The impact of thalamo-cortical projections on activity spread in cortex

To what extent does thalamo-cortical connectivity in/uence global patterns of macroscopical activity spread in cat cortex? We address this question by simulation of activity /ow in a network model representing cortical areas and thalamic nuclei as nodes with all or none activity. The connectivity schemes employed are based on data from anatomical tracer studies. For two networks, with and without thalamic nuclei, we investigate how well physiological experiments from strychnine neuronography can be reproduced. Our results indicate that thalamic interaction does in/uence cortical activity spread. However, while the relation between physiological activity spread and anatomy of the cortico–cortical connectivity is signi5cant, the relation between activity spread and the anatomy of cortico–thalamic connections is not. c © 2003 Elsevier Science B.V. All rights reserved.