Abstract:

Objective     To investigate activity of cholinergic neurons in the dorsal motor nucleus of the vagus (DMV) in response to water-immersion stress (RWIS) in rats. Methods     Ten rats were randomly divided into the control group and the RWIS group. Fos-immunoreactive (Fos-IR), choline acetyltransferase immunoreactive (ChATIR) and double labeled (Fos/ ChAT-IR) neurons were counted using dual Fos and ChAT immunohistochemistry. Results     Compared with unstressed rats, FosIR neurons dramatically increased in the DMV of RWIS rats (P<0.01), and Fos expression was higher in the caudal portion of the NTS compared with the rostral and intermedial portions. ChAT-IR neurons decreased and were mainly observed in the caudal and intermediate portions of the DMV in RWIS rats（P<0.01）. Percentages of Fos/ ChAT-IR norons in ChAT-IR neurons in unstressed and RWIS rats were 7.17% and 21.12%, respectively（P<0.01）. Conclusion     Cholinergic neurons in DMV are involved in the stress response.

Key words: Stress; Dorsal nucleus of vagus; Choline 0-acetyltransferase; Fos; Rats