Related Experiment Video
Updated: Jul 12, 2026
07:23
Assessment of Morphine-induced Hyperalgesia and Analgesic Tolerance in Mice Using Thermal and Mechanical Nociceptive Modalities
Published on: July 29, 2014
Morphine analgesia in grouped and isolated rats
Psychopharmacologia
|January 1, 1975
Summary
Long-term isolation in male rats did not alter their pain perception or response to morphine analgesia, even in those exhibiting aggressive behaviors. This suggests isolation does not impact morphine
Area of Science:
- Neuroscience
- Behavioral Science
- Pharmacology
Background:
- Social isolation in young adulthood can induce behavioral changes.
- Investigating the impact of isolation on pain perception and drug response is crucial.
Purpose of the Study:
- To determine if long-term social isolation affects pain thresholds.
- To assess the influence of isolation on morphine-induced analgesia in male rats.
Main Methods:
- Young adult male rats were subjected to chronic social isolation.
- Behavioral changes, including muricidal behavior, were observed.
- Analgesic effects of morphine were evaluated using tail compression and hot plate tests.
Main Results:
- Chronically isolated rats did not exhibit altered pain thresholds.
- Morphine's analgesic efficacy remained unchanged in isolated rats.
- Muricidal behavior did not correlate with changes in pain response or morphine analgesia.
Conclusions:
- Long-term social isolation does not modify pain sensitivity in male rats.
- The analgesic effects of morphine are not affected by chronic isolation.
- Behavioral alterations due to isolation do not influence pain modulation pathways targeted by morphine.
Related Concept Videos
01:25Analgesia and Pain Management
Pain is critical to various clinical pathologies, provoking an urgent need for effective management. Pain, whether acute or chronic, is a complex neurochemical process. Its alleviation depends on the type, with nonopioid analgesics effective for mild to moderate pain, such as musculoskeletal or inflammatory pain, while neuropathic pain responds best to anticonvulsants, tricyclic antidepressants, or serotonin/norepinephrine reuptake inhibitors. For severe acute or chronic pain, opioids may be...
01:20Opioid Analgesics: Morphine and Other Natural Cogeners
Opioids are a class of drugs that mimic endogenous opioid peptides and act on opioid receptors, and help in pain relief. These compounds are classified as natural, synthetic, or semi-synthetic. Natural opioids, like morphine, codeine, and thebaine, are derived from the opium poppy plant (Papaver somniferum or Papaver album) and are termed opiates. Synthetic opioids are artificial, while semi-synthetic opioids combine natural and synthetic compounds. Morphine, a prototypical opioid, possesses a...
01:15Opioid Analgesics: Synthetic and Semisynthetic Opioids
Synthetic and semisynthetic opioids are pivotal in pain management and tackling opioid addiction. Semisynthetic opioids, including morphinans (morphine derivatives), oxycodone, oxymorphone, hydrocodone, and hydromorphone, have improved pharmacokinetic profiles compared to morphine. Additionally, heroin and 6-MAM (6-Monoacetylmorphine) show better CNS penetration than morphine due to heightened lipid solubility. Hydromorphone, a potent opioid, undergoes hepatic metabolism to form the active...