Shigenobu Toda, Ph.D.

Assistant Professor of Psychiatry and Neurobiology

Contact Information:

13-1 Takara-machi, Kanazawa,
Ishikawa, Japan, 920-8641
tel:81-76-265-2308
fax:81-76-234-4254
todas@med.kanazawa-u.ac.jp

Education:

Kanazawa University Graduate School of Medicine

Project Description:

Effect of Actin Cycling on Spine Morphology in Neucleus Accumbens of Cocaine-treated Rats.

Based on previous findings about enhanced actin cycling in the accumbens of rats repeatedly injected with cocaine (Toda et al, 2006), the hypothesis was advanced that cocaine induced-kinetics of the major PSD proteins as well as spine morphology might be affected in an actin cycling-dependent manner. To address these possibilities, a time-course dependent, PSD protein profiling using subcellular fractionation was employed. In control animals, most of the PSD proteins reached a peak in the PSD fraction between 2 and 6 hrs after a cocaine challenge. Meanwhile, in chronic cocaine-treated rats, the peak was observed 2 hrs after cocaine challenge, and PSD proteins were eliminated from the PSD fraction at 6 hrs.  These data suggest that the kinetics of the entire PSD induced by cocaine challenge are enhanced in chronic cocaine-treated rats, probably due to augmented actin cycling.

Publications Arising from Pilot Project:

Toda, S., H-W Shen, S Cagle and PW Kalivas.  2006.  Regulation of actin binding proteins contributes to cocaine-induced behavioral plasticity. J Neuroscience, 26: 1579-1587.
S. Toda and P. W. Kalivas. Research in addiction as chronic and progressive mental disorder involving metaplasticity (in Japanese). Cell Technology, 26 (1), 52-56, 2007, Shujyunsya, Tokyo
Shen H, S Sesack, S Toda and PW Kalivas.  2008.  Automated quantification of dendritic spine density and spine head diameter in medium spiny neurons. Br Struct Func, in press.
Toda S, H Shen, K Moussawi, A Bouknight and PW Kalivas.  2008.  Cocaine-induced metaplasticity in dendritic spines.  Science, in review

Funding Arising from Pilot Project:

5 RO1 DA012513  Project 1: Neurobiology of Addiction Research Center
PI:  Peter Kalivas, Ph.D.;  Co-PI:  Shigenobu Toda, Ph.D.
Proposed funding period:  05/2008-04/2013
RO1 to NIDA, June, 2007
PI:  Shigenobu Toda, Ph.D.