Repeated administration of morphine sensitizes animals to the stimulant and rewarding properties of the drug. It may also alter the expression and function of GABA receptors within the ventral tegmental area (VTA), a midbrain region that is implicated in morphine action. In the present study, the effect of activation of GABAB receptor subtypes within the VTA on morphine-induced incentive sensit...

BACKGROUND The purpose of this study was to investigate whether ultra-low-dose chest computed tomography (CT) can be used for visual assessment of CT features in patients with pulmonary alveolar proteinosis (PAP) and to evaluate the relationship between the quantitative analysis of the ultra-low-dose CT scans and the pulmonary function tests (PFTs). METHODS Thirty-eight patients (mean [SD] ag...

The present study focused on the effects of 1-amino-3,5-dimethyladamantane (memantine), a clinically used, low-affinity N-methyl-D-aspartate channel blocker, on the motivational impact of morphine and morphine withdrawal syndrome. Memantine (7.5 mg/kg) inhibited the acquisition as well as the expression of morphine-induced conditioned place preference. However, memantine did not affect signific...

Introduction: Response to morphine and role of Nitric Oxide (NO) on expression of morphine response has been studied in vertebrates. But, little evidence is provided in the matter in earlier invertebrates. This investigation for the first time evaluated the effect of NO on expression of morphine potency in Paramecium caudatum. Methods: Animal after isolation from natural media and specific i...

PURPOSE To define the dose ratio between morphine and methadone in relation to the previous morphine dose and the number of days needed to achieve the same level of analgesia in a group of patients with advanced cancer with pain who switched from morphine to oral methadone. PATIENTS AND METHODS A cross-sectional prospective study of 38 consecutive cancer patients who switched from morphine to...

Introduction: The GABAergic system of the brain plays a key role in morphine tolerance and sensitization. As isoniazid is a modulator of the GABAergic system, the present study aims to understand whether isoniazid can influence the induction of tolerance and sensitization to the rewarding effects of morphine.  Methods: The rewarding effects of morphine and isoniazid were assessed using a Condi...

Morphine has been widely used for the treatment of acute, chronic, and cancer pain and is considered the strongest analgesic in clinical care. Conversely, morphine-induced analgesia may be accompanied by several side effects. Animal studies have demonstrated that low doses of morphine administered intrathecally can produce reliable analgesia for thermal, mechanical, and chemical nociceptive sti...