Figure 4.

Adult lesion. A subset of 16 excitatory (and 5 inhibitory) neurons lost their input at time step 1000 (vertical line) when network connectivity is stable (‘adult networks’). Left column again summarizes changes within the LPZ whereas the right column shows the same for neurons outside the LPZ. (A,B) Course of excitatory synapse numbers per neuron over time from 12 individual simulations. (C,D) Course of mean firing probability (black curve) and mean excitatory synapse numbers (red curve) averaged over simulations in (A,B). There is an overall loss in synapses numbers in the LPZ as well as in intact regions. Thus, neurons which lost their input will not reach homeostasis after the lesion again. However, neurons that kept their input are able to regain homeostasis. (E,F) Gives the development of synaptic elements over time averaged over the simulations in (A,B). Within the lesion projection zone there is a lack of vacant axonal elements but a high demand of synaptic input expressed by an increased number of vacant excitatory dendritic elements. Neurons outside the lesion projection zone respond with moderate axonal sprouting.