Debate on Insects Feeling Pain Finally Gets a Verdict

Scientists have a contentious disagreement over whether or not insects can feel pain.

A group of researchers claimed in a study released recently that these animals have a particular biological mechanism that suggests they may have a subjective experience of pain.

The researchers concluded that insects most likely have central nervous system control over nociception, or the detection of potentially harmful stimuli, and that this is consistent with the existence of a pain experience after reviewing a variety of scientific evidence.

Nociception

Nociception typically causes reflex-like responses, such as a quick withdrawal from or escape from harmful stimuli, according to Matilda Gibbons, the paper's lead author from the Queen Mary University of London's (QMUL's) School of Biological and Behavioural Sciences in the U.K.

According to experts, pain is a negative subjective experience created by the brain.

There are times that it can accompany nociception.

Such reflexes, according to Gibbons, may not always be accompanied by an objective experience of pain or suffering, even in relatively simple animals like worms.

She also questioned how, in contrast to basic nociception, one might judge the likelihood of pain in an animal.

Descending Control of Nociception

Although the existence of basic nociception in insects has been well established, it is unknown whether these creatures possess the capacity to regulate (or "modulate") nociception, a trait shared by beings like humans who do experience pain subjectively.

For instance, neurons in the brain of mammals carry out this ability, which researchers refer to as the descending control of nociception.

This skill serves a crucial adaptive purpose by allowing an animal to modify its behavior in various situations to put survival first.

According to the authors' research, if an animal sustains an injury during combat, dampening its nociceptive processing may improve its fighting prowess by preventing it from wasting time or energy on responding to the injury.

However, it has rarely been studied whether or not insects possess this kind of control, let alone the neural circuits needed for it.

According to Gibbons, one characteristic of human pain perception is that it can be altered by brain-derived nerve signals.

Due to the body's opiates' ability to block the nociceptive signal, soldiers may occasionally be unaware of serious injuries sustained on the battlefield.

She said that some people can also consciously grit their teeth and endure the pain if their bravery results in a reward or boost to their reputation.

The team questioned whether the insect brain has the neural components necessary to support pain-like experiences rather than merely basic nociception.

Flexibility in Behavior

After reviewing a range of neurobiological and behavioral evidence, the authors found that insects likely do have a neural system for dampening their responses to potentially-painful stimuli so the insects can apply flexibility in behavior by adapting to different contexts, similar to the natural instinct of humans.

Gibbons said that the function of this dampening in nociception in humans is to reduce our pain in situations where feeling pain is unhelpful.

The reserchers propose that if insects also have this capacity, it is possible that insects have evolved a similar pathway to cope with or react to feelings of pain.

As of the moment, there are no conclusive methods for measuring the pain felt by insects, making the findings of the study a highly significant leap in terms of the subject, Newsweek reports.