[Comp-neuro] New Paper on Anomalous diffusion in dendrites

Fidel Santamaria santamaria at neuro.duke.edu
Tue Dec 5 20:36:41 CET 2006


Dear colleagues,

I would like to bring to your attention our recent paper published in 
Neuron:

Anomalous Diffusion in Purkinje Cell Dendrites Caused by Spines, Neuron 
52:635-648
Fidel Santamaria, Stefan Wils, Erik De Schutter, and George J. Augustine

We combined local photolysis of caged compounds with fluorescence 
imaging to visualize molecular diffusion within dendrites of cerebellar 
Purkinje cells. Diffusion of a volume marker, fluorescein dextran, 
within spiny dendrites was remarkably slow in comparison to its 
diffusion in smooth dendrites. Computer simulations indicate that this 
retardation is due to a transient trapping of molecules within dendritic 
spines, yielding anomalous diffusion. We considered the influence of 
spine trapping on the diffusion of calcium ions (Ca2+) and 
inositol-1,4,5-triphospate (IP3), two synaptic second messengers. 
Diffusion of IP3 was strongly influenced by the presence of dendritic 
spines, while Ca2+ was removed so rapidly that it could not diffuse far 
enough to be trapped. We conclude that an important function of 
dendritic spines may be to trap chemical signals and thereby create 
slowed anomalous diffusion within dendrites.

Best regards,

-Fidel

-- 
Fidel Santamaria, PhD
Postdoctoral Researcher
Department of Neurobiology
Duke University Medical Center
P.O. Box 3209
Durham, NC 27710

Off: 919-681-6022
Lab: 919-681-6041
Fax: 919-681-9866
http://www.duke.edu/~fs01



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