Abstract
We propose and demonstrate the laser-induced perturbation of neuronal cells with a focused laser beam.
As one approach for realizing the intracellular manipulation of synapses, we evaluated the optical
trapping and assembling dynamics of synaptic vesicles or quantum-dot conjugated molecules on neurons
by fluorescence analysis. When a near-infrared laser for optical trapping is focused on the synaptic
vesicles or molecules, the fluorescence intensity gradually increases with the laser irradiation time,
suggesting that the trapping force causes molecular assembly at the laser focus. The molecular dynamics
in an optical trap, which is obtained from fluorescence correlation spectroscopy, shows that the motion is
constrained at the focus due to the optical trapping force. We also applied a focused femtosecond laser
for direct cutting and precise stimulation of a single neuron in the neuronal network. Our methods have
the potential to modulate the synaptic transmission of a particular neuron in neuronal networks without
any drugs.
