Despite all the recent achievements in the neuroscience, the questions that have motivated scientists about the information processing in individual neurons still remain unanswered. Studying neuronal behaviour in vitro facilitates the availability of a single neuron investigation, but requires non-invasiveness with high spatial and temporal resolution. Expansion of the neurophysiologic recording toolbox with the optogenetic stimulation has enabled such recordings. The included work shows the usage of genetically encoded voltage-sensitive fluorescent proteins as a non-invasive optogenetic tool for recording electrophysiological signals in electrogenic cells. The cortical neurons have been transduced with the new constructs, hSyn_ArcLight and hSyn_Butterfly by recombinant adeno-associated viral vectors. These novel constructs, specifically expressed in the neuronal cells, have been evaluated by electrophysiological experiments with electrical stimulations recorded optically. It has been shown that ArcLight A-242 is a valuable tool for recording and detection of single action potentials. Although not successful so far (due to the available equipment), Butterfly should be an even more reliable tool for the detection of even sub-threshold potential changes. Going forward, it might be assumed that the optogenetic toolbox, enriched by those two components, is a step closer to non-invasive, optical monitoring of neural electrical activity.