The possibility of measurement of the electrical activity of neurons by Light-Addressable Potentiometric Sensor (LAPS) is investigated in this article. For the measurement of the extracellular transient of the neural action potential, which is very low, at the surface of a LAPS heterostructure, a simple structure like SiO2/Si, instead of the conventional Si3N4/SiO2/Si heterostructure, is studied. The SiO2 surface was modified by Poly-L-Ornithine and Laminin (PLOL). Experimental results show that the PLOL coating on the SiO2 surface not only prevents the hydration of the SiO2 layer and thus enables us to use SiO2 only as the insulating layer, but also, provides an efficient culturing of neurons of Lymnaea stagnalis, a kind of sea snail, on the SiO2 surface. The PLOL modified SiO2 layer of the novel LAPS heterostructure, is kept in contact with the neuron-culture medium for ten days mimicking the maximum cell-culturing period. There is no appreciable change in the sensor response was observed during this period. A DC bias, superimposed by a 2 mVp-p and 800 Hz AC was applied to the sensor to simulate an extracellular transient of 2 mVp-p to the surface and the response of the sensor shows the possibility of the measurement of the neural action potential by the LAPS.