Simulation environment for computational models of neurons

 NEURON is a simulation environment for modeling individual neurons and networks
 of neurons. It provides tools for conveniently building, managing, and using
 models in a way that is numerically sound and computationally efficient. It is
 particularly well-suited to problems that are closely linked to experimental
 data, especially those that involve cells with complex anatomical and
 biophysical properties.
 .
 NEURON offers
  * "natural syntax", which allows one to specify model properties in
    familiar idioms
  * efficient and painless spatial and temporal discretization
  * several different, user-selectable numerical integration methods
  * convenient user interface (interpreters + GUI)
  * user-extendable library of biophysical mechanisms