Related Experiment Video
Updated: May 31, 2026
06:41
Electronic von Frey associated with the Mouse Grimace Scale to Assess Allodynia and Pain in Trypanosoma evansi-Infected Mice
Published on: July 19, 2024
Pain and suffering in invertebrates?
1School of Biological Sciences, Medical Biology Centre, Queen's University Belfast, Northern Ireland. r.elwood@qub.ac.uk
ILAR Journal
|June 29, 2011
Summary
Distinguishing animal pain from nociception is challenging. Behavioral evidence, like learning and memory, suggests some invertebrates may experience pain, warranting more humane care.
Area of Science:
- Comparative physiology
- Animal behavior
- Neuroscience
Background:
- Nociception is a protective reflex to tissue damage found in most animals.
- Pain experience, involving memory and behavior modification, may offer enhanced long-term protection.
- Distinguishing pain from nociception across diverse taxa is a significant scientific challenge.
Purpose of the Study:
- To review criteria for differentiating nociception from pain in animals.
- To assess the evidence for pain experience in invertebrates.
- To inform ethical considerations in animal care.
Main Methods:
- Review of scientific literature on nociception and pain criteria.
- Analysis of behavioral responses to noxious stimuli.
- Evaluation of physiological and neurological indicators.
Main Results:
- Nociceptor presence alone is insufficient to confirm pain.
- Opioid and analgesic effects do not definitively distinguish pain from nociception.
- Behavioral indicators such as rapid avoidance learning, prolonged memory, and complex grooming suggest pain in some invertebrates.
Conclusions:
- Available data suggest pain, beyond mere nociception, may exist in some invertebrates.
- Behavioral evidence is most insightful for inferring pain experience.
- Conclusive data remain limited, supporting a precautionary approach for humane invertebrate care.
More Related Videos
Related Concept Videos
01:29Blood and Nerve Supply to the Bones
Bones are dynamic organs that require a rich supply of oxygen and nutrients. Around 5% to 10% of the cardiac output supplies blood to the bones. A typical long bone has three main sources: the nutrient artery, the metaphyseal and epiphyseal arteries, and the periosteal arteries.
Nutrient Artery
The nutrient artery is the main blood vessel that enters the diaphysis via the nutrient foramen. While most long bones have only one nutrient foramen, large bones, such as the femur, may have two. This...
Nutrient Artery
The nutrient artery is the main blood vessel that enters the diaphysis via the nutrient foramen. While most long bones have only one nutrient foramen, large bones, such as the femur, may have two. This...
01:44Nociception
Nociception—the ability to feel pain—is essential for an organism’s survival and overall well-being. Noxious stimuli such as piercing pain from a sharp object, heat from an open flame, or contact with corrosive chemicals are first detected by sensory receptors, called nociceptors, located on nerve endings. Nociceptors express ion channels that convert noxious stimuli into electrical signals. When these signals reach the brain via sensory neurons, they are perceived as pain. Thus, pain helps the...
01:20Pain
Pain serves as a critical warning signal that alerts the body to potential or actual harm. When mechanical pressure on the skin is intense, such as from a sharp pinch, the sensation transitions from touch to pain. Similarly, extreme temperatures, like a hot pot handle, convert the sensation of heat into pain. Pain can also result from overstimulation of other senses, such as blinding light, loud noise, or the intense heat from habañero peppers. This ability to sense pain is essential for...