  The reconstruction of brain neural network connections occurs not only during
the infancy and early childhood stages of brain development, but also in
patients with cognitive impairment in middle and old age under the therapy with
stimulated external interference, such as the non-invasive repetitive
transcranial magnetic stimulation (rTMS) and the transcranial direct current
stimulation(tDCS). However, until now, it is not clear how brain stimulation
triggers and controls the reconstruction of neural network connections in the
brain. This paper combines the EEG data analysis and the cortical neuronal
network modeling methods. On one hand, an E-I balanced cortical neural network
model was constructed under a long-lasting external stimulation of
sinusoidal-exponential form TMS or square-wave tDCS was introduced into the
network model for simulate the treatment process for the brain connections. On
the other hand, by combining Butterworth filter and functional connectivity
algorithm, the paper analyzes the relations between the attentional gamma
oscillation responses and the brain connection based on the publicly available
EEGs during the pre-tDCS and post-tDCS treatment phases. Firstly, the
simulation results indicate that, during long-lasting external stimulations of
tDCS/rTMS, The sustained gamma oscillation was found to trigger more release of
BDNF from astrocytes to participate in the positively reshaping the excitatory
neuronal network connection.
