This dir deals with the fibres providing inputs to the
neurons of the network, and hence driving the network.

Fibres are Poisson processes whose instantaneous spike 
rate can be modulated by another process: 
- a point  process (with exponential decaying response) 
for forward fibres projecting from external sources
(Harsch-Robinson_modulation.g); 
- the filtered membrane potential of a component neuron
for intracolumnar (hence feedback) fibres 
(Firing_rate_modulation.g).

The files contain procedures for creating the fibres, 
positioning them, assigning them to different populations 
(excitatory versus inhibitory, feedforward versus 
intracolumnar feedback), connecting them to synapses on 
the neurons' compartments, and adapting their strengths 
according to their depth (layer) within the neocortex
(Firing_rate_profile.g).

The actual connections from the different fibre populations
to the individual neurons are laid by code within the main script 
(../Network/Network_make.g), using procedures described here.
The reason for coding these connections in the main script,
is that they have to be tuned by hand for each neuron separately,
in order to guarantee that each neuron would spike at a reasonable 
rate.