His most famous book, Awakenings, upon which the 1990 feature film of the same name is based, describes his experiences using the new drug L-Dopa on Beth Abraham post-encephalitic patients.

Mucuna pruriens: improvement of the biotechnological production of the anti-Parkinson drug L-dopa by plant cell selection.

At first, patients respond well to the drug L-dopa, which replaces dopamine, a neurotransmitter that is made by the missing cells.

But in 1969 the drug L-dopa permitted a brief state of grace, enabling Wolpe to compose several works that achieve an extraordinary reconciliation of his methods of pitch organization with a long-dormant lyricism.

When the drug L-dopa was introduced in the late 1960's to treat "ordinary" Parkinson's disease, it was also tried with patients who had the far more severe form of post-encephalitic parkinsonism.

Dr. Knowles then applied the technique to a project to produce the drug L-dopa, which counteracts symptoms of Parkinson's disease, like tremor and rigidity.

It is about the use of the drug L-dopa in the 1960's to "awaken" warehoused victims of sleeping sickness in a mental hospital in the Bronx.

In his 1973 book "Awakenings," for example, Dr. Sacks chronicled what happened when patients "frozen" for decades by encephalitis lethargica were given the drug L-dopa.

Mr. De Niro will play a patient revived by the drug L-dopa after a long diseased-induced sleep.

The standard treatment for Parkinson's disease has been the drug L-dopa, which has proved to be effective in the early stages of the disease but becomes less effective as Parkinsonism becomes more severe.