Section: Research

Motojiro Yoshihara, Ph.D.

Academic Role: Assistant Professor

Faculty Appointment(s) In:
   Neurobiology

Other Affiliation(s):
   Program in Neuroscience

Synaptic physiology and memory

My lab is trying to ask a fundamental question “How do we remember?” by studying synaptic physiology in the fruit fly, Drosophila.  I believe that memory is stored as a series of neurons connected through strengthened synapses, in which sequential firing of the neurons allows recall of specific events. Therefore, understanding mechanisms of synaptic modification is a key to understanding mechanisms underlying  memory.  Taking advantage of a combination of synaptic physiological methods and sophisticated Drosophila genetics, we have recently proposed a novel hypothesis, “local feedback model” as a potential molecular and cellular basis of memory formation (Yoshihara et al., 2005, Science 310: 858-863).  In this model, I postulate that mutual intensification between presynaptic and postsynaptic cells by a positive feedback loop at single synapses keeps individual synapses potentiated, leading to eventual morphological change and perpetually strengthened synapses, storing memory.

In my lab, we are testing this working hypothesis to answer the question “how do we remember?”, by electrophysiology (whole cell patch clamping, two electrode voltage clamping, current clamping), live imaging and live manipulations (Ca²⁺ imaging, Ca²⁺ uncaging etc.), confocal microscopy, electron microscopy, combined with fly genetics.  In addition to the plasticity projects, we are also studying mechanism of synaptic transmission in Drosophila.

Office: 705
Phone: 508-856-6691
E-mail: Motojiro.Yoshihara@umassmed.edu
Keywords: Neurobiology, Synapses, Electrophysiology, Neural Plasticity, Organisms - Drosophila

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