# Instructions for incorporating the "isynchan" object into GENESIS

The GENESIS synchan object (documented in the GENESIS Reference Manual) implements a dual-exponential model of synaptic conductance, with two time constants tau1 and tau2. The isynchan is a modification to synchan that provides an instantaneous rise to a conductance gmax, followed by an exponential decay with time constant tau1. The fields and usage are the same as for the synchan, but the value of the tau2 field is ignored.

This directory (isynchan) contains the top level Makefile (derived from Usermake), and the library directory isynlib, which contains the source code for the isynchan object and the library Makefile (derived from Libmake). It may also contain a precompiled executable "igenesis" that was compiled under Fedora Core 5 Linux on a x386 (Pentium) with gcc 4.1.0. This may run under your Linux installation. If not, or you are using a different OS or hardware platform, follow the instructions below to compile a version of GENESIS that includes the isynchan objecct. In either case, you must have first installed GENESIS.

The top level Makefile in the isynchan directory will need to be edited in order to provide the definitions (MACHINE, OS, etc.) for your GENESIS installation, and INSTALLDIR (GENINST in older versions of GENESIS) should be set to the place where GENESIS is installed. The provided isynlib/Makefile should not require further editing.

The documentation in the GENESIS Reference Manual on "Customizing GENESIS" gives further details of compiling these, and similar user-contributed libraries, into GENESIS. Note that these files should NOT be installed in the genesis/src directory.

Once the Makefile has been properly edited, it should be possible to type "make" in order to create a new genesis executable "igenesis" that incorporates the new isynchan object.