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From: Fidel Santamaria (santamaria@neuro.duke.edu)
Date: Mon Oct 07 2002 - 17:53:58 CEST

Dear colleagues,

We have recently published a paper on dendritic synaptic integration using
a detailed model of a Purkinje cell.
Modulatory effects of parallel fiber and molecular layer interneuron
synaptic activity on purkinje cell responses to ascending segment input: a
modeling study.
J Comput Neurosci. 2002 Nov-Dec;13(3):217-35.
PMID: 12226562 [PubMed - in process]
Santamaria F, Jaeger D, De Schutter E, Bower JM.

Division of Biology, California Institute of Technology, 216-76, Pasadena,
CA 91125, USA. fidel@bbb.caltech.edu; santamaria@neuro.duke.edu

Based on anatomical, physiological, and model-based studies, it has been
proposed that synapses associated with the ascending segment of granule
cell axons provide the principle excitatory drive on Purkinje cells which
is then modulated by the more numerous parallel fiber synapses. In this
study we have evaluated this idea using a detailed compartmental model of a
cerebellar Purkinje cell by providing identical ascending segment synaptic
inputs during different levels of random parallel fiber and molecular
interneuron input. Results suggest that background inputs from parallel
fibers and molecular layer interneurons can have a substantial effect on
the response of Purkinje cells to ascending segment inputs. Interestingly,
these effects are not reflected in the average firing rate of the Purkinje
cell and are thus entirely dendritic in effect. These results are
considered in the context of the known segregated spatial distribution of
the parallel fibers and ascending segment synapses and a new hypothesis
concerning the functional organization of cerebellar cortical circuitry.

Best regards,

-Fidel

------------------------------------------------
Fidel Santamaria, Ph. D.
Postdoctoral Research Associate
Department of Neurobiology
Duke University Medical Center
P.O. Box 3209
Durham, NC 27710

Off: 919-681-6165
Fax: 919-681-9866
http://www.duke.edu/~fs01