Abstract: Objective To examine the effects of intracerebroventricular administration of adrenomedullin (AM) on the expression of Fos and the spontaneous electrical activity of area postrema (AP) neurons in sino-aortic denervated rats. Methods Using immunohistochemistry for Fos and extracellular recording technique, to determine the expression of Fos and the spontaneous electrical activity of AP neurons in male Sprague-Dawley rats, respectly. Results Following Intracerebroventricular administration ofAM (1 nmol/kg, 3 nmol/kg), Fos-like immunoreactive (Fos-LI) 基金项目：河北省教育厅科研项目（2005101） neurons and the discharge rate of AP neurons were markedly increased. Pretreatment with calcitonin gene-related peptide(CGRP) receptor antagonist CGRP8-37 (30 nmol/kg) significantly reduced the effects of AM (3 nmol/kg). Conclusions AM may activate the neurons in AP via CGRP receptors.