Some remarks about file names and contained data:
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Files ff*_soma, fb*_soma and pyr*_soma contain the somatic membrane
potential of the respective simulated cell (1.5 seconds). The
integration step size of 2.5e-5 seconds leads to 40,000 sample points
per second. Time is given in the first column, potential in the second
column of the files. Each of the three cell arrays is independendly
numbered, cell 0 being in the lower left corner.

Files ff*_spikes, fb*_spikes and pyr*_spikes contain points in time
of spike initiation for selected cells. The respective cells are
marked by black circles in the graphic (cellarrays.eps or
cellarrays.pdf). The first column of the files can be ignored. It has
to be emphasized, that the point in time of spike initiation, not the
point in time of highest peak amplitude is noted. In the case of
pyramidal cells, spike initiation is assumed, if the membrane
potential crosses a threshold of -30 mV. In the case of interneurons,
this threshold equals 0 mV. Therefore, if one compares points in time of spike
initiation as contained in the *_spikes-files against detected points
in time
of highest peak amplitude, one has to allow for a certain difference
of about 0.25 msec. 

Files e120_* contain extracellularly recorded potentials, again, time
in the first column and potential in the second one. The simulated
multi-site recording probe, comprising 13 different recording sites,
is approximately 4 micrometer away from pyramidal cell 40. In the
graphic, the position of the probe is indicated by a red cross. "120"
indicates the opening angle. Cells on the left of the probe that lie
in a 120° sector are recorded from. The individual recording sites are
linearly arranged, perpendicularly to the xy-plane. The lowest
z-coordinate is at -55 micrometer, the highest one at 95
micrometer. Thus individual recording sites have a distance of 12.5
micrometer. 
 
The file signal_noise contains the recorded data from e120_10, but
with added white noise. The SNR equals 21:1, calculated as ratio of
average spike peak-to-peak amplitude and noise rms value
(root-mean-squared).
In this data set, we were able to detect spikes from pyramidal cells
46, 40 and 27.

