Breathing restored after severe spinal-cord injury

70652986 — Mon, 26 Mar 2007 06:21:35 -0400

Keeping an animal functioning after a cervical spinal cord injury is nearly impossible. An American researcher developed the lower spinal cord rat model in the early 1900s. He found that lesioning the spinal cord of dogs between the eighth and tenth thoracic vertebrae produced hind-limb paralysis while letting animals stay self-sufficient. Yang Teng, director of spinal cord injury research at the West Roxbury Veterans Administration Medical Center (WRVA), first observed very transient breathing disorders while working on a rat version of the model in graduate school. One of his professors had shown that morphine's respiration-suppressing effects could be counteracted by the serotonin agonist 8-OH DPAT. Teng tried that drug and buspirone on the lower thoracic-injured rats. "It restored their breathing," he said. "But we knew that the underlying cause of loss of respiratory function in lower- thoracic injury is very different from cervical injury - different neuromuscular systems are involved."

Teng and Howard Choi, Harvard Medical School clinical fellow in physical medicine and rehabilitation, hypothesized that administering a contusion to half of the spinal cord would keep a cervically injured rat alive. Delivering such a lesion turned out to be difficult. The spinal cord is buried deep inside the body at the neck and thorax.

Choi began his experiments. In the earlier study, Teng delivered serotonin agonist one day after injury and restored breathing in the lower thoracic-injured rats for four hours. Choi delivered the drug four days after injury. Breathing was restored for the same length of time.

Breathing easier after spinal cord injuries

50443248 — Tue, 24 Jul 2007 12:21:29 -0400

njuries to the upper spinal cord can take a victim's breath away.
Most people don't know that breathing difficulties are the leading cause of disease and death after such injuries. Indeed, respiratory failure causes more deaths than limb paralysis does, and survivors often become dependent on ventilation machines.

For the first time, Harvard researchers successfully tested an inexpensive, readily available class of drugs that has restored normalcy to rats who suffered the same loss of breath as humans who receive spinal cord injuries in combat, falls, car wrecks, or by gun or knife. These drugs include buspirone, a tranquilizer used to ease anxiety in the elderly and to help people quit smoking.

all Howard Choi stories

Breathing restored after severe spinal-cord injury

Breathing easier after spinal cord injuries