United News of Bangladesh

Scientists in China have identified why people with chronic pain often feel more discomfort at night than during the day. The research, led by Zhang Zhi from the University of Science and Technology of China, was published Friday in the journal Science. Although it has long been known that pain follows a daily pattern—usually milder during active hours and stronger during rest—the exact reason was not clear. Scientists were aware that the brain’s internal clock, called the suprachiasmatic nucleus, controls sleep and hormones, but its role in pain was not fully understood. Using advanced techniques, researchers traced a specific nerve pathway in mice linking this brain clock to the spinal cord. They found that this pathway is influenced by the body’s natural daily rhythm. Since mice are active at night and rest during the day, the pattern is opposite to humans. During their resting period, the brain clock is more active, which increases pain signals. When the mice are active, the brain activity drops, reducing the intensity of pain. The findings help explain why pain sensitivity changes over the course of a day. Researchers say this discovery could help improve pain treatment by timing medications according to the body’s natural biological clock.