Blood analysis by Raman spectroscopy for laser stimulation on mouse prefrontal cortex

Low-level laser therapy, a noninvasive physical therapy, is applied to a wide range of conditions and has many effects including anti-inflammatory, analgesic, and anti-allergic effects. Some reports show that low-level laser therapy improves memory for patients. In this study, we explored the effect of laser stimulation on the prefrontal cortex of Alzheimer’s disease model mice. Ten 4-month-old APP/PS1 double-transgenic Alzheimer’s disease model mice were selected for prefrontal cortex stimulation by an 808-nm laser for 40 minutes every day. The peak intensities of blood Raman spectroscopy at 675, 747, 1124 (P < 0.05), 1223 (P < 0.05), 1305, 1340, 1372, 1540, and 1637 cm-1 were different between the laser stimulation group and the control group. The results indicated that laser stimulation of the mouse prefrontal cortex may induce some changes in blood components, such as porphyrins and glucose. Laser stimulation could play a role in the neurophysiological activity, thereby triggering the changes in blood components that could be detected by Raman spectroscopy.