COLLEGE STATION - Victims of debilitating spinal cord injuries may in the future have greater chances for recovery of some locomotive functions, thanks to pioneering spinal cord research by Texas A&M University neuroscientist James Grau.
Grau, who has studied the spinal cord for more than a decade, has helped advance the concept that the spinal cord - long considered to be only a simple conduit for the relaying of impulses to and from the brain - is capable of learning without the brain.
"It appears the spinal cord is far smarter than most assume," Grau says. He says his animal models have demonstrated neurons in the spinal cord are capable of different types of advanced learning, acting as a "back-up system" when communication with the brain is disabled.
Normally, the brain is responsible for locomotive activities and inhibits the spinal cord's learning abilities. However, given a potentially catastrophic set of events, the spinal cord can take on extra responsibilities that include the ability to learn locomotive function, Grau explains.
The ability of the spinal cord to learn, which is referred to as "plasticity," has come to the forefront of the scientific community within the last five years thanks to Grau and his colleagues, but Grau's continued research has taken spinal cord plasticity into uncharted territory.
While spinal cord plasticity has been the focus of experts throughout the United States and Europe, Grau and former student Robin Joynes' work on the phenomenon of "learned helplessness" in the spinal cord is unique to Texas A&M, Grau says.
Just as the brain can experience learned helplessness, resulting from believing it has no control over environmental stimuli, so too can the neurons in the spinal cord, he explains.
Because learned helplessness destroys the spinal cord's ability to learn, Grau says, the chances for locomotive recovery in subjects experiencing this phenomenon are far less.
"We have identified an environmental event that appears to hurt spinal cord plasticity, and this could impede the recovery of function," he says.
The tissue damage that often accompanies a spinal cord injury could set off a set of events that trigger learned helplessness in the spinal cord, Grau notes.
Not only has Grau identified this degradative process, but he and graduate student Eric Crown have also discovered a way to prevent learned helplessness from occurring, he says.
"We recently discovered that we could prevent the learned helplessness phenomenon prior to the noncontingent stimuli by having the subject undergo a period of instrumental training," Grau says. "The training appears to immunize the neurons in the spinal cord against developing a learned helplessness."
In other words, giving the spinal cord the opportunity to learn beforehand seems to induce a process that protects the spinal cord and prevents the deficit, he says.
Of perhaps even greater clinical significance, Grau says subjects given this instrumental training after the development of the learned helplessness, can have the learning capacity of their spinal cord neurons restored - erasing the learning deficit.
Grau is no stranger to the ways in which the spinal cord can learn.
With the help of his former graduate assistant, Juan Salinas, Grau extended the concept of spinal cord plasticity by showing that the spinal cord could support a number of advanced Pavlovian effects that were previously thought to depend on the brain. These processes are characterized as reflecting a shift in attention, Grau explains.
He says he hopes his research will help to develop new behavioral and pharmacological treatments to foster recovery after spinal cord injuries.
"In the early 1900s a spinal cord injury almost certainly meant death, but with the advances in spinal cord research, I believe that most people who experience a spinal cord injury will recover some motor function," Grau says.
Journal
Journal of Neurophysiology