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Fig. 1 Morphology of normal CB-HRP cells (boxes circled) and the expression of NeuN and 5-HT in CSF-contacting nucleus of rats

Fig. 2 Changes of immunofluorescence in CSF-contacting nucleus after intracerebroventricular injection（Red represent CB-SAP labelled cells）

Fig. 3 Changes in immunofluorescence of FJC labelled cells in CSF-contacting nucleus after intracerebroventricular injection（Green represent FJC labelled cells）

Fig. 4 Changes in immunofluorescence for 5-HT expression in spinal dorsal horn after intracerebroventricular injection（Green represent 5-HT positive cells）

Fig. 5 Changes in immunofluorescence for c-Fos expression in spinal dorsal horn after intracerebroventricular injection（Green represent c-Fos positive cells）