Conclusion
Successful activation of Prestin-expressing neurons suggests that this technology provides non-invasive and spatially precise selective modulation of one or multiple specific brain regions.
Results
The maximum pPrestin expression with the highest cell viability occurred at a pressure of 0.5 MPa, cycle number of 5000, and PRF of 1 Hz. The cellular transfection rate with pPrestin-MBs and US was 20.2 ± 2.5%, which was 1.5-fold higher than that of commercial transfection agents (LT-1). In vivo data suggested that the most profound expression of pPrestin occurred at 2 days after performing pPrestin-MBs with US (0.5 MPa, 240 s sonication time). In addition, no server erythrocyte extravasations and apoptosis cells were observed at US-sonicated region. We further found that with 0.5-MHz US stimulation, cells with Prestin expression were 6-fold more likely to exhibit c-Fos staining than cells without Prestin expression.