FOS and Parkinson disease: In line with these data, a study conducted in a chronic PD mouse model showed motor function improvement following repeated applications of STN-fTUS (two sessions per week for 5 consecutive weeks, 3.8 MHz, 1 kHz PRF, 50% DC, 1 s SD, 4 s ISI, 430 mW/cm2 ISPTA), which was associated with increased expression of c-Fos in the STN, a marker of neuronal activity.