3.3. Electrophysiological activity analysis
The electrical activity of neurons is an extensive integration of
neuronal ion channel function. These ion channel proteins are
transported by axons to specific locations to establish neuronal
polarity and influence synaptic plasticity.[24]Hence, electrophysiological activity is regarded as a key indicator to
inspect whether the neuron is physiological disordered or
diseased.[25,26] To explore the effect of gene
transfection on the physiological activity of neurons, the
electrophysiology assays of non-transfected (Figure 3A) and transfected
(Figures 3B and 3D) primary cultured neurons were conducted. Membrane
potential was maintained at -60 mV with a current clamp model via
adjusting injection current properly range from -10 pA to -15 pA. The
stimulus program was run successively from -20 pA to 70 pA by 10 pA
steps (Figure 3C). We found that the induced action potential of primary
cultured hippocampal neurons took place when the injection current was
30 pA. With the injected current going up, the frequency of evoked
action potentials increases (Figure 3E). In the transfected neurons, a
similar electrophysiological
result was observed (Figure 3F), indicating that the expression of
mCherry protein did not affect the physiological state of neurons after
transfection. Moreover, the electrophysiological results in combination
with the results of the entire axon structure (Figure 1) and microtubule
skeleton architecture (Figure 2B), as well as unaffected Tuj-1
expression (Figure S1) after transfection suggested the transfection
strategy has a minimal side effect on the physiological state of neurons
during the imaging period.