Fig. 2

Area measurement diagram. A: illustrates the furthest point of diffusion of UCA along the caudal side of the skull. B: shows a simulated diagram of UCA diffusion area using Photoshop software. C: The diagram illustrates the diffusion range of MB after dissection. Point a represents the furthest point of diffusion towards the head side, while point b represents the furthest point of diffusion towards the tail side