Hi there,
I think the quickest way to get what you want is to use activity generators:
http://simbrain.net/Documentation/docs/Pages/Network/activityGenerator.htmlTo create an activity generator go the network > insert menu and select activity generator. We don't have possoin but there are other distributions you can mess with. There is a logistic map which is a simple iterated function. And of course, you can make little circuits which are also basically iterated functions and send their outputs to another neuron.
Best,
- Jeff