GENESIS implementation by D. Beeman, January 1998.
The passive cell model parameter files layer5.p and layer2.p describe
the reduced neocortical pyramidal cell models of Bush and Sejnowski (1993).
These are simplified (8-9 compartment) models of much larger (about
400 compartment) models of pyramidal cells from area 17 of cat visual
cortex (Koch, Douglas and Wehmeier 1990; Bernander, Douglas, Martin
and Koch 1991). A collapsing method was used that conserves the axial
resistance and makes some adjustments in the passive membrane
parameters in order to faithfully reproduce the electrical responses
of the larger models.
layer5.p has 9 compartments and represents a layer 5 pyramidal cell.
layer2.p has 8 compartments and represents the more compact layer 2/3
spiny stellate cell (modified superficial pyramidal cell).
The reduced Bernander model
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The files layer5BDK.p and layer2BDK.p use the layer5.p and layer2.p
morphologies to implement smaller versions of the Bernander et al.
(1991) models. These use active channel model descriptions taken from
Bernander, Douglas and Koch (1992). With these channels, the firing
patterns under current clamp are very close to those of the larger
models, with the spike adaptation typical of regular-firing pyramidal
cells. Slightly different sets of channels have been used with these
reduced morphologies by Bush and Sejnowski (1996) to model cortical
networks.
The channels are defined and described in the file BDKchan.g.
A userprefs.g file is included for use with Neurokit.
References:
O. Bernander, R. J. Douglas, K. A. C. Martin and C. Koch, Synaptic
background activity influences spatiotemporal integration in single
pyramidal cells, Proc. Natl. Acad. Sci. 88:11569-11573 (1991).
O. Bernander, R. J. Douglas and C. Koch, A model of regular-firing
cortical pyramidal neurons, CNS Memo 16, Caltech (1992).
P. C. Bush and T. J. Sejnowski, Reduced compartmental models of
neocortical pyramidal cells, J. Neurosci. Methods 46:159-166 (1993).
P. C. Bush and T. J. Sejnowski, Inhibition synchronizes sparsely
connected cortical neurons within and between columns in realistic
network models, J. Comput. Neurosci. 3:91-110 (1996).
C. Koch, R. J. Douglas and U. Wehmeier, Visibility of synaptically
induced conductance changes: theory and simulations of anatomically
characterized cortical pyramidal cells, J. Neurosci. 10:1728-1744.