Pain modulation .Brain circuits modulate the activity of the pain transmission pathways One circuit has links in the hypothalamus midbrain and medulla It controls spinal pain-transmission neurons through a desending pathways eIt is bidirectional produce analgesia or increase painPain modulation •Brain circuits modulate the activity of the pain￾transmission pathways •One circuit has links in the hypothalamus, midbrain, and medulla •It controls spinal pain-transmission neurons through a desending pathways •It is bidirectional produce analgesia or increase pain