We analyze the conditions to build the fan-out stage of sensory systems. The fan-out stage needs to be properly built for posterior processing. In olfaction, the type of computation to analyze is the discrimination and association of odors. The following papers deal with these fascinating issues, a few more are in the making,

• Marta Garcia-Sanchez and R. Huerta. Design parameters of the Fan-out phase of Sensory Systems. Journal of Computational Neuroscience 15:5-17 (2003). It can be proved that the injectivity measure is an upper bound (see the Appendix of this version of the paper)
• Huerta, Nowotny, Garcia-Sanchez, Abarbanel, Rabinovich, Learning Classification in the olfactory system of insects. Neural Computation to appear in August 2004.