The present study examined the role of vagal innervation of the rat esophagus in nociception. Electromyographic recordings from neck muscles were used as indicators of pseudoaffective reactions in lightly anaesthetized animals; responses were obtained during mechanical (distension) and chemical (HCI) nociceptive stimulation of the upper cervical (4.5cm from incisors) and midthoracic (7cm from incisors) esophagus. Compared to midthoracic esophageal stimulation, stimulation of the upper esophagus produced more vigorous responses. Bilateral transections of the cervical vagus and superior laryngeal nerves led to a gradual diminution of responses to upper stimulation, while the same manoeuvre increased responses to lower esophagus stimulation. These results suggest a contribution of vagal afferents to pseudoaffective responses elicited by noxious stimulation of the upper esophagus. (C) 2003 Elsevier Science Ltd. All rights reserved.