Modulation of neuronal activity via plasmonic nanoparticles

The use of light to control neuronal activity has become an emerging field of research that may enable new neurotechnologies for monitoring brain activity. One of the most promising and yet underexplored nanomaterials for neuronal photoactivation are plasmonic nanoparticles that by converting light into heat, they can stimulate neurons through activation of thermosensitive channels. Here we show experimental evidences on photo-modulation of primary CTX neurons by using anisotropic gold nanoparticles and IR laser irradiation. Gold nanoparticles are retained on cell membrane by selective targeting of AMPAr receptors as shown by transmission electron microscopy image analysis. The neuromodulation was performed in a multielectrode array system (MEAs) using matrix of 16 electrodes and coupled to laser-system. We observed that the length of the laser pulse influences the mean firing rate of neurons: the shorter the pulse laser, the higher the activity. Also, the exposure of neurons to the laser and nanoparticles does not show any cytotoxic effects. This approach can be used to locally modulate neuronal activity.