Evaluating safe infrared neural stimulation parameters: Calcium dynamics and excitotoxicity thresholds in dorsal root ganglia neurons.

Background: As a promising neural stimulation technique, infrared neural stimulation (INS) has recently gained significant attention due to its ability to stimulate neuronal activities without needing exogenous agents. NIR light is absorbed by water of the tissue producing local thermal effects. Therefore, INS is a suitable candidate for localized and targeted neural stimulation.

In Vivo Evaluation of Thermally Drawn Biodegradable Optical Fibers as Brain Implants.

Optical fiber technology plays a critical role in modern neuroscience towards understanding the complex neuronal dynamics within the nervous system. In this study, we manufactured and characterized amorphous thermally drawn poly D, L-lactic acid (PDLLA) biodegradable optical fibers in different diameters. These optical fibers were then implanted into the lateral posterior region of the mouse brain for four months, allowing us to assess their degradation characteristics.

In vivo brain temperature mapping using polymer optical fiber Bragg grating sensors.

Variation of the brain temperature is strongly affected by blood flow, oxygen supply, and neural cell metabolism. Localized monitoring of the brain temperature is one of the most effective ways to correlate brain functions and diseases such as stroke, epilepsy, and mood disorders. While polymer optical fibers (POFs) are considered ideal candidates for temperature sensing in the brain, they have never been used so far in vivo.