bill wrote:I'm new to NEURON, and I wanted to know if it has built-in tools for changing temperature, establishing a random network connectivity using a random number generator
Good questions. The answers are variants of "everything is possible with programming."
The hoc keyword celsius is reserved to mean temperature.
Go here
http://www.neuron.yale.edu/neuron/docs
and explore the Programmer's Reference to read about it. If a model specification includes
an ionic accumulation mechanism, celsius will affect that ion's equilibrium potential. If a
biophysical mechanism (e.g. an ionic conductance) involves rate constants that are
calculated from formulas that explicitly involve celsius, that mechanism will be
temperature-sensitive. Otherwise, celsius will have no effect.
Network archtecture is completely up to the user--if you want a particular architecture,
you write the code for it. Chapter 11 of the NEURON book shows how to use the
Network Builder (a GUI tool) to set up a toy prototype net, and then mine reusable
code from it in order to construct a large network algorithmically. NEURON's random
number generators are documented in the Programmers' Reference. With a few lines
of code it is very easy to set up random connectivity.
and simulating extracellular stimulation of networks of neurons
First a comment: if you want a _mechanistic_ model of extracellular stimulation,
Maxwell's equations require your model cells to have multiple compartments. If a
functional model will suffice, single compartment cells can be used (just inject a
current into them).
The extracellular mechanism, which can be used to implement mechanistic models of
extracellular stimulation and/or recording, is described in the Programmer's Reference.
Here is a "biophysically correct" example of its use
https://www.neuron.yale.edu/phpBB2/viewtopic.php?t=168
that can be generalized for stimulation of multiple cells.