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This Article Full Text Full Text (PDF) All Versions of this Article: 567/3/1057    most recent jphysiol.2005.092882v1 Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Veredas, F. J Articles by Alonso, J.-M. Search for Related Content PubMed PubMed Citation Articles by Veredas, F. J Articles by Alonso, J.-M.

¹ Departamento de Lenguajes y Ciencias de la Computación, Universidad de Málaga, Málaga, Spain
² Department of Psychology, University of Connecticut, Storrs, CT, USA
³ SUNY State College of Optometry, New York, NY, USA

Across the visual pathway, strong monosynaptic connections generate a precise correlated firing between presynaptic and postsynaptic neurons. The precision of this correlated firing is not the same within thalamus and visual cortex. While retinogeniculate connections generate a very narrow peak in the correlogram (peak width < 1 ms), the peaks generated by geniculocortical and corticocortical connections have usually a time course of several milliseconds. Several factors could explain these differences in timing precision such as the amplitude of the monosynaptic EPSP (excitatory postsynaptic potential), its time course or the contribution of polysynaptic inputs. While it is difficult to isolate the contribution of each factor in physiological experiments, a first approximation can be done in modelling studies. Here, we simulated two monosynaptically connected neurons to measure changes in their correlated firing as we independently modified different parameters of the connection. Our results suggest that the precision of the correlated firing generated by strong monosynaptic connections is mostly determined by the EPSP time course of the connection and much less by other factors. In addition, we show that a polysynaptic pathway is unlikely to emulate the correlated firing generated by a monosynaptic connection unless it generates EPSPs with very small latency jitter.

(Received 16 June 2005; accepted after revision 7 July 2005; first published online 14 July 2005)
Corresponding author J.-M. Alonso: Department of Biological Sciences, SUNY (College of Optometry), 33 West 42nd Street, New York, NY 10036, USA. Email: jalonso{at}mail.sunyopt.edu