This is the readme for the model files associated with the paper: Larkum ME, Nevian T, Sandler M, Polsky A, Schiller J (2009) Synaptic integration in tuft dendrites of layer 5 pyramidal neurons: a new unifying principle. Science 325:756-60 These NEURON model files were supplied by Alon Polsky. Usage: to run the model either auto-launch from ModelDB or download and extract this archive and then compile the mod files under mswin: run mknrndll and select this folder to create the nrnmech.dll linux: run nrnivmodl in this folder mac os x: drag and drop this folder onto mknrndll then to start the simulation under mswin: double click the mosinit.hoc file using windows explorer linux: type "nrngui mosinit.hoc" in the shell prompt in this folder mac os x: drag and drop the mosinit.hoc file onto the nrngui icon Once the simulation is running: To run the current injection simulations run the model adjust the proximal or the distal IClamp processes � 0.5nA works OK for the distal and 0.9nA for the proximal processes. To examine the effects of NMDA spike initiation increase the gmax variable of the �glutamate� point process. Other variables used in �glutamate� are: e-the reversal potential (should be 0) ntar � NMDA to AMPA ratio (in this point process gmax is the NMDA conductance, and the AMPA conductance is calculated based on the ntar value. So, for example, at gmax of 1nS and ntar of 10, the NMDA conductance would be 1nS and AMPA 0.1nS) del-onset time of the first synaptic input Tspike � ISI presynaptic activations (for presynaptic input train) in ms. Nspike-number of presynaptic activations (for presynaptic input train). For example, presynaptic train of 5 inputs at 100Hz can be activated with Tspike=5 Nspike=10. Summation of different distribution of synapses can be examined with the �Control� panel. numS variable is the number of synapses GmaxS is the conductance of a single synapse (similar to gmax of �glutamate� process Synapses can be distributed based on distance from the main bifurcation (between SubTuftProxS and SubTuftDistS values; only when generation is 0) or dendrite generation. Synapses can have either AMPA and NMDA components when the (NMDA=1; AMPA=2) value is 1 or AMPA only when the (NMDA=1; AMPA=2) value is 2. Please note that in some cases the temperature and the GlobalRa variables are not automatically set to the right values. Best simulation time value is 200ms. --- When the simulation starts it displays a default location of synapses:and pressing "Init & Run" will produce the simulations default display:
Detailed instructions on generating panels from supplementary Fig. S2: Here are the instructions for how to create simulations similar as to presented at fig. S2: For a simulation of NMDA spike (panel C) set the 'global Ra' to any value between 80 to 90ohm-cm and press 'run'. The glutamatergic synapse is located at the appropriate location and should generate 3 impulses with NMDA spike following the second impulse. Setting global Ra to 85 ohm-cm produced this graph:
For a simulation of synaptic summation (panels G and H) fist set the gmax value of the glutamatergic synapse (point process glutamate[200]) to zero. Then redistribute 100 synapses over the 3rd order branches by setting the 'generation' value in the 'Control' panel to 3. Set the numS to 100 (number of synapses) and GmaxS to 1 (conductance of each synapse in nS). Hit 'run' to generate a plot similar to panel G:
In order to examine what is the effect of AMPA only synapses, change the value of 'NMDA=1 AMPA=2' field in 'control' panel to 2. Hit 'run' to generate the left part of plot H:
In order to increase the number of synapses set the 'numS' value to a higher number (500 will produce a similar result as to presented at plot H, right part):
As the synapses are distributed randomly, each run's result is unique, and may be somewhat different from the simulation presented in the paper. 20120326 the solve method was updated from euler to derivimplicit in cad2.mod. See http://www.neuron.yale.edu/phpBB/viewtopic.php?f=28&t=592