Fig. 4.

Effects of MS-DBS on spatial memory based on the stimulation time. a All the groups gradually acquired the location of the platform. After 48 h from the last training trial, all the groups were administered a probe test. b The speed was not different among the groups. c The time spent in the target quadrant (in which the platform was placed) was slightly decreased in all the lesion groups. d The time spent in the platform zone (in which the platform was placed, 0.15 m in diameter) was significantly decreased in the group with cholinergic lesions compared with normal group (*p = 0.02). However, the time spent in this zone was increased by stimulation. The time spent of pre-stimulation group was significantly increased than lesion group (^† p < 0.05). e The number of platform crossings was also reduced in the cholinergic lesion group and increased in all stimulation groups