. There is a close relationship between these neurodevelopmental disorders and trauma, and while children with neurodevelopmental disorders are at increased risk of abuse, which is one of the most common forms of trauma, abuse-induced attachment disorder (RAD) sometimes resemble neurodevelopmental disorders. In addition, ADHD, ASD, and RAD are all known to have a high risk of developing psychiatric disorders such as depression and anxiety as secondary disorders. Therefore, early diagnosis and early intervention, and elucidation of the pathological mechanism are important issues.

Focusing especially on structural and functional MRI studies of the human brain, we will elucidate brain mechanisms mainly in ADHD, ASD, and RAD, and also will look for biomarkers that can be useful in clinical settings. In order to carry out the above-mentioned research, advanced knowledge and skills are required in a wide range of fields such as developmental pediatrics, child and adolescent psychiatry, radiology, psychology, neuroscience, informatics, and pedagogy. Therefore, we are actively promoting collaboration with researchers from various fields and backgrounds. Additionally, we utilize databases such as ABCD (Adolescent Brain Cognitive Development) study, a large-scale longitudinal study in the United States which collects brain images, genes, and behavior data of about 12,000 children. We will also construct an original data base by multi-institutional collaborative research based on United Graduate School of Child Development, and pursue reproducible results even in independent sample groups.

We are performing a series of researches to clarify the molecular and cellular mechanisms underlying brain development and functions. By elucidating such mechanisms, we can dissect the etiological mechanisms of neurodevelopmental disorders as perturbed processes of typical brain development and/or as disordered states of normal brain functions, which can lead to deeper understanding of causes and symptoms of neurodevelopmental disorders and development of the methods for preventive and therapeutic interventions of neurodevelopmental disorders. In our research field, the following projects are currently ongoing.

1. Exploring the biological markers useful for the diagnosis of autism. We are exploring the changes in internal molecular states which are observed specifically in autistic patients in details by analyses on the blood samples and the hair samples donated by autistic patients and children with typical development.
2. Development of methods for preventive and therapeutic interventions of autism by making use of model animals. We are examining whether the observations in autistic patients in project. 1) can be good clinical targets by using autistic model animals. Currently, we are focusing on the abnormal metabolic states of blood lipids and the abnormal states of serotonergic systems in brain, both of which have been observed specifically in autistic patients in our previous clinical studies.
3. Elucidation of the effects of environmental factors on brain development and the underlying mechanisms. Focusing on the brain development based on the relationships between mother and children (fetuses), we are working on functions and mechanisms of functions at molecular, cellular and behavioral levels of various environmental factors during perinatal periods, including poor nutritional condition, quantity and quality of gut microbiota of mothers and infants, medication which mothers are possibly subject to during perinatal periods, with aims to develop methods for preventive and therapeutic interventions and diagnoses of neurodevelopmental disorders.