Restraint water-immersion stress (RWIS) is considered a compound stress model as it includes both psychological and physical stimulation. Studies have shown that neurons are involved in RWIS, but the role of astrocytes in RWIS has not been reported as yet. Here, we tested our hypothesis that astrocytes are involved in RWIS and interact with neurons in the brainstem to regulate gastric mucosal damage induced by RWIS. RWIS of different durations (0.5, 1, 2, 3, and 5 h) induced significant gastric mucosal damage and activated astrocytes by increasing the expression of glial fibrillary acidic protein and neurons, as indicated by the Fos expression in the nucleus of solitary tract and the dorsal motor nucleus of the vagus. Intracerebroventricular administration of both astroglial toxin L-α-aminoadipate and c-fos antisense oligodeoxy nucleotides reduced RWIS-induced gastric mucosal damage. Immunohistochemistry results showed that L-α-aminoadipate decreased the activation of both astrocytes and neurons by RWIS. Similarly, antisense oligodeoxy nucleotides significantly suppressed activation of both neurons and astrocytes induced by RWIS. Our data showed that astrocytic and neuronal activations may be closely related to the gastric mucosal damage induced by RWIS through reciprocal ‘crosstalk’. This study suggests that an intervention targeting this interaction may offer some novel therapeutic strategies for gastric ulcers.