Figure 2: Shift of Fos expression pattern from fusiform to deep layer of DCN by varying the type of stimulation in nimodipine treated rats. (A) Fos expression (black dots) in superficial regions of DCN after 2 h of dummy implantation. Scale bar: 200 μm. (B) After 2 h of stimulation at 1.6 Hz Fos positive nuclei were observed predominantly in the superficial DCN layer. (C+D) 2 h of stimulation at 50 Hz (C) and 400 Hz (D) led to a high and mostly tonotopic Fos expression within the deep layer of DCN.