We have developed a collaborative web tool for computational biology by using open-source technologies. It allows the cooperative construction of computational models with NEURON. NEURON is a powerful local environment for modeling and simulating the nervous system. Our web tool facilitates researchers who are located far apart to build computational models of the brain, and share knowledge and opinions. The portal integrates all the necessary tools in just one. It allows the creation and participation in work sessions with NEURON, and synchronous and asynchronous file sharing. Moreover, it allows the analysis of the changes introduced in the models by the users, by means of a version control system, as well as real-time comments about each step in the development of each model. It only uses an Internet browser and minimum bandwidth consumption, thanks to the simplified data exchange process. In this paper, we present the tool NEURONSESSIONS, whose cooperative sessions also allow a virtual community to emerge for advancing in Neuroscience.