Messages from Haruo Kasai
We have reported fascinating new properties of bran spine synapses in the end of the last year (Nature 600:686, 2021.11). We found the dendritic spine enlarges with a strength of muscle tension, and pushes the presynaptic terminal to promote exocytosis (PREST). This likely is a cellular basis of short-term and working-like memories, because PREST occurs rapidly, synapse specific, and lasting up to 20 min. We are now characterizing their molecular and cellular features so that we are able to identify the cognitive roles of PREST in various brain areas. Also, theoretical investigation of the role of rapid spine dynamics has been started in International Institute for Neurointelligence. Thus, we are studying both molecular and cognitive functions, and welcome new collaborators to join in our laboratory from all over the world. Feel free to contact us via e-mail.
We have found the presynaptic actions of spine enlargement of spines whose proof was technically demanding. Spine enlargement is destined to push the presynaptic terminals, but its proof has been extremely difficult. Using various recent technology, we have clarified the pushing effects are potent. It took 16 years after our discovery of spine enlargement. Fortunately we found unexpected features in the pushing, and it appears to me that he pushing effect is the most important discovery after mEPP (Fatt & Katz 1950). How its underlie the cognitive function?
We are improving the synaptic memory probes to elucidate spacio-temporal distributions of memory synapses.
Another niche is monoamine functions in the Nucleus accumbens (the ventral striatum) and PFC in emotional behaviors, lead by Sho Yaghishita.
We use new optogenetics, two-photon microscope, uncaging, electrophysiology, molecular biology, behavioral tasks to uncover the most mysterious aspect of brain functions, such as perception, learning & memory, emotion, and mental disorders (depression, schizophrenia, autism spectrum disorders). In achieving these, we have been based on the most prominent types of synapse, spine synapses, and we are heading for delineating the entire functional circuits underlying the brain functions and disorders. We welcome collaborators from abroad at various levels, master course and PhD students, post doctoral fellow and visiting professorships. If you are interested, do not hesitate to contact us with e-mail. (2020.04.22)