What is the most complex artificial neural network created to date? A few years ago I wrote a research paper for college on neural networks.  At the time IBM's Blue Brain was the clear winner. Some rumor went around that they were close to emulating a brain the complexity of a cat; this has since been debunked. 

At the time their research was groundbreaking and previously even emulating the brain of a C. Elegans seemed far-fetched.

Describing the complexity of neural networks is complex but I'll define number of synapses or neurons as an easily measurable scale of complexity.

What is the most complex working artificial neural network? What is the relative complexity of this network compared to an animal's brain?
A (probably incomplete) list of ongoing whole brain simulation projects can be found at http://www.artificialbrains.com/. However, based on the information reported on this site, it is sometimes hard do distinguish what already has been achieved and what is still in the planning stage. Nevertheless it gives a good overview to start with.