Toyo University

Laboratory for Molecular Neurobiology

Research Aim

Synaptic plasticity underlies learning and memory 

The neurons in the brain are connected with each other at synapses to form neural circuits. It is known that, unlike electronic circuits, neural circuits are flexible and can be modified by various experiences and environments. This flexibility is known as "synaptic plasticity".

Although it has been well studied in the field of neuroscience, the mechanism of synaptic plasticity is still largely unknown. We believe that elucidation of the mechanism of synaptic plasticity will lead not only to a better understanding of the fundamental principles of brain functions, but also to the understanding of various neuropsychiatric diseases, likely allowing for the development of new therapeutic methods.


Message

Nobuhiko Kojima, Professor 


How is the mind created, where and how does the mind exist?

It is now well accepted that the mind is created in the brain, not in the heart. Like any other organs, the brain is composed of cells and molecules. Genes, the blueprints of life, generate molecules that govern the synaptic connection among neurons and create complex neural networks. Thus, the synapses, as a place of information processing, are critical for creating the mind.

A large number of molecules accumulate at the synapse and support synaptic functions. However, the molecular mechanism underlying synaptic functions is not fully understood yet. Unlike electronic circuits, neural circuits can be added, lost or changed through various experiences. This unique feature of the brain, known as "plasticity," enables learning and memory. However, disturbance in the plasticity may cause various psychiatric disorders.

We aim to clarify the molecular mechanism of synaptic plasticity, which can be considered as a neural basis of the mind, by investigating the synaptic functions at a molecular, cellular, and behavioral levels.

For applicants

Different from electrical circuits, the synaptic connections in the brain are variable and are the fundamentals of the plastic structure of the brain. Although synaptic plasticity is a well-established phenomenon, the underlying molecular mechanisms remain largely unknown. However, there is considerable scope for further research. Hence, for those who wish to join us, we would like you to explore these mechanisms with a creative and challenging spirit that is not bound by existing concepts.


Research Themes

1. The function of actin cytoskeletal protein in dendritic spines

The dendritic spines is known as major postsynaptic sites, and the shape of dendritic spine is supported by actin cytoskeleton. We focus on drebrin, a spine-resident side-binding protein of F-actin, which is thought to be involved in learning and memory as well as in cognitive impairment caused by Alzheimer's disease. We have studied the functional role of drebrin in dendritic spines, and have also explored novel binding partners of drebrin.


     2. Synaptic abnormalities in animal models of neuropsychiatric disorders

   We have studied the relationship between behavioral abnormalities and the morphology/function of

 brain synapses, using animal models of stress-induced neuropsychiatric disorders (e.g., human

 depression and post traumatic stress disorder) or developmental disorders such as autism spectrum

 disorder.










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