The study, by researchers from Canada's University of Toronto Mississauga (UTM), showed that men and women remembered earlier painful experiences differently.
While men (and male mice) remembered earlier painful experiences clearly, women (and female mice) did not seem to forget.
When experiencing pain again, men seemed to be stressed and hypersensitive in remembering, but women were not stressed by their earlier experiences of pain.
"If remembered pain is a driving force for chronic pain and we understand how pain is remembered, we may be able to help some sufferers by treating the mechanisms behind the memories directly," said lead author Loren Martin, Assistant Professor at the UTM.
"What was even more surprising was that men reacted more, because it is well known that women are both more sensitive to pain than men, and that they are also generally more stressed out," Martin added.
For the study, published in the Current Biology journal, the team conducted experiments on both humans and mice where they were taken to specific rooms and made to experience low levels of pain caused by heat delivered to their hind paw or forearm.
Further, human participants were asked to wear a tightly inflated blood pressure cuff and exercise their arms for 20 minutes, while each mouse received a diluted injection of vinegar designed to cause a stomach ache for about 30 minutes.
When the next day the participants returned to either the same or a different room and heat was again applied to their arms or hind paws, men rated the heat pain higher than they did the day before, and higher than the women did.
Similarly, male mice returning to the same environment exhibited a heightened heat pain response, while mice placed in a new and neutral environment did not.
Das, whose 2018 film 'Manto' on famous Urdu author Saadat Hasan Manto would be screened at the 24th Kolkata International Film Festival (KIFF), said the writer had produced his best stories in his worst times.
"It is true artistes, writers, filmmakers flourish most when they go through really bad times," the actor said.
At the same time, she came up with the reference of Ritwik Ghatak and Satyajit Ray as a counter-point and exceptions to her initial argument.
"I don't know if there is a direct connection. Because great filmmakers such as Ritwik Ghatak and Satyajit Ray, processed life differently and reacted to life differently.
"However, the beauty about art remains that pain gives rise to something stronger, something deeper," she observed while delivering the Satyajit Ray Memorial Lecture at the 24th KIFF.
Speaking on the present situation in the world, Das said, "In a way for me, doing Manto was a great pain. As the world today is so full of strife, which is constantly dividing us and telling us how we are different."
Stating that sectarian violence was causing fissures in humanity, she said, "We are divided in the name of religion, caste, gender and colour of skin."
Tracing the life of Manto, who died in 1955 in Lahore at the age of 43, Das said, "Manto had spoken the inconvenient truth and faced hardships in his life. It happens to many of us till this date, when people get imprisoned and I am trolled."
She said to do a film on 'Manto' was not just to introduce viewers to the man he was.
"It is rather to support the Mantos that exist today.
The film will make us uncomfortable collectively as a society," she said.
Saying that the concern, struggle and dilemma of Manto resonated deeply in her own dilemma, struggle and concerns, Das said, "Both my directorial films - Firaaq and Manto - were borne out of compulsions to tell these stories of struggle."
Nawazuddin Siddiqui plays the character of writer Saadat Hasan Manto in the film.
Describing Manto as "one of the pioneers of progressive writing," Das described him as a "deeply sensitive and secular human."
Manto was "very free spirited", she said.
The "only time he did not write (was) during partition.
Some of his famous partition violence stories were written later, Das said during her lecture.
The study underscores the need for efforts to improve sleep among patients with chronic pain and vice versa.
The results suggest that psychological factors may contribute to the relationship between sleep problems and pain, but they do not fully explain it.
"While there is clearly a strong relationship between pain and sleep, such that insomnia increases both the likelihood and severity of clinical pain, it is not clear exactly why this is the case," said lead researcher Borge Sivertsen from the Norwegian Institute of Public Health, Bergen.
The study included more than 10,400 adults from a large, ongoing Norwegian health study. Each participant underwent a standard test of pain sensitivity -- the cold pressor test -- in which the participants were asked to keep their hand submerged in a cold water bath.
Overall, 32 percent of participants were able to keep their hand in the cold water throughout the 106-second test.
Participants with insomnia were more likely to take their hand out early: 42 percent did so, compared with 31 percent of those without insomnia.
Pain sensitivity increased with both the frequency and severity of insomnia.
Pain sensitivity was also linked to sleep latency, the amount of time it takes to fall asleep, although not to total sleep time.
The study was published in the journal Pain.
Until now, to assess pain - a subjective sensation - doctors had to rely on patients self-reporting or the clinical symptoms.
But the novel blood test can help objectively determine how severe a patient's pain is, allowing physicians far more accuracy in treating it.
"We have developed a prototype for a blood test that can objectively tell doctors if the patient is in pain, and how severe that pain is," Alexander Niculescu, Professor of Psychiatry at Indiana University, said.
With an opioid epidemic raging, Niculescu said never has there been a more important time to administer drugs to patients responsibly.
"The opioid epidemic occurred because addictive medications were overprescribed as there was no objective to measure whether someone was in pain, or how severe their pain was," Niculescu said, in a paper detailed in the journal Molecular Psychiatry.
In addition to providing an objective measure of pain, the blood test helps physicians match the biomarkers in the patient's blood with potential treatment options.
The researchers utilise a prescription database to match the pain biomarkers with profiles of drugs and natural compounds catalogued in the database.
"The biomarker is like a fingerprint, and we match it against this database and see which compound would normalise the signature," Niculescu said.
"We have been able to match biomarkers with existing medications, or natural compounds, which would reduce or eliminate the need to use the opioids."
Moreover, the team discovered biomarkers that can also help predict when someone might experience pain in the future - helping to determine if a patient is exhibiting chronic, long-term pain, which might result in future emergency room visits.
Due to financial constraints, Sudam’s parents from Badapokhari village under Oupada block in Balasore district couldn’t afford medical treatment following which the boy suffered leg infection. Later, when some people got to know about his plight through social media, they came forward and helped the family admit the boy to Balasore hospital.
“After knowing about his condition, we brought him to the hospital for treatment. We have even informed the collector who has assured that he will help the family,” a social worker, Sanat Kumar Patra, said.
“He has got ulcers in his legs. After diagnosis, proper treatment will be done,” said Sandeep Das, a doctor who is treating Sudam.
While district administration has assured to help Sudam, Union Minister Pratap Sarangi has said that he will make arrangements for treatment of the minor boy.
Additional Collector Sambit Nayak said, “They can get assistance from Red Cross and CM relief fund for which they have to apply.”
Speaking about the boy, Sarangi said, “Doctors are saying that the treatment can’t be done here so I am looking forward to make arrangements so that he can be admitted to a good hospital.”
Urging the State government to extend help, mother of Sudam said, “I request the govt to provide help so that my son can be operated and he can at least become fit enough to do his own work.”